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BIOLOGY (1418 journals)            First | 1 2 3 4 5 6 7 8 | Last

Showing 1201 - 1400 of 1720 Journals sorted alphabetically
Regulatory Peptides     Hybrid Journal   (Followers: 9)
Reports in Parasitology     Open Access   (Followers: 2)
Reports on Mathematical Physics     Full-text available via subscription   (Followers: 1)
Reports on Progress in Physics     Full-text available via subscription   (Followers: 3)
Reproductive Biology     Full-text available via subscription   (Followers: 1)
Reproductive Biology Insights     Open Access   (Followers: 2)
Reproductive Biomedicine & Society Online     Open Access  
Reproductive Toxicology     Hybrid Journal   (Followers: 13)
Research & Reviews : Journal of Computational Biology     Full-text available via subscription   (Followers: 3)
Research & Reviews : Journal of Ecology     Full-text available via subscription   (Followers: 1)
Research and Reports in Biodiversity Studies     Open Access  
Research and Reports in Biology     Open Access  
Research in Engineering Design     Hybrid Journal   (Followers: 11)
Research Journal of Parasitology     Open Access   (Followers: 3)
Research Journal of Seed Science     Open Access   (Followers: 4)
Research Journal of Soil Biology     Open Access   (Followers: 2)
Research Journal of Toxins     Open Access  
Resources     Open Access  
Retrovirology     Open Access   (Followers: 1)
Reviews in Fish Biology and Fisheries     Hybrid Journal   (Followers: 32)
Reviews of Modern Physics     Full-text available via subscription   (Followers: 28)
Revista Argentina de Antropología Biológica     Open Access  
Revista Brasileira de Biociencias     Open Access  
Revista Brasileira de Biologia     Open Access  
Revista Brasileira de Fisiologia Vegetal     Open Access  
Revista CENIC. Ciencias Biológicas     Open Access  
Revista Ceres     Open Access  
Revista Ciencias Marinas y Costeras     Open Access  
Revista Cubana de Investigaciones Biomédicas     Open Access   (Followers: 1)
Revista de Biología Tropical     Open Access   (Followers: 2)
Revista de Ciencia y Tecnología     Open Access  
Revista de Ciências Agroambientais     Open Access  
Revista de Educación en Biología     Open Access  
Revista de la Ciencia del Suelo y Nutricion Vegetal     Open Access  
Revista de Protección Vegetal     Open Access  
Revista Eletrônica TECCEN     Open Access  
Revista Fitotecnia Mexicana     Open Access  
Revista Iberoamericana de Bioética     Open Access  
Revista Iberoamericana de las Ciencias Biológicas y Agropecuarias     Open Access  
Revista Iberoamericana de Micología     Full-text available via subscription  
Revista Latinoamericana de Bioética     Open Access  
Revista Mexicana de Biodiversidad     Open Access  
Revista Mexicana de Micologí­a     Open Access  
Revista Peruana de Biología     Open Access  
Revue de primatologie     Open Access  
Revue d’ethnoécologie     Open Access   (Followers: 1)
Rhodora     Full-text available via subscription  
Rice     Open Access   (Followers: 5)
Rice Science     Open Access   (Followers: 3)
Risk Analysis     Hybrid Journal   (Followers: 35)
RNA     Hybrid Journal   (Followers: 9)
RNA & Disease     Open Access   (Followers: 1)
RNA Biology     Full-text available via subscription   (Followers: 4)
RURALS: Review of Undergraduate Research in Agricultural and Life Sciences     Open Access   (Followers: 1)
Russian Journal of Biological Invasions     Hybrid Journal   (Followers: 1)
Russian Journal of Developmental Biology     Hybrid Journal   (Followers: 2)
Russian Journal of Marine Biology     Hybrid Journal   (Followers: 2)
Russian Journal of Mathematical Physics     Hybrid Journal  
Russian Physics Journal     Hybrid Journal   (Followers: 1)
Rwanda Journal     Full-text available via subscription  
Saudi Journal of Biological Sciences     Open Access   (Followers: 2)
Science and Engineering Ethics     Hybrid Journal   (Followers: 9)
Science Bulletin     Hybrid Journal  
Science China Life Sciences     Open Access  
Science Signaling     Full-text available via subscription   (Followers: 19)
Science Technology & Society     Hybrid Journal   (Followers: 4)
Scientific Journal of Biological Sciences     Open Access   (Followers: 1)
Scientific Papers Animal Science and Biotechnologies     Open Access  
Scientific Reports     Open Access   (Followers: 43)
Scientific Research Journal     Open Access  
Scientifica     Open Access  
SCIMETR : International Journal of Science     Open Access  
Seed Science and Technology     Full-text available via subscription   (Followers: 3)
Selection     Full-text available via subscription  
Self/Nonself - Immune Recognition and Signaling     Full-text available via subscription   (Followers: 2)
Selforganizology     Open Access  
Semiconductor Science and Technology     Open Access  
Seminars in Cancer Biology     Hybrid Journal   (Followers: 3)
Seminars in Cell & Developmental Biology     Hybrid Journal   (Followers: 6)
Seminars in Hematology     Hybrid Journal   (Followers: 11)
Sensing and Bio-Sensing Research     Open Access  
Sensors     Open Access   (Followers: 14)
Sexual Development     Full-text available via subscription   (Followers: 2)
Sierra Leone Journal of Biomedical Research     Open Access  
Signal Transduction and Targeted Therapy     Open Access  
Signal Transduction Insights     Open Access   (Followers: 2)
Simbiosis : Journal of Biological Sciences     Open Access  
SINET : Ethiopian Journal of Science     Open Access   (Followers: 6)
Small     Hybrid Journal   (Followers: 11)
Small GTPases     Full-text available via subscription   (Followers: 1)
Social and Natural Sciences Journal     Open Access  
Sociobiology     Open Access  
Somatosensory and Motor Research     Hybrid Journal   (Followers: 1)
Source Code for Biology and Medicine     Open Access  
South African Journal of Enology and Viticulture     Open Access  
South African Journal of Science     Open Access   (Followers: 3)
South Asian Journal of Experimental Biology     Open Access  
South Australian Naturalist, The     Full-text available via subscription  
Spatial Vision     Hybrid Journal   (Followers: 2)
Sri Lankan Journal of Biology     Open Access  
Standards in Genomic Sciences     Open Access  
Statistics in Biosciences     Hybrid Journal   (Followers: 3)
Stem Cell and Translational Investigation     Open Access   (Followers: 2)
Stem Cell Biology and Research     Open Access   (Followers: 5)
Stem Cell Discovery     Open Access   (Followers: 4)
Stem Cell Epigenetics     Open Access   (Followers: 3)
Stem Cell Reports     Open Access   (Followers: 9)
Stem Cell Research     Open Access   (Followers: 14)
Stem Cell Reviews and Reports     Hybrid Journal   (Followers: 8)
Stem Cells     Hybrid Journal   (Followers: 7)
Stem Cells and Cloning: Advances and Applications     Open Access   (Followers: 2)
Stem Cells International     Open Access   (Followers: 1)
Steroids     Hybrid Journal  
Studies in Mycology     Open Access   (Followers: 3)
Studies on Neotropical Fauna and Environment     Hybrid Journal   (Followers: 1)
Subterranean Biology     Open Access  
Sugar Tech     Hybrid Journal   (Followers: 2)
Summa Phytopathologica     Open Access  
Sunsari Technical College Journal     Open Access  
Surface Science Reports     Full-text available via subscription   (Followers: 15)
Sustainability : The Journal of Record     Hybrid Journal   (Followers: 6)
Symbiosis     Hybrid Journal   (Followers: 1)
Synthesis Lectures on Biomedical Engineering     Full-text available via subscription  
Synthetic Biology     Full-text available via subscription  
Systematic Biology     Hybrid Journal   (Followers: 13)
Systematics and Biodiversity     Hybrid Journal   (Followers: 10)
Systems and Synthetic Biology     Hybrid Journal   (Followers: 11)
Systems Biology in Reproductive Medicine     Hybrid Journal  
Taprobanica : The Journal of Asian Biodiversity     Open Access  
Taxon     Full-text available via subscription   (Followers: 5)
Telomere and Telomerase     Open Access  
Terrestrial Arthropod Reviews     Hybrid Journal   (Followers: 1)
The Anatomical Record : Advances in Integrative Anatomy and Evolutionary Biology     Hybrid Journal   (Followers: 2)
The Botulinum J.     Hybrid Journal  
The Breast Journal     Hybrid Journal   (Followers: 9)
The Bryologist     Full-text available via subscription   (Followers: 8)
The Cerebellum     Hybrid Journal   (Followers: 2)
The Coleopterists Bulletin     Full-text available via subscription   (Followers: 2)
The Condor     Full-text available via subscription   (Followers: 28)
The Enzymes     Full-text available via subscription   (Followers: 2)
The FASEB Journal     Full-text available via subscription   (Followers: 23)
The Herpetological Journal     Full-text available via subscription   (Followers: 7)
The International Journal of Advanced Manufacturing Technology     Hybrid Journal   (Followers: 6)
The Journal of Technology Transfer     Hybrid Journal   (Followers: 7)
The Knee     Hybrid Journal   (Followers: 14)
The Nucleus     Hybrid Journal   (Followers: 1)
The Physics of Metals and Metallography     Hybrid Journal   (Followers: 16)
The Plant Cell     Full-text available via subscription   (Followers: 26)
The Protein Journal     Hybrid Journal   (Followers: 8)
Theoretical Biology and Medical Modelling     Open Access   (Followers: 1)
Theoretical Population Biology     Hybrid Journal   (Followers: 8)
Tissue and Cell     Hybrid Journal   (Followers: 2)
Tissue Engineering and Regenerative Medicine     Hybrid Journal   (Followers: 10)
Tissue Engineering Part A     Hybrid Journal   (Followers: 10)
Tissue Engineering Part B: Reviews     Hybrid Journal   (Followers: 8)
Tissue Engineering Part C: Methods     Hybrid Journal   (Followers: 8)
Toxicology in Vitro     Hybrid Journal   (Followers: 11)
Traffic     Hybrid Journal   (Followers: 6)
Transactions of the Royal Society of South Australia     Hybrid Journal  
Transcription     Full-text available via subscription   (Followers: 2)
Transgenic Research     Hybrid Journal   (Followers: 3)
Translational Psychiatry     Open Access   (Followers: 10)
Transportation Planning and Technology     Hybrid Journal   (Followers: 8)
Tree Genetics & Genomes     Hybrid Journal   (Followers: 3)
Tree-Ring Research     Full-text available via subscription  
Trees     Hybrid Journal   (Followers: 5)
Trends in Bacteriology     Open Access   (Followers: 3)
Trends in Bioinformatics     Open Access   (Followers: 21)
Trends in Biotechnology     Full-text available via subscription   (Followers: 126)
Trends in Cell Biology     Full-text available via subscription   (Followers: 33)
Trends in Evolutionary Biology     Open Access   (Followers: 13)
Trends in Microbiology     Full-text available via subscription   (Followers: 35)
Trends in Molecular Sciences     Open Access   (Followers: 5)
Trends in Parasitology     Full-text available via subscription   (Followers: 8)
Trends in Plant Science     Full-text available via subscription   (Followers: 26)
Trends in Vector Research and Parasitology     Open Access  
Tropical Freshwater Biology     Full-text available via subscription  
Tumor Biology     Hybrid Journal   (Followers: 3)
Tumor Microenvironment and Therapy     Open Access  
Tunnelling and Underground Space Technology     Hybrid Journal   (Followers: 7)
Turtle and Tortoise Newsletter     Full-text available via subscription   (Followers: 1)
Ukrainian Journal of Ecology     Open Access   (Followers: 1)
Ultrasound in Medicine & Biology     Full-text available via subscription   (Followers: 8)
Uniciencia     Open Access  
Universal Journal of Biomedical Engineering     Open Access  
Unnes Journal of Biology Education     Open Access  
Vakuum in Forschung und Praxis     Hybrid Journal   (Followers: 2)
Vascular Cell     Open Access  
Victorian Naturalist, The     Full-text available via subscription   (Followers: 3)
Virchows Archiv     Hybrid Journal   (Followers: 1)
Virologica Sinica     Hybrid Journal  
Virology Journal     Open Access   (Followers: 6)
Virulence     Full-text available via subscription   (Followers: 1)
Virus Evolution     Open Access   (Followers: 1)
Virus Genes     Hybrid Journal   (Followers: 1)
Virus Research     Hybrid Journal   (Followers: 1)
Visnyk of Dnipropetrovsk University. Biology, ecology     Open Access   (Followers: 2)
Visnyk of Dnipropetrovsk University. Biology, medicine     Open Access  
Walailak Journal of Science and Technology     Open Access  
Web Ecology     Open Access   (Followers: 6)

  First | 1 2 3 4 5 6 7 8 | Last

Journal Cover Journal of Avian Biology
  [SJR: 1.296]   [H-I: 59]   [23 followers]  Follow
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 0908-8857 - ISSN (Online) 1600-048X
   Published by John Wiley and Sons Homepage  [1581 journals]
  • The evolutionary origin of variation in song length and frequency in the
           avian family Cettiidae
    • Authors: Chentao Wei; Trevor D. Price, Jiayu Liu, Per Alström, Yanyun Zhang
      Abstract: Aspects of bird song have been shown to correlate with morphological and ecological features, including beak and body size, and habitat. Here we study evolution of song length and song frequency among 30 species belonging to the Cettiidae. Frequency is negatively correlated with body size, and song length increases with latitude. Although migration distance correlates with latitude, the association of song length with latitude is only present within the non-migratory species, implying the association is not a consequence of migration. We place these correlations in a historical framework to show that the body size-frequency association arose early in the group, but the latitude-song length association is more evolutionarily labile. We suggest that latitudinal correlates of song length may reflect increased importance of sexual selection by female choice.This article is protected by copyright. All rights reserved.
      PubDate: 2017-04-12T04:26:15.186599-05:
      DOI: 10.1111/jav.01366
  • Does habitat specialization shape the evolutionary potential of wild bird
    • Authors: Martinossi-Allibert I; Clavel J, Ducatez S, Le Viol I, Teplitsky C
      Abstract: Because specialist species evolved in more temporally and spatially homogeneous environments than generalist species, they are supposed to experience less fluctuating selection. For this reason, we expect specialists to show lower overall genetic variation as compared to generalists. We also expect populations from specialist species to be smaller and more fragmented, with lower neutral genetic diversity. We tested these hypotheses by investigating patterns of genetic diversity along a habitat specialization gradient in wild birds, based on estimates of heritability, coefficients of variation of additive genetic variance, and heterozygosity available in the literature. We found no significant effect of habitat specialization on any of the quantitative genetic estimators but generalists had higher heterozygosity. This effect was mainly a consequence of the larger population size of generalists. Our results suggest that evolutionary potential does not differ at the population level between generalist and specialist species, but the trend observed in heterozygosity levels and population sizes may explain their difference in susceptibility to extinction.This article is protected by copyright. All rights reserved.
      PubDate: 2017-04-12T04:26:14.172697-05:
      DOI: 10.1111/jav.01011
  • Survivorship across the annual cycle of a migratory passerine, the willow
    • Authors: Eben H. Paxton; Scott L. Durst, Mark K. Sogge, Thomas J. Koronkiewicz, Kristina L. Paxton
      Abstract: Annual survivorship in migratory birds is a product of survival across the different periods of the annual cycle (i.e., breeding, wintering, and migration), and may vary substantially among these periods. Determining which periods have the highest mortality, and thus are potentially limiting a population, is important especially for species of conservation concern. To estimate survival probabilities of the willow flycatcher (Empidonax traillii) in each of the different periods, we combined demographic data from a 10-year breeding season study with that from a 5-year wintering grounds study. Estimates of annual apparent survival for breeding and wintering periods were nearly identical (65-66%), as were estimates of monthly apparent survival for both breeding and wintering stationary periods (98-99%). Because flycatchers spend at least half the year on the wintering grounds, overall apparent survivorship was lower (88%) on the wintering grounds than on the breeding grounds (97%). The migratory period had the highest mortality rate, accounting for 62% of the estimated annual mortality even though it comprises only one quarter or less of the annual cycle. The migratory period in the willow flycatcher and many other neotropical migrants is poorly understood, and further research is needed to identify sources of mortality during this crucial period.This article is protected by copyright. All rights reserved.
      PubDate: 2017-04-12T04:26:12.059012-05:
      DOI: 10.1111/jav.01371
  • Safety first: terrestrial predators drive selection of highly specific
           nesting sites in colonial-breeding birds
    • Authors: Daniel J. D. Natusch; Jessica A. Lyons, Richard Shine
      Abstract: Nesting is a critical yet hazardous life stage for many birds. For colonial-breeding birds, the conspicuousness of the colony to predators suggests immense pressure to select optimal colonial nesting sites. But what drives selection of those sites' As with solitary nesting birds, reducing access by predators may be the single most important factor. If so, knowledge of the predators involved and the attributes of different potential colony sites can allow us to predict the features that make a site especially safe. We examined the attributes of trees used by breeding colonies of metallic starlings (Aplonis metallica) in tropical Australia, and experimentally tested if those attributes prevented nest access by predatory snakes. Our surveys confirmed that tree choice by starling nesting colonies is highly non-random, with all colonies located in tall trees in rainforest clearings, with no low branches and smooth bark. Experimental tests demonstrated that a predatory snake's climbing ability depends upon bark rugosity, and that colony access by snakes depends on tree attributes such as bark rugosity and canopy connectivity. Our study confirms that colonial-nesting starlings select colony sites that provide a safe refuge from predation. Intense predation pressure may have driven the evolution of stringent breeding habitat criteria in many other species of colonial-breeding birds.This article is protected by copyright. All rights reserved.
      PubDate: 2017-04-07T00:45:27.650855-05:
      DOI: 10.1111/jav.01380
  • Altered breeding biology of the European blackbird under artificial light
           at night
    • Authors: Anja Russ; Terézia Lučeničová, Reinhard Klenke
      Abstract: Artificial light at night (LAN) has become a stressor of global extent. Previous work has highlighted the high potential of LAN to interfere with annual and diel rhythms of seasonal organisms as well as to affect interactions at the community level. However, our understanding how LAN induced alterations of activity and breeding cycles affect the reproductive outcome and fitness of the birds is still limited. Here, we focus on the effects of night time illumination on the breeding biology of urban European blackbirds (Turdus merula). Our results indicate that blackbirds prefer illuminated nest sites and advance their date of clutch initiation by 6 days per 1 lux of night time illumination. Furthermore, daily nest survival rates increased with increasing LAN although this effect was most pronounced for the transition from dark to slightly illuminated sites. We suggest that blackbirds breeding under low artificial night light conditions benefit from the LAN-avoidance of their major predators (nocturnal) whereas predominant predators of blackbirds nesting in the city centre are diurnal and are, thus, not affected by LAN. Hence, it seems likely that both direct effects of LAN on the timing of reproduction as well as indirect effects on interspecific interactions might contribute to the observed changes in the breeding biology of European blackbirds.This study emphasizes the diverse ecological effects of the night time illumination which are – in its complexity – still poorly understood.This article is protected by copyright. All rights reserved.
      PubDate: 2017-04-05T05:40:37.511881-05:
      DOI: 10.1111/jav.01210
  • Contributions of feather microstructure to eider down insulation
    • Authors: Liliana D'Alba; Thomas Holm Carlsen, Árni Ásgeirsson, Matthew. D Shawkey, Jón Einar Jónsson
      Abstract: Insulation is an essential component of nest structure that helps provide incubation requirements for birds. Many species of waterfowl breed in high latitudes where rapid heat loss can necessitate a high energetic input from parents and use down feathers to line their nests. Common Eider (Somateria mollissima) nest down has exceptional insulating properties but the microstructural mechanisms behind the feather properties have not been thoroughly examined.Here, we hypothesized that insulating properties of nest down are correlated to down feather (plumule) microstructure. We tested the thermal efficiency (fill power) and cohesion of plumules from nests of two Icelandic colonies of wild Common Eiders and compared them to properties of plumules of wild Greylag Goose (Anser anser). We then used electron microscopy to examine the morphological basis of feather insulating properties. We found that Greylag Goose down has higher fill power (i.e. traps more air) but much lower cohesion (i.e. less prone to stick together) compared to Common Eider down. These differences were related to interspecific variation in feather microstructure. Down cohesion increased with the number of barbule microstructures (prongs) that create strong points of contact among feathers. Eider down feathers also had longer barbules than Greylag Goose down feathers, likely increasing their air-trapping capacity. Feather properties of these two species might reflect the demands of their contrasting evolutionary history. In Greylag Goose, a temperate, terrestrial species, plumule microstructure may optimize heat trapping. In Common Eiders, a diving duck that nests in arctic and subarctic waters, plumule structure may have evolved to maximize cohesion over thermal insulation, which would both reduce buoyancy during their foraging dives and enable nest down to withstand strong arctic winds.This article is protected by copyright. All rights reserved.
      PubDate: 2017-04-05T05:40:36.304586-05:
      DOI: 10.1111/jav.01294
  • Individuality in northern lapwing migration and its link to timing of
    • Authors: Götz Eichhorn; Willem Bil, James W. Fox
      Abstract: We tracked eight adult northern lapwings, Vanellus vanellus, (six females and two males) from a Dutch breeding colony by light-level geolocation year-round, three of them for multiple years. We show that birds breeding virtually next to each other may choose widely separated wintering grounds, stretching from nearby the colony west towards the UK and Ireland, and southwest through France into Iberia and Morocco. However, individual lapwings appeared relatively faithful to a chosen wintering area, and timing of outward and homeward migration can be highly consistent between years. Movements of migratory individuals were usually direct and fast, with some birds covering distances of approximately 2000 km within 2 to 4 days of travel. The two males wintered closest and returned earliest to the breeding colony. The female lapwings returned well before the onset of breeding, spending a pre-laying period of 19 to 54 days in the wider breeding area. Despite the potential for high migration speeds, the duration that birds were absent from the breeding area increased with distance to wintering areas, a pattern which was mainly driven by an earlier outward migration of birds heading for more distant wintering grounds. Moreover, females that overwintered closer to colony bred earlier. A large variation in migration strategies found even within a single breeding colony has likely supported the species’ responsiveness to recent climate change as evidenced by a shortened migration distance and an advanced timing of reproduction in Dutch lapwings since the middle of the 20th century.This article is protected by copyright. All rights reserved.
      PubDate: 2017-04-05T05:40:34.23809-05:0
      DOI: 10.1111/jav.01374
  • Characterising demographic contributions to observed population change in
           a declining migrant bird
    • Authors: Jennifer A. Border; Ian G. Henderson, Ian R. Hartley
      Abstract: Populations of Afro-Palearctic migrant birds have shown severe declines in recent decades. To identify the causes of these declines, accurate measures of both demographic rates (seasonal productivity, apparent survival, immigration) and environmental parameters will allow conservation and research actions to be targeted effectively. We used detailed observations of marked breeding birds from a ‘stronghold’ population of whinchats Saxicola rubetra in England (stable against the declining European trend) to reveal both on-site and external mechanisms that contribute to population change. From field data, a population model was developed based on demographic rates from 2011 to 2014. Observed population trends were compared to the predicted population trends to assess model-accuracy and the influence of outside factors, such as immigration. The sensitivity of the projected population growth rate to relative change in each demographic rate was also explored. Against expectations of high productivity, we identified low seasonal breeding success due to nocturnal predation and low apparent first-year survival, which led to a projected population growth rate (') of 0.818, indicating a declining trend. However, this trend was not reflected in the census counts, suggesting that high immigration was probably responsible for buffering against this decline. Elasticity analysis indicated ' was most sensitive to changes in adult survival but with covariance between demographic rates accounted for, ' was most sensitive to changes in productivity. Our study demonstrates that high quality breeding habitat can buffer against population decline but high immigration and low productivity will expose even such stronghold populations to potential decline or abandonment if either factor is unsustainable. First-year survival also appeared low, however this result is potentially confounded by high natal dispersal. First-year survival and/or dispersal remains a significant knowledge gap that potentially undermines local solutions aimed at counteracting low productivity.This article is protected by copyright. All rights reserved.
      PubDate: 2017-04-05T05:40:32.205494-05:
      DOI: 10.1111/jav.01305
  • Preparation for flight: pre-fledging exercise time is correlated with
           growth and fledging age in burrow-nesting seabirds
    • Authors: Ken Yoda; Tatsuya Shiozaki, Masaki Shirai, Sakiko Matsumoto, Maki Yamamoto
      Abstract: Chicks of many burrow-nesting seabirds are known to repeatedly emerge from their nests (these trips being termed ‘excursions’) and exercise their wings prior to fledging, but this behavior is poorly documented in the literature, and thus the relationship between growth and exercise remains unclear. Here, we used infrared video cameras placed in front of streaked shearwater Calonectris leucomelas nests during the chick-emergence period to examine correlations between chick excursions and parameters known to be important for juvenile survival after fledging. In addition, we also attached acceleration-temperature loggers to several chicks in order to evaluate the relationship between excursion time and time spent exercising the wing muscles (i.e. flapping). Chicks that undertook longer excursions exhibited more rapid increases in wing length and larger body masses at fledging, and also fledged earlier. Correlations between fitness-related parameters and excursion time indicate that excursions during the emergence period might offer insights into the various relationships between growth and behavior and/or the mechanisms underlying offspring survival following fledging.
      PubDate: 2017-03-15T06:40:33.41229-05:0
      DOI: 10.1111/jav.01186
  • Variable drivers of primary versus secondary nesting; density-dependence
           and drought effects on greater sage-grouse
    • Authors: Erik J. Blomberg; Daniel Gibson, Michael T. Atamian, James S. Sedinger
      Abstract: Organisms seek to maximize fitness by balancing reproductive allocations against mortality risk, given selection pressures inherent to the environment. However, environmental conditions are often dynamic and unpredictable, which complicates the ability to achieve such a balance, and may require reproductive adjustments depending on prevailing conditions. We evaluated the effects of density-dependent, density-independent (drought), and individual (age, body condition) factors on nesting decisions of female greater sage-grouse in the American Great Basin. We obtained relocations and recorded reproductive histories from 287 radio-marked females over a period of 10 yr, and applied these data to a multi-state model that estimated probabilities of initiating a first nest (primary nesting rate) or a second nest, given loss of a first (secondary nesting rate). This approach allowed us to evaluate the relative association between nesting rates and covariates while accounting for imperfect detection of nests. Sage-grouse primary and secondary nesting were influenced differently by density dependence and drought. Primary nesting was high and relatively constant among years despite variable drought conditions, but was negatively associated with population size (density dependence). Secondary nesting was lower and more variable compared to primary nesting, was similarly influenced by density-dependence, and was also sensitive to drought conditions. Females known to initiate second nests were in better body condition than females that only initiated first nests, and females of intermediate age had higher primary nesting rates, whereas secondary nesting was unaffected by age. Our results suggest that females were more flexible and responded more readily to changing conditions when allocating resources to second nests. These results are consistent with patterns that have been demonstrated for female allocation to clutch size in this system, and suggest that when conditions are poor second nests reflect a tipping point where reproductive costs (increased mortality) outweigh benefits (offspring reproductive value).
      PubDate: 2017-03-15T06:40:25.501831-05:
      DOI: 10.1111/jav.00988
  • Songbirds are resilient to hurricane disturbed habitats during spring
    • Authors: Emily J. Lain; Theodore J. Zenzal, Frank R. Moore, Wylie C. Barrow, Robert H. Diehl
      Abstract: The Gulf of Mexico is a conspicuous feature of the Neotropical–Nearctic bird migration system. Traveling long distances across ecological barriers comes with considerable risks, and mortality associated with intercontinental migration may be substantial, including that caused by storms or other adverse weather events. However, little, if anything, is known about how migratory birds respond to disturbance-induced changes in stopover habitat. Isolated, forested cheniere habitat along the northern coast of the Gulf of Mexico often concentrate migrants, during weather conditions unfavorable for northward movement or when birds are energetically stressed. We expected hurricane induced degradation of this habitat to negatively affect the abundance, propensity to stopover, and fueling trends of songbirds that stopover in coastal habitat. We used spring banding data collected in coastal Louisiana to compare migrant abundance and fueling trends before (1993–1996 and 1998–2005) and after hurricanes Rita (2006) and Ike (2009). We also characterized changes in vegetative structure before (1995) and after (2010) the hurricanes. The hurricanes caused dramatic changes to the vegetative structure, which likely decreased resources. Surprisingly, abundance, propensity to stopover, and fueling trends of most migrant species were not influenced by hurricane disturbance. Our results suggest that: 1) the function of chenieres as a refuge for migrants after completing a trans-Gulf flight may not have changed despite significant changes to habitat and decreases in resource availability, and 2) that most migrants may be able to cope with habitat disturbance during stopover. The fact that migrants use disturbed habitat points to their conservation value along the northern coast of the Gulf of Mexico.
      PubDate: 2017-03-15T06:35:29.479386-05:
      DOI: 10.1111/jav.01215
  • A comparative study of insect abundance and reproductive success of barn
           swallows Hirundo rustica in two urban habitats
    • Authors: Peter Györkös Teglhøj
      Abstract: Few studies have quantified the relative reproductive success of passerines in urban habitats. I studied food availability and reproductive success of barn swallows Hirundo rustica in two urban habitats during 2012–2015. Barn swallows breeding in the town center experienced lower insect densities than those in the town periphery. Lower food availability resulted in reduced feeding rates per capita, lower nestling body mass, longer nestling periods, longer inter-clutch intervals, fewer first and second brood fledglings and a lower total number of fledglings produced during the breeding season in comparison to barn swallows breeding in the town periphery. I hypothesize that the lower intra-specific competition for nest sites and fitness advantages linked to the solitary breeding in urban habitats balanced the apparent costs of reproduction in more urbanized habitats.
      PubDate: 2017-03-15T06:30:25.785001-05:
      DOI: 10.1111/jav.01086
  • Wing size but not wing shape is related to migratory behavior in a soaring
    • Authors: Maricel Graña Grilli; Sergio A. Lambertucci, Jean-François Therrien, Keith L. Bildstein
      Abstract: Both wing size and wing shape affect the flight abilities of birds. Intra and inter-specific studies have revealed a pattern where high aspect ratio and low wing loading favour migratory behaviour. This, however, have not been studied in soaring migrants. We assessed the relationship between the wing size and shape and the characteristics of the migratory habits of the turkey vulture Cathartes aura, an obligate soaring migrant. We compared wing size and shape with migration strategy among three fully migratory, one partially migratory and one non-migratory (resident) population distributed across the American continent. We calculated the aspect ratio and wing loading using wing tracings to characterize the wing morphology. We used satellite-tracking data from the migratory populations to calculate distance, duration, speed and altitude during migration. Wing loading, but not aspect ratio, differed among the populations, segregating the resident population from the completely migratory ones. Unlike what has been reported in species using flapping flight during migration, the migratory flight parameters of turkey vultures were not related to the aspect ratio. By contrast, wing loading was related to most flight parameters. Birds with lower wing loading flew farther, faster, and higher during their longer journeys. Our results suggest that wing morphology in this soaring species enables lower-cost flight, through low wing-loading, and that differences in the relative sizes of wings may increase extra savings during migration. The possibility that wing shape is influenced by foraging as well as migratory flight is discussed. We conclude that flight efficiency may be improved through different morphological adaptations in birds with different flight mechanisms.
      PubDate: 2017-03-15T06:25:53.488224-05:
      DOI: 10.1111/jav.01220
  • Early arrival is not associated with more extra-pair fertilizations in a
           long-distance migratory bird
    • Authors: Barbara M. Tomotani; Ezra Caglar, Iván de la Hera, A. Christa Mateman, Marcel E. Visser
      Abstract: When assessing the benefits of early arrival date of migratory birds, a hidden and often ignored component of males’ fitness is the higher chance of early-arriving birds to obtain extra-pair fertilizations. Here we investigated how extra-pair paternity might affect the relationship between male arrival date and number of fertilizations in a model study system, the European pied flycatcher Ficedula hypoleuca. For this purpose, we sampled and genotyped breeding pairs, unpaired males and offspring (including embryos from unhatched eggs when possible) of a Dutch pied flycatcher population. Detailed information on arrival date of males, egg laying date of their social mates and nest success was also recorded. Early-arriving males had early-laying females and males with early-laying females had a higher probability of siring extra-pair eggs and obtain more fertilizations. However, male arrival date alone did not correlate with the probability to gain extra-pair paternity and neither to the amount of fertilized eggs. Both early- and late-arriving males had a higher probability of losing paternity in their own nest compared to birds with an intermediate arrival date. Finally, late-arriving males were more likely to remain unpaired but, interestingly, a few of these birds obtained paternity via extra-pair copulations. Because earlier arrival date did not lead to more extra-pair fertilizations and because such relationship seems to be driven mainly by the female's laying date, we conclude that the contribution of extra-pair paternity to the overall fitness benefits of early male arrival date is relatively small.
      PubDate: 2017-03-15T06:25:28.615302-05:
      DOI: 10.1111/jav.01317
  • Breeding synchrony and extrapair paternity in a species with alternative
           reproductive strategies
    • Authors: Melissa Grunst; Andrea S. Grunst, Rusty A. Gonser, Elaina M. Tuttle
      Abstract: Breeding synchrony may affect the tradeoff between pursuing multiple mates and avoiding paternity loss, translating into differences in the rate of extrapair paternity (EPP). However, diverse empirical relationships between breeding synchrony and EPP remain challenging to explain. We examined whether the relationship between breeding synchrony and EPP varied with male morph, age, body size, or breeding density in the white-throated sparrow (Zonotrichia albicollis). In this species, males of two genetically determined morphs pursue alternative mating strategies. Breeding synchrony positively correlated with EPP within polygamous white morph males, which have high rates of EPP and cuckoldry, but was unrelated to EPP within tan morph males, which prioritize mate guarding and paternal care. As previously reported, males that gained EPP were primarily white males. Males gained EPP more often than expected by chance during their mate's fertile period and on neighboring territories. Since extrapair copulation appears primarily male-driven in this species, these results indicate that white males focus extra-pair mating effort during periods of high synchrony and during their mates’ fertile periods, even at the expense of paternity loss within their own nests. Breeding density, male age, and male size did not modify the relationship between breeding synchrony and EPP. However, older white males had higher cuckoldry rates, perhaps reflecting declines in performance associated with senescence. Results suggest that, even within species, mating strategy may modify how breeding synchrony affects rates of EPP, with positive relationships manifest only within subsets of individuals that pursue a strategy of polygyny at the expense of paternity loss.This article is protected by copyright. All rights reserved.
      PubDate: 2017-03-13T05:36:38.799829-05:
      DOI: 10.1111/jav.01375
  • Opportunity costs influence food selection and giving-up density of
           dabbling ducks
    • Authors: Heath M. Hagy; Joshua D. Stafford, Randolph V. Smith, Aaron P. Yetter, Christopher S. Hine, Michelle M. Horath, Christopher J. Whelan
      Abstract: The interaction of animals with their food can yield insights into habitat characteristics, such as perceived predation risk and relative quality. We deployed experimental foraging patches in wetlands used by migrating dabbling ducks Anas spp. in the central Illinois River Valley to estimate variation in seed removal and giving-up density (GUD; i.e. density of food remaining in patches following abandonment) with respect to seed density, seed size, seed depth in the substrate, substrate firmness, perceived predation risk, and an energetic profitability threshold (i.e. critical food density). Seed depth and the density of naturally-occurring seeds outside of experimental plots affected seed removal and GUD in experimental patches more than perceived predation risk, seed density, seed size or substrate firmness. The greatest seed removal and lowest GUDs in experimental patches occurred when food resources in alternative foraging locations outside of plots (i.e. opportunity costs) appeared to be near or below a critical food density (i.e. 119–181 kg ha–1). Giving-up densities varied substantially from a critical food density across a range of food densities in alternative foraging locations suggesting that fixed GUDs should not be used as surrogates for critical food densities in energetic carrying capacity models. Foraging and resting rates in and near experimental foraging patches did not reflect patterns of seed removal and were poor predictors of GUD and foraging habitat quality. Our results demonstrated the usefulness of GUDs as indicators of habitat quality for subsurface, benthic foragers relative to other available foraging patches and suggested that food may be limited for dabbling ducks during spring migration in some years in the midwestern USA.
      PubDate: 2017-03-08T05:36:51.365711-05:
      DOI: 10.1111/jav.01275
  • Effect of haemosporidian infections on host survival and recapture rate in
           the blue tit
    • Authors: Edyta Podmokła; Anna Dubiec, Szymon M. Drobniak, Joanna Sudyka, Adam Krupski, Aneta Arct, Lars Gustafsson, Mariusz Cichoń
      Abstract: Parasites are ubiquitous in the wild and by imposing fitness costs on their hosts they constitute an important selection factor. One of the most common parasites of wild birds are Plasmodium and Haemoproteus, protozoans inhabiting the blood, which cause avian malaria and malaria-like disease, respectively. Although they are expected to cause negative effects in infected individuals, in many cases studies in natural populations failed to detect such effect.Using data from seven breeding seasons (2008–2014), we applied a multistate capture–mark–recapture approach to study the effect of infection with malaria and malaria-like parasites, individual age and sex on the probability of survival and recapture rate in a small passerine, the blue tit Cyanistes caeruleus, inhabiting the island of Gotland, Sweden. We found no effect of infection on survival prospects. However, the recapture rate of infected individuals was higher than that of uninfected ones. Thus, while our data do not support the presence of infection costs in terms of host survival, it suggests that parasites from the genera Plasmodium and Haemoproteus may affect some aspects of host behaviour, which translates into biased estimation of infection frequency at the population level.
      PubDate: 2017-03-08T05:25:40.257616-05:
      DOI: 10.1111/jav.01108
  • Does the house sparrow Passer domesticus represent a global model species
           for egg rejection behavior'
    • Authors: Thomas Manna; Caren Cooper, Shane Baylis, Matthew D. Shawkey, Geoffrey I. N. Waterhouse, Tomas Grim, Mark E. Hauber
      Abstract: Conspecific brood parasitism (CP) is a facultative breeding tactic whereby females lay their eggs in the nests of conspecifics. In some species, potential hosts have evolved the ability to identify and reject foreign eggs from their nest. Previous studies suggest that the ubiquitous house sparrow Passer domesticus in Spain and South Africa employs both CP and egg rejection, while a population in China does not. Given the species’ invasive range expansions, the house sparrow represents a potentially excellent global model system for parasitic egg rejection across variable ecological conditions. We examined the responses of house sparrows to experimental parasitism at three geographically distinct locations (in Israel, North America, and New Zealand) to provide a robust test of how general the findings of the previous studies are. In all three geographic regions egg rejection rates were negligible and not statistically different from background rates of disappearance of control eggs, suggesting that the house sparrow is not a suitable model species for egg rejection experiments on a global scale.
      PubDate: 2017-03-08T05:20:26.622496-05:
      DOI: 10.1111/jav.01193
  • Wintering areas predict age-related breeding phenology in a migratory
           passerine bird
    • Authors: C. López-Calderón; K. A. Hobson, A. Marzal, J. Balbontín, M. Reviriego, S. Magallanes, L. García-Longoria, F. de Lope, Anders P. Møller
      Abstract: Understanding connections between breeding, stopover and wintering grounds for long-distance migratory birds can provide important insight into factors influencing demography and the strength of carry-over effects among various periods of the annual cycle. Using previously described, multi-isotope (δ13C, δ15N, δ2H) feather isoscapes for Africa, we identified the most probable wintering areas for house martins Delichon urbica breeding at Badajoz in southwestern Spain. We identified two most-probable wintering areas differing in isotopic signature in west Africa. We found that the probability to winter in the isotopic cluster two was related to age and sex of individuals. Specifically, experienced males (i.e. two years or older) winter in the isotopic cluster two with a greater probability than experienced females, whereas first-year females winter in the isotopic cluster two with a greater probability than first-year males. In addition, wintering area was correlated with breeding phenology, with individuals wintering in the isotopic cluster two initiating their clutches earlier than those wintering in the isotopic cluster one. For birds wintering in the isotopic cluster two, there was no relationship between age and clutch initiation date. In contrast, young birds wintering in the isotopic cluster one initiated their clutches earlier than experienced birds wintering in this area. There was no significant correlation between wintering area and clutch size or the number of fledglings produced. We hypothesize that the relationship among social status, population density and winter habitat quality should be the most important driver of the carry-over effect we found for this population.
      PubDate: 2017-03-08T05:10:29.143688-05:
      DOI: 10.1111/jav.01070
  • Soaring across continents: decision-making of a soaring migrant under
           changing atmospheric conditions along an entire flyway
    • Authors: Wouter M. G. Vansteelant; Judy Shamoun-Baranes, James McLaren, Jan van Diermen, Willem Bouten
      Abstract: Thermal soaring birds reduce flight-energy costs by alternatingly gaining altitude in thermals and gliding across the earth's surface. To find out how soaring migrants adjust their flight behaviour to dynamic atmospheric conditions across entire migration routes, we combined optimal soaring migration theory with high-resolution GPS tracking data of migrating honey buzzards Pernis apivorus and wind data from a global numerical atmospheric model.We compared measurements of gliding air speeds to predictions based on two distinct behavioural benchmarks for thermal soaring flight. The first being a time-optimal strategy whereby birds alter their gliding air speeds as a function of climb rates to maximize cross-country air speed over a full climb– glide cycle (Vopt). The second a risk-averse energy-efficient strategy at which birds alter their gliding air speed in response to tailwinds/headwinds to maximize the distance travelled in the intended direction during each glide phase (Vbgw).Honey buzzards were gliding on average 2.05 ms– 1 slower than Vopt and 3.42 ms– 1 faster than Vbgw while they increased air speeds with climb rates and reduced air speeds in tailwinds. They adopted flexible flight strategies gliding mostly near Vbgw under poor soaring conditions and closer to Vopt in good soaring conditions.Honey buzzards most adopted a time-optimal strategy when crossing the Sahara, and at the onset of spring migration, where and when they met with the best soaring conditions. The buzzards nevertheless glided slower than Vopt during most of their journeys, probably taking time to navigate, orientate and locate suitable thermals, especially in areas with poor thermal convection.Linking novel tracking techniques with optimal migration models clarifies the way birds balance different tradeoffs during migration.
      PubDate: 2017-03-08T05:06:05.840785-05:
      DOI: 10.1111/jav.01298
  • How birds colonize cities: genetic evidence from a common waterbird, the
           Eurasian coot
    • Authors: Piotr Minias; Radosław Włodarczyk, Alina Minias, Jarosław Dziadek
      Abstract: Much effort has been devoted to identify ecological and life–history traits which facilitate urban colonization by wild avian species, but surprisingly little is known about the population–level mechanisms of urbanization processes. In general, two different patterns of urban colonization have been proposed: 1) the model of independent colonization predicts that birds colonize cities independently in different geographical regions; 2) the model of leapfrog colonization assumes a single colonization event, while additional urban populations are established from the initial urban populations. The aim of this paper was to determine the pattern of urban colonization in a common waterbird, the Eurasian coot Fulica atra. For this purpose, we analysed microsatellite variation in three pairs of urban and rural coot populations from central Poland. We found that a newly–established urban population was genetically more similar to neighbouring rural populations than to long–established urban populations, as indicated by the analysis of fixation index, genetic distance and Bayesian assignment of individuals to genetic clusters. These results are consistent with the model of independent colonization, where neighbouring rural populations are a source of individuals that colonize new urban areas. However, our analysis also showed significant differentiation between long–established urban populations and adjacent rural populations, suggesting that genetic connectivity between two types of habitat decreases with increasing time since urbanization. Our study shows high complexity of urbanization processes in wild animal populations, as well as it underpins utility of molecular tools in studying population–level mechanisms of urbanization.‘This article is protected by copyright. All rights reserved.’
      PubDate: 2017-03-07T09:45:38.670282-05:
      DOI: 10.1111/jav.01334
  • Campylobacter jejuni infection associated with relatively poor condition
           and low survival in a wild bird.
    • Authors: Conor C. Taff; Andrea K. Townsend
      Abstract: Campylobacter jejuni is the most common foodborne pathogen in industrialized countries. Most human infections come from contaminated poultry, but wild birds are also known to harbor C. jejuni. Wild birds are often described as asymptomatic carriers, but this assumption is based on domestic poultry research. We studied the effects of C. jejuni infection on body condition and survival of adult and nestling American Crows (Corvus brachyrhynchos) in Davis, California. Previous work demonstrated that more than half of the crows in this population are infected with C. jejuni and that at least some of the isolates carried by crows are similar to those found in domestic animals and humans. In this study, we compared the body condition of infected and uninfected individuals at the time of capture among adults (n = 44; 52% infected) and nestlings (n = 97; 77% infected). We subsequently monitored these banded individuals for up to 3 years and used mark-recapture survival analysis to estimate relationships between infection status and later survival. We found that adult crows infected with C. jejuni were in poor condition relative to uninfected adults: average body mass of infected birds was 12% lower, whereas average body size did not differ between the two groups. Likewise, apparent survival probability was lower for infected adults. In contrast, nestling body condition, fledging success, and survival did not differ by infection status. This is the first study to document adverse effects of C. jejuni infection in a free-living, wild bird. If these effects are widespread, C. jejuni exposure may be a cause of conservation concern for some species, especially when human activities increase exposure to infections or introduce novel strains to wild bird populations. Our results add to the growing body of work demonstrating hidden long-term costs of seemingly mild infections in wild populations.This article is protected by copyright. All rights reserved.
      PubDate: 2017-03-07T09:45:34.837203-05:
      DOI: 10.1111/jav.01282
  • High fidelity: extra-pair fertilisations in eight Charadrius plover
           species are not associated with parental relatedness or social mating
    • Authors: Kathryn H. Maher; Luke J. Eberhart-Phillips, András Kosztolányi, Natalie dos Remedios, María Cristina Carmona-Isunza, Medardo Cruz-López, Sama Zefania, James St Clair, Monif AlRashidi, Michael A. Weston, Martín A. Serrano-Meneses, Oliver Krüger, Joseph I. Hoffman, Tamás Székely, Terry Burke, Clemens Küpper
      Abstract: Extra-pair paternity is a common reproductive strategy in many bird species. However, it remains unclear why extra-pair paternity occurs and why it varies among species and populations. Plovers (Charadrius spp.) exhibit considerable variation in reproductive behaviour and ecology, making them excellent models to investigate the evolution of social and genetic mating systems. We investigated inter- and intra-specific patterns of extra-pair parentage and evaluated three major hypotheses explaining extra-pair paternity using a comparative approach based on the microsatellite genotypes of 2,049 individuals from 510 plover families sampled from twelve populations that constituted eight species. Extra-pair paternity rates were very low (0 to 4.1% of chicks per population). No evidence was found in support of the sexual conflict or genetic compatibility hypotheses, and there was no seasonal pattern of extra-pair paternity (EPP). The low prevalence of EPP is consistent with a number of alternative hypotheses, including the parental investment hypothesis, which suggests that high contribution to care by males restricts female plovers from engaging in extra-pair copulations. Further studies are needed to critically test the importance of this hypothesis to plover mate choice.This article is protected by copyright. All rights reserved.
      PubDate: 2017-03-07T09:30:39.552035-05:
      DOI: 10.1111/jav.01263
  • An experimental approach to the Brood Reduction Hypothesis in Magellanic
    • Authors: Barrionuevo Melina; Esteban Frere
      Abstract: In many bird species, eggs in a brood hatch within days of each other, leading to a size asymmetry detrimental to younger siblings. Hatching asynchrony is often thought of as an adaptive strategy, and the most widely studied hypothesis in relation to this is the “Brood Reduction Hypothesis”. This hypothesis states that when food resources are unpredictable, hatching asynchrony will allow the adjustment of the brood size maximizing fledging success and benefitting parents. The Magellanic Penguin (Spheniscus magellanicus) is an appropriate species to test this hypothesis because it has a 2-egg clutch that hatches over a 2-day interval with a broad range of variation (-1 to 4 days), it shows facultative brood reduction, and food abundance between breeding seasons is variable. We performed a manipulative study at Isla Quiroga, Argentina, during three breeding seasons (2010-2012) by forcing broods to hatch synchronously (0 days) or asynchronously (2 or 4 days). Years were categorized based on estimated food abundance. Our study provided mixed results because in the low estimated food abundance year asynchronous broods did not have higher nestling survival than synchronous broods, and the second-hatchling in asynchronous broods did not die more often than those in synchronous broods. On the other hand, younger siblings of 4-day asynchronous broods starved earlier than those of synchronous broods, and 2-day asynchronous broods fledged heavier young than synchronous broods. Asynchronous hatching would seem to benefit reproduction in this species, not with respect to survival, but in terms of the advantages it can accord to nestlings and, in terms of lower costs, for parents raising nestlings.This article is protected by copyright. All rights reserved.
      PubDate: 2017-03-07T09:30:35.025814-05:
      DOI: 10.1111/jav.01200
  • Evaluating the reliability of species distribution models with an indirect
           measure of bird reproductive performance
    • Authors: Olatz Aizpurua; Lisette Cantú-Salazar, Gilles San Martin, Francesc Sardà-Palomera, Gabriel Gargallo, Sergi Herrando, Lluís Brotons, Nicolas Titeux
      Abstract: Measures of fitness such as reproductive performance are considered reliable indicators of habitat quality for a species. Such measures are, however, only available in a restricted number of sites, which prevents them from being used to quantify habitat quality across landscapes or regions. Alternatively, species presence records can be used along with environmental variables to build models that predict the distribution of species across larger spatial extents. Model predictions are often used for management purposes as they are assumed to describe the quality of the habitats to support a species. Yet, given that species are often present both in optimal and suboptimal areas, the use of data collected during the breeding season to build these models may potentially result in misleading predictions of habitat quality for the reproduction of the species, with potentially significant conservation consequences. In this study we analysed the relationship between fitness parameters informing on habitat quality for reproduction and predictions of species distribution models at multiple spatial scales using two independent sets of data. For 19 passerine bird species, we compared an indirect measure of reproductive performance (ratio of juveniles-to-adults) – obtained from Constant Effort Sites (CES) mist-netting data in Catalonia – with the predictions of models based on bird presence records collected during the Catalan Breeding Bird Atlas (CBBA). A positive relationship between the predictions derived from species distribution models and the reproductive performance of the species was found for half of the species at one or more spatial scales. This result suggests that species distribution models may help to predict habitat quality for some species over some extents. However, caution is needed as this is not consistent for all species at all scales. Further work based on species- and scale-specific approaches is now required to understand in which situations species distribution models provide predictions that are in line with reproductive performance.This article is protected by copyright. All rights reserved.
      PubDate: 2017-03-07T09:30:27.248048-05:
      DOI: 10.1111/jav.01218
  • The Long Shadow of Senescence: Age Impacts Survival and Territory Defense
           in Loons
    • Authors: Walter H. Piper; Kristin M. Brunk, Joel A. Flory, Michael W. Meyer
      Abstract: Senescence, increased mortality that occurs among animals of advanced age, impacts behavior and ecology in many avian species. We investigated actuarial, reproductive, and behavioral senescence using capture, marking, and resighting data from a 26-year study of common loons (Gavia immer). Territorial residents of both sexes exhibited high annual survival (0.94) until their mid 20s, at which point survival fell to 0.76 and 0.77 in males and females, respectively. Sexual symmetry in actuarial senescence is somewhat surprising in this species, because males make a substantially greater investment in territory defense and chick-rearing and because males engage in lethal contests for territory ownership. Survival of displaced breeders (0.80) was lower than that of territorial residents in both young and old individuals. Old males and females also experienced slightly higher annual probability of eviction (0.16 for males; 0.17 for females) than prime-aged breeders (0.13 for both sexes), indicating senescence in territory defense. Prime-aged males reclaimed territories at a high rate (0.49), in contrast to females of the same age (0.33). However, old males resettled with success (0.35) similar to old females (0.31), suggesting that males decline in competitive ability as they age. Nonetheless males, but not females, showed an apparent increase in breeding success over the entire lifetime, a possible indication that very old males make a terminal investment in reproductive output at the cost of survival.This article is protected by copyright. All rights reserved.
      PubDate: 2017-03-04T00:40:27.600463-05:
      DOI: 10.1111/jav.01393
  • Intrinsic factors drive spatial genetic variation in a highly vagile
           species, the wedge-tailed eagle (Aquila audax), in Tasmania
    • Authors: Christopher P. Kozakiewicz; Scott Carver, Jeremy J. Austin, Jill M. Shephard, Christopher P. Burridge
      Abstract: Knowledge of dispersal in a species, both its quantity and the factors influencing it, are crucial for our understanding of ecology and evolution, and for species conservation. Here we quantified and formally assessed the potential contribution of extrinsic factors on individual dispersal in the threatened Tasmanian population of wedge-tailed eagle, Aquila audax. As successful breeding by these individuals appears strongly related to habitat, we tested the effect of landscape around sampling sites on genetic diversity and spatial genetic variation, as these are influenced by patterns of dispersal. Similarly, we also tested whether habitat intervening sampling sites could explain spatial genetic variation. Twenty microsatellites were scored, but only a small proportion of spatial genetic variation (4.6%) could be explained by extrinsic factors, namely habitat suitability and elevation between sites. However, significant clinal genetic variation was evident across Tasmania, which we explain by intrinsic factors, likely high natal philopatry and occasional long-distance dispersal. This study demonstrates that spatial genetic variation can be detected in highly vagile species at spatial scales that are small relative to putative dispersal ability, although here there was no substantial relationship with landscape factors tested.This article is protected by copyright. All rights reserved.
      PubDate: 2017-02-28T10:20:23.222025-05:
      DOI: 10.1111/jav.01326
  • Reduced dietary conservatism in a wild bird in the presence of
           intraspecific competition
    • Authors: Keith McMahon; Nicola Marples
      Abstract: The presence of intraspecific competitors can increase foraging costs through exploitation of resources. Optimal foraging theory suggests that when the cost of pursuing one food type increases, alternative resources should be accepted. Accepting novel foods readily might put a competitor at an advantage over its more conservative rivals in the race for sufficient sustenance, but also opens it to the danger of poisoning by chemically protected food. Dietary conservatism is a foraging behaviour characterised by a prolonged avoidance of novel foods, long after neophobia (initial fear of novel objects) has been overcome, and so might be seen as a disadvantage to foragers in a competitive situation. There are two stable foraging strategies found within forager populations: 1) adventurous consumers (AC) which rapidly accept novel foods and 2) foragers showing dietary conservatism (DC). The expression of these two strategies may also vary with environmental conditions. The aim of this study was to investigate the effect of intraspecific competition on the levels of dietary conservatism displayed among wild caught blue tits Cyanistes caeruleus. Blue tits were offered items of both novel and familiar foods under two conditions: with a competitor and without. Our results showed that individuals who experienced competition incorporated the novel items into their diet faster than those who did not experience competition. This study demonstrates, for the first time, the degree of plasticity in the expression of the DC trait using wild birds in laboratory conditions. This plasticity represents a significant adaptation to reduce the costs of foraging conservatively when novel alternative resources should be accepted.
      PubDate: 2017-02-21T06:40:46.14523-05:0
      DOI: 10.1111/jav.01135
  • Migration strategies and annual space-use in an Afro-Palaearctic aerial
           insectivore – the European nightjar Caprimulgus europaeus
    • Authors: Gabriel Norevik; Susanne Åkesson, Anders Hedenström
      Abstract: Obligate insectivorous birds breeding in high latitudes travel thousands of kilometres during annual movements to track the local seasonal peaks of food abundance in a continuously fluctuating resource landscape. Avian migrants use an array of strategies when conducting these movements depending on e.g. morphology, life history traits and environmental factors encountered en route. Here we used geolocators to derive data on the annual space-use, temporal pattern and migratory strategies in an Afro-Palaearctic aerial insectivorous bird species – the European nightjar Caprimulgus europaeus. More specifically, we aimed to test a set of hypothesises pertaining to the migration of a population of nightjars breeding in south-eastern Sweden. We found that the birds wintered across the central and western parts of the southern tropical Africa almost entirely outside the currently described wintering range of the species. The nightjars performed a narrow loop migration across Sahara, with spring Sahel stopovers significantly to the west of autumn stops indicative to an adaptive response to winds during migration. To our surprise, the migration speed was faster in the autumn (119 km d− 1) than in the spring (99 km d− 1), possibly due to the prevailing wind regimes over the Sahara. The estimated flight fraction in both autumn (14%) and spring (12%) was almost exactly as the theoretically predicted 1:7 time relationship between flights and stopovers for small birds. The temporal patterns within the annual cycle indicate that individuals follow alternative spatiotemporal schedules that converge towards the breeding season. The positive relationship between the spatially and temporally distant winter departure and breeding arrival suggests that individuals´ temporal fine-tuning to breeding may be constrained, leading to potential negative fitness consequences.
      PubDate: 2017-02-21T06:36:27.607376-05:
      DOI: 10.1111/jav.01071
  • Evaluating interspecific niche overlaps in environmental and geographic
           spaces to assess the value of umbrella species
    • Authors: Yoan Fourcade; Aurélien G. Besnard, Jean Secondi
      Abstract: The concept of umbrella species assumes that concentrating resources on the protection of a single species contributes to the conservation of a suite of species and ecological processes belonging to the same ecosystem. The environmental requirements and geographical distribution of the umbrella species should thus overlap those of the group of targeted species. In western France, the conservation of several large grassland floodplains relies on agri-environmental schemes targeting one single bird species, the corncrake Crex crex. It is considered as an umbrella species but no real assessment of its effectiveness has been carried out so far. We used a two-step methodology to assess the potential of the corncrake to act as an umbrella species by estimating niche overlap in the environmental and geographic space between the main ground-nesting species of the bird community in these grasslands, including the corncrake and four passerines. The five species showed substantial differences in their ecological niches so that their distributions did not perfectly overlap. Overlaps in predicted distributions between pairs of species depended on the threshold used to convert suitability to binary maps. Moreover, the number of species that could be protected by a candidate umbrella species was affected by the overlap criterion of success. Although the corncrake may be used as an umbrella species, it would be outperformed by several passerine species. Our study highlights the potential of using niche overlap to select umbrella species. It also reveals the importance of analysing the sensitivity of outputs when changing thresholds and overlap criteria.
      PubDate: 2017-02-21T06:31:04.1398-05:00
      DOI: 10.1111/jav.01153
  • Age-related prenatal maternal effects and postnatal breeding experience
           have different influences on nestling development in an altricial
    • Authors: Pierre-Paul Bitton; Russell D. Dawson
      Abstract: Reproductive success and nestling performance are related to the age of parents across several vertebrate taxa. However, because breeding experience and prenatal maternal investment in reproduction often covary, the source of these age-related differences can be difficult to determine. In this study, we evaluated the influence of prenatal maternal effects and postnatal breeding experience on the performance of nestling tree swallows Tachycineta bicolor by conducting a carefully controlled partial cross-fostering experiment. We swapped half-broods of nestlings between the nest of a young first-time breeding female and the nest of a female known to have previously raised and fledged young. Our manipulation did not influence the within-brood nestling hierarchies, and controlled for the effects of egg laying order. We found that nestlings of older females were heavier just prior to fledging regardless of the breeding experience of the attending female. In addition, fledglings raised by experienced females grew their flight feathers faster, and had greater probability of fledging. Our study demonstrates that prenatal investment in reproduction by older females can have long-term consequences on nestling mass, and suggests limited potential for compensatory mass gains prior to fledging. Because our analyses controlled for feeding rates, our results also suggest that foraging quantity and quality are not the only benefits nestlings gain by being raised by an experienced female.
      PubDate: 2017-02-21T06:05:50.130226-05:
      DOI: 10.1111/jav.01202
  • Parent birds assess nest predation risk: influence of cavity condition and
           avian nest predator activity
    • Authors: Jongmin Yoon; Jung-Shim Jung, Eun-Jin Joo, Byung-Su Kim, Shi-Ryong Park
      Abstract: Skutch hypothesized that nest predators visually assess parental activities to locate a prey nest, whereas parents modify fitness-related traits to reduce the probability of nest predation. We examined how cavity condition and parental activity interact with avian nest predators to shape the nest success of two coexisting parid species, marsh tits Poecile palustris and oriental tits Parus minor, breeding in nest-boxes during the incubation period. Nest-boxes were manipulated to create a prolonged risk of nest predation (entrance diameter 2.6 cm control vs 5.5 cm treatment) soon after clutch completion. To measure changes in parental behavior, we also simultaneously simulated a pulsed risk of nest predation, using sound playbacks of a coexisting control bird and an avian nest predator. We found that the parent tits merely responded the pulsed risk, presumably due to an environment with high avian nest predator encounters, compared to the prolonged risk. Instead, both species spent more time on vigilance at the nest, only under prolonged risk conditions. The activity of corvids near the nest-box was higher in the marsh tit than that in oriental tits. This activity was also higher in the treatment nest box than that in the control nest-box. Nest predation during the incubation period was higher in marsh tits than in oriental tits, presumably due to higher and more plastic vigilance in oriental tits, compared to marsh tits. Our results highlight that the differences in cavity condition and parental activities at the nests of two coexisting non-excavators may contribute to differential nest predation by attracting avian nest predators.
      PubDate: 2017-02-21T05:56:00.687923-05:
      DOI: 10.1111/jav.00787
  • Interisland gene flow among populations of the buff-banded rail (Aves:
           Rallidae) and its implications for insular endemism in Oceania
    • Authors: Juan C. Garcia-R; Leo Joseph, Greg Adcock, Julian Reid, Steven A. Trewick
      Abstract: Studies of fragmented habitat, such as island archipelagos, provide insights into the microevolutionary processes that drive early stages of diversification. Here, we examined genetic variation and gene flow among populations of the widespread buff-banded rail Gallirallus philippensis in Oceania to understand the factors that promote speciation associated within this bird lineage. We analysed mtDNA Control Region sequences and six microsatellite loci from a total of 152 individuals of buff-banded rail on islands and continental areas. We used a phylogeographic model-testing approach and a structured spatial design ranging from within to among archipelagoes in the south Pacific. Buff-banded rail populations in the Philippines archipelago and nearby Palau and Wallacea had high genetic diversity while those in geographically distant Australia showed lower variation. Other archipelagos sampled were found to have less genetic diversity and included haplotypes closely related to Wallacea (Bismarck, Vanuatu, New Caledonia) or Australia (New Zealand, Samoa, Fiji, Cocos Islands). Nucleotide diversity and allele frequency declined with degree of geographic isolation but haplotype diversity remained more even. However, both nucleotide and haplotype diversities were positively correlated with land area. Microsatellite data for a subset of locations showed moderate to high genetic differentiation and significant pairwise FST despite a relatively high migration rate. Our results are mostly consistent with a model of abrupt genetic changes due to founder events with multiple dispersals into Australia from Wallacea and Bismarck. Australia has probably been the source of birds for islands in the Pacific. This is shown by decreasing genetic diversity and growing genetic differentiation when distances separating populations increased from Australia. A history of range expansion and divergent natural selection may help explain the existence of numerous sympatric Gallirallus island endemics.
      PubDate: 2017-02-21T05:50:58.793116-05:
      DOI: 10.1111/jav.01201
  • First genetic assessment of the level of endemism in the avifauna of the
           Central Sierras in southern South America
    • Authors: Belén Bukowski; Pablo D. Lavinia, Natalia Trujillo-Arias, Cecilia Kopuchian, Pablo L. Tubaro, Darío A. Lijtmaer
      Abstract: The Andes constitute one of the main factors that have promoted diversification in the Neotropics. However, the role of other highland regions in the southern cone of South America has been barely studied. We analyzed the level of endemism in the avifauna of the Central Sierras in Córdoba, a high region in central Argentina, to evaluate the effect of its geographic isolation from the Andes. There are 11 species with endemic subspecies in this region, all of them described based only on differences in morphology (mainly plumage color) with no genetic evidence. We performed the first genetic analyses of seven of these species using mitochondrial DNA obtained from fresh tissue and toe pad samples. Our results show that for three of these species, Catamenia inornata, Phrygilus unicolor and Cinclodes atacamensis, the population in the Central Sierras is clearly differentiated from those of other regions, and the first two of them also show divergence among Andean subspecies. In the remaining species we found a varying degree of differentiation, ranging from a small divergence in Muscisaxicola rufivertex to the presence of different haplotypes but with an apparent lack of phylogeographic structure in Phrygilus plebejus and Sturnella loyca (being the latter the only species with a continuous distribution between the Central Sierras and the Andes) to haplotype sharing in Asthenes modesta. While further analyses including additional markers, morphological characters and vocalizations are needed, our results show that some of the species that have disjunct distributions, with a population in the Central Sierras isolated geographically from the Andes, possess distinct genetic lineages in the Central Sierras that suggest an evolutionary isolation from other populations. These findings highlight the importance of montane regions in general, and the Central Sierras in particular, as drivers of diversification in the Neotropics.
      PubDate: 2017-02-21T05:41:34.39186-05:0
      DOI: 10.1111/jav.01087
  • Experimental feeding regime influences urban bird disease dynamics
    • Authors: Josie A. Galbraith; Margaret C. Stanley, Darryl N. Jones, Jacqueline R. Beggs
      Abstract: Wild bird feeding often results in high densities of birds, potentially facilitating transmission of disease. Wild birds are major reservoirs of many zoonotic diseases, and although a number of avian disease outbreaks have been linked to bird feeders, urban bird-feeding and its role in disease systems remains poorly studied. We examined the impacts of typical supplementary feeding practices on the health status of feeder-visiting birds at experimental feeding stations in an urban area of New Zealand. Over an 18-month period, we screened birds captured at feeding and non-feeding properties for three pathogens and four groups of parasites to determine whether feeding altered disease dynamics. We also assessed body condition. All pathogens and parasites were detected in at least one garden bird species. Feeding stations tested positive for Salmonella enterica Typhimurium on ∼7% of occasions, confirming that structures used in feeding are a potential transmission pathway. Feeding influenced some parasite infection parameters; these effects varied among host species. In silvereyes Zosterops lateralis, helminth prevalence and abundance were lower at feeding properties compared to non-feeding properties. In contrast, Eurasian blackbirds Turdus merula at feeding properties had a higher abundance of helminths. House sparrows Passer domesticus at feeding properties had a higher abundance of feather lice. Furthermore, our feeding regime significantly affected body condition in house sparrow and silvereye, though no associations between parasite parameters and body condition indices were found. Our results demonstrate that feeding practices can have varied effects on avian health, including no observable effects for some disease agents in some host species. Disease risks are present, however, thus understanding and reducing these risks should be a key goal for all stakeholders to protect birds that use feeders and other wildlife.
      PubDate: 2017-02-21T05:10:57.589064-05:
      DOI: 10.1111/jav.01076
  • Divergence and gene flow in the globally distributed blue-winged ducks
    • Authors: Joel T. Nelson; Robert E. Wilson, Kevin G. McCracken, Graeme S. Cumming, Leo Joseph, Patrick-Jean Guay, Jeffrey L. Peters
      Abstract: The ability to disperse over long distances can result in a high propensity for colonizing new geographic regions, including uninhabited continents, and lead to lineage diversification via allopatric speciation. However, high vagility can also result in gene flow between otherwise allopatric populations, and in some cases, parapatric or divergence-with-gene-flow models might be more applicable to widely distributed lineages. Here, we use five nuclear introns and the mitochondrial control region along with Bayesian models of isolation with migration to examine divergence, gene flow, and phylogenetic relationships within a cosmopolitan lineage comprising six species, the blue-winged ducks (genus Anas), which inhabit all continents except Antarctica. We found two primary sub-lineages, the globally-distributed shoveler group and the New World blue-winged/cinnamon teal group. The blue-winged/cinnamon sub-lineage is composed of sister taxa from North America and South America, and taxa with parapatric distributions are characterized by low to moderate levels of gene flow. In contrast, our data support strict allopatry for most comparisons within the shovelers. However, we found evidence of gene flow from the migratory, Holarctic northern shoveler A. clypeata and the more sedentary, African Cape shoveler A. smithii into the Australasian shoveler A. rhynchotis, although we could not reject strict allopatry. Given the diverse mechanisms of speciation within this complex, the shovelers and blue-winged/cinnamon teals can serve as an effective model system for examining how the genome diverges under different evolutionary processes and how genetic variation is partitioned among highly dispersive taxa.
      PubDate: 2017-02-21T04:45:41.634355-05:
      DOI: 10.1111/jav.00998
  • On the use of heterospecific information for nest site selection in birds
    • Authors: Tore Slagsvold; Karen L. Wiebe
      PubDate: 2017-02-20T10:00:24.40835-05:0
      DOI: 10.1111/jav.01398
  • Variability in stable isotopes of snowy owl feathers and contribution of
           marine resources to their winter diet
    • Authors: Audrey Robillard; Gilles Gauthier, Jean-François Therrien, Guy Fitzgerald, Jennifer F. Provencher, Joël Bêty
      Abstract: The snowy owl is an elusive arctic predator known for its nomadic behaviour. Satellite tracking has revealed that some adult snowy owls could make an extensive use of the marine environment during the non-breeding season. However, the relative contribution of marine resources to their diet is unknown. Stable isotope analyses can be useful to document the diet of mobile animals during periods of the year when individuals are less accessible. This study aimed to assess variation in isotopic values (δ13C and δ15N) of various feather types, and the usefulness of feathers to determine the contribution of the marine environment to the winter diet of snowy owls captured in summer. We sampled feathers coming from 6 body regions of 18 breeding females at two sites in the eastern Canadian Arctic in 2013 and 2014. Prior to analyses, diet-tissue discrimination factors of snowy owl feathers were established in captivity. Variability in isotopic values among feather types was relatively low and pairwise correlations in isotopic values between feathers on the same individual were variable and often low, which suggests differences in the diet at the time when various feathers were synthesized. Diet reconstruction models detected a contribution of marine sources to snowy owl feathers ranging from 4% to 19% among feather types. However, the marine contribution was highly variable when single feathers were examined within individuals, ranging from 3% to 71%. This indicated that no single feather type could be used alone to reliably infer the contribution of marine resources to the winter diet of owls, possibly due to a high variability in the timing and sequence of molt. For asynchronous molters like snowy owls, we recommend sampling multiple feathers from various body regions, excluding wing feathers, to investigate winter diet or habitat use.This article is protected by copyright. All rights reserved.
      PubDate: 2017-02-16T04:31:03.056969-05:
      DOI: 10.1111/jav.01257
  • The evolution of feather coloration and song in Old World orioles (genus
    • Authors: Beata Matysioková; Nicholas Friedman, Lucia Turčoková, Vladimír Remeš
      Abstract: What is the tempo and mode of evolution – how fast and in what pattern do traits evolve – is a major question of evolutionary biology. Here we studied patterns of evolutionary change in visual and acoustic signals in Old World orioles. Since producing multiple signals may be costly, we also tested whether there was an evolutionary trade-off between the elaboration of those two types of signals. We studied 30 Oriolus taxa using comparative methods and a recent molecular phylogeny. Morphology and plumage hue evolved comparatively slowly, whereas song evolved rapidly. Among individual feather patches, the evolutionary rate of color was slowest in primaries, which are critical for flapping flight, and fastest in patches exposed to observers (mantle and breast). Thus, primaries seem to be under functional constraint while the evolution of visually exposed patches is perhaps shaped by sexual selection. Song evolution was comparatively fast, but also attracted to a single optimum. This may be due to selection for signal efficacy, because all orioles inhabit similar forested habitats. Only color diversity was best fit by a speciational model: the biggest changes in coloration were concentrated at speciation events, thus perhaps linked to the evolution of species recognition. Our analysis did not reveal any evolutionary trade-off between acoustic and visual signals, suggesting that the elaboration of visual and acoustic signals in the Old World orioles evolved independently. Our study shows that patterns of evolutionary change may be surprisingly complex even within a single clade of birds and thus further studies are needed to identify general patterns of signal macroevolution.This article is protected by copyright. All rights reserved.
      PubDate: 2017-02-14T04:40:41.571179-05:
      DOI: 10.1111/jav.01175
  • Cohabitation with farm animals rather than breeding effort increases the
           infection with feather-associated bacteria in the barn swallow Hirundo
    • Authors: Attila Fülöp; Csongor I. Vágási, Péter L. Pap
      Abstract: Feather-associated bacteria are widespread inhabitants of avian plumage. However, the determinants of the between-individual variation in plumage bacterial loads are less well understood. Infection intensities can be determined by ecological factors, such as breeding habitat, and can be actively regulated by hosts via preening. Preening, yet, is a resource intensive activity, and thus might be traded-off against reproductive investment in breeding birds. Here, we studied barn swallows Hirundo rustica to assess the bacterial cost of reproduction in relation to nesting site micro-habitats. Barn swallows prefer to breed in the company of large-sized farm animals, although the presence of mammalian livestock in barns assures a warm and humid micro-climate that favours bacterial proliferation. Thus, we experimentally manipulated brood sizes of birds breeding in barns with, or without, farm animals and measured total cultivable bacteria (TCB) and feather-degrading bacteria (FDB) from the plumage. We found that the abundance of feather-associated bacteria (i.e. both TCB and FDB) in females, but not males, breeding in barns with livestock were significantly higher than in conspecifics breeding in empty barns. Plumage bacterial loads, however, were not affected by brood size manipulations in either sex. In addition, we report a negative relationship between both TCB and FDB and hatching date in females, and several sex and seasonal differences in plumage bacterial abundances. Our study is the first to show that breeding micro-habitat (i.e. livestock co-tenancy) has consequences for the abundance of feather-associated bacteria.This article is protected by copyright. All rights reserved.
      PubDate: 2017-02-14T04:40:35.833897-05:
      DOI: 10.1111/jav.01262
  • Life history patterns, individual heterogeneity, and density dependence in
           breeding common goldeneyes of the northern boreal forest
    • Authors: Abigail J. Lawson; James S. Sedinger, Eric J. Taylor
      Abstract: Life history patterns and their associated tradeoffs influence population dynamics, as they determine how individuals allocate resources among competing demographic traits. Here we examined life history strategies in common goldeneyes Bucephala clangula (hereafter goldeneye), a cavity-nesting sea duck, in the northern boreal forest of interior Alaska, USA. We used multistate capture–mark–recapture models to estimate adult survival, breeding probability, first-year survival, and recruitment probability using a long-term nest box study (1997–2010). We detected annual variation in adult survival, which varied from 0.74 ± 0.12 (SE) to 0.93 ± 0.06. In contrast, breeding probability remained relatively high and invariant (0.84 ± 0.11) and was positively related to individual nest success the year prior. Nonbreeding individuals in one year were more likely to remain a nonbreeder, than attempt to breed the following year. First-year survival decreased with smaller residual duckling mass and larger brood sizes. Probability of recruitment into the breeding population conditioned on survival was constant during the study (0.96 ± 0.06), and did not vary among ages 2–5 yr-old. Overall, goldeneyes exhibited high, but somewhat variable, adult survival, and high breeding and recruitment probabilities, which is consistent with observed patterns in bet-hedging species that breed annually in high quality breeding environments, but whose reproductive output is often influenced by stochastic events. Demographic estimates from this study are among the first for goldeneyes within Alaska. Life history patterns are known to vary geographically, therefore, we recommend further examination of life history patterns within the distribution of goldeneyes.
      PubDate: 2017-02-13T09:00:27.815738-05:
      DOI: 10.1111/jav.00975
  • Context-dependent effects of radio transmitter attachment on a small
    • Authors: Lysanne Snijders; Lydia E. Nieuwe Weme, Piet de Goede, James L. Savage, Kees van Oers, Marc Naguib
      Abstract: Biotelemetry devices provide unprecedented insights into the spatial behaviour and ecology of many animals. Quantifying the potential effects of attaching such devices to animals is essential, but certain effects may appear only in specific or particularly stressful contexts. Here we analyse the effects of radio transmitter attachment on great tits Parus major tagged over three environmentally dissimilar years, as part of a project studying social- and communication networks. When we radio-tagged birds before breeding, only those tagged in the coldest spring tended to be less likely to breed than control birds. Breeding probability was independent of relative transmitter weight (between 5 and 8% bodyweight). When we radio-tagged both parents during nestling provisioning (transmitter weight between 6 and 8%), tagged parents were more likely than control parents to desert their brood in two out of three years, while in the other year no tagged parents deserted. Tagged parents provisioning larger broods were most likely to desert, especially during lower average temperatures. Video analyses did not reveal any transmitter effects on provisioning behaviour of parents in the year with no desertion. We conclude that radio tagging before breeding did not lead to negative effects, regardless of transmitter weight, but that decisions about radio-tagging both parents during nestling provisioning need to be made with exceptional care, taking both environmental context and transmitter weight into account. Reporting results from long-term radio-tracking studies comprising several environmentally variable years is crucial to understand and predict potential transmitter effects and maximise the tremendous potential of biotelemetry.
      PubDate: 2017-02-13T08:55:25.188318-05:
      DOI: 10.1111/jav.01148
  • Modelling avian growth with the Unified-Richards: as exemplified by
           wader-chick growth
    • Authors: Kathleen M. C. Tjørve; Even Tjørve
      Abstract: Postnatal growth in birds is traditionally modelled by fitting three-parameter models, namely the logistic, the Gompertz, or the von Bertalanffy models. The purpose of this paper is to address the utility of the Unified-Richards (U-Richards) model. We draw attention to two forms of the U-Richards and lay down a set of recommendations for the analysis of bird growth, in order to make this model and the methods more accessible. We examine the behaviour of the four parameters in each model form and the four derived measurements, and we show that all are easy to interpret, and that each parameter controls a single curve characteristic. The two parameters that control the inflection point, enable us to compare its placement in two dimensions, 1) inflection value (mass or length at inflection) and 2) inflection time (time since hatching), between data sets (e.g. between biometrics or between species). We also show how the parameter controlling growth rate directly presents us with the relative growth rate at inflection, and we demonstrate how one can compare growth rates across data sets. The three traditional models, where the inflection value is fixed (to a specific percentage of the upper asymptote), provide incompatible growth-rate coefficients. One of the two forms of the U-Richards model makes it possible to fix not only the upper asymptote (adult value), but also the intersection with the y-axis (hatching value). Fitting the new model forms to data validates the usefulness of interpreting the inflection placement in addition to the growth rate. It also illustrated the advantages and limitations of constraining the upper asymptote (adult value) and the y-axis intersection (hatching value) to fixed values. We show that the U-Richards model can successfully replace some of the commonly used growth models, and we advocate replacing these with the U-Richards when modelling bird growth.
      PubDate: 2017-02-13T08:40:44.89927-05:0
      DOI: 10.1111/jav.00992
  • Habitat suitability and the constraints of migration in New World warblers
    • Authors: David P. L. Toews
      Abstract: Identifying the factors that influence geographic range limits can illustrate the various ecological, physiological, and evolutionary constraints imposed on a species. The range limits of migratory birds are particularly challenging to study as they occur in disjunct regions at different times of the year, which can impose different constraints. Travel between breeding and wintering regions poses a significant energetic and navigational challenge to birds, although it is not clear how these movements influence breeding dispersal and range expansion. Here I ask whether the possible costs of migration limit the breeding ranges of wood warblers, a group of birds with an extensive history of ecological and evolutionary studies. I used occurrence records for multiple wood warbler species, breeding primarily in the boreal forest of North America, to generate environmental niche models. I tested for over-prediction of habitat suitability into the western boreal forest, where most these species do not have occurrence records but where there is presumably suitable habitat. I found that some of these vagile taxa, primarily found east of the Rocky Mountains, also have predicted habitat suitability that extends into the north and west, where they have little to no occurrence records. I discuss several possible explanations for this discordance. In particular, the patterns are consistent with the costs of a long-distance migration limiting the benefits of range expansion, as migration may become too onerous as the distance between breeding and wintering areas increases. These results speak to the process of niche filling more generally and call attention to an under-appreciated explanation for why migratory species may not fully occupy their fundamental niche.This article is protected by copyright. All rights reserved.
      PubDate: 2017-02-10T05:50:52.183644-05:
      DOI: 10.1111/jav.01157
  • Population differentiation in whiskered auklets (Aethia pygmaea): do
           diurnal and nocturnal colonies differ in genetics, morphometry and
    • Authors: Olesya S. Pshenichnikova; Anna V. Klenova, Pavel A. Sorokin, Nikolay B. Konyukhov, Alexander V. Andreev, Sergei P. Kharitonov, Victor A. Zubakin, Yuri B. Artukhin, Carley R. Schacter
      Abstract: Despite a great number of empirical studies, the mechanisms of population differentiation and the factors that influence this process, particularly in seabirds, remain insufficiently understood. Here we analyzed population structure in the whiskered auklet (Aethia pygmaea), a previously poorly studied alcid species with unusual differentiation in colony attendance rhythms (i.e. diurnal in the Sea of Okhotsk vs. nocturnal in the Bering Sea), and examined the influence of it on intraspecific differentiation. For this study, we analyzed morphometric measurements, acoustic variables, mitochondrial control region fragment and five microsatellite loci from nine whiskered auklet colonies spanning the breeding range. Previous research has shown a clinal variation in this species. We build on this analysis by adding auklets from more colonies, for the first time analyzing vocalizations from different colonies and genetic structure of this species. Our data supports a clinal variation in morphometric and acoustic characters with the largest size and the lowest call frequency in western birds, and the smallest size and highest call frequency in the east. We also found two mitochondrial lineages – whiskered auklets from colonies in the Sea of Okhotsk and the Commander Is. (Bering Sea) and from the Aleutian Is. (Bering Sea), that were presumably formed during Sangamonian interglacial period (115000-130000 years ago). Genetic clusters found did not reflect differences in colony attendance rhythms, suggesting that the last was shaped by other factors (e.g. differences in predator pressure) and is unlikely to have participated in the formation of population structure. Colony fidelity, mobility of birds, proximity of foraging grounds and location of colonies in relation to seasonal ice pack, seem to be more likely determinants of intraspecific differentiation.This article is protected by copyright. All rights reserved.
      PubDate: 2017-02-08T05:10:26.506022-05:
      DOI: 10.1111/jav.01124
  • Climate determinants of breeding and wintering ranges of lesser kestrels
           in Italy and predicted impacts of climate change
    • Authors: Michelangelo Morganti; Damiano Preatoni, Maurizio Sarà
      Abstract: Climate warming would theoretically create conditions for the breeding range expansion of pseudo-steppe Mediterranean and long-distance migrant species and provide the possibility for these to overwinter in the same breeding areas. However, contemporary changes in rainfall regimes might have negative effects on the climate suitability and in turn, shrink species potential range. The lesser kestrel, Falco naumanni, is highly sensitive to rainfall oscillations and has recently extended its Italian breeding range towards northern latitudes and increasing its wintering records. We modelled the effects of temperature and rainfall on current and future climate suitability for lesser kestrels in both the breeding and wintering periods by using MaxEnt. Models were based on the distribution of 298 colonies and 45 wintering records. Future climate suitability was assessed under eight different scenarios.Spring rainfall amount resulted as the main determinant of breeding climate suitability, so its predicted reduction will determine a shrinkage in suitable areas (-42.10% in 2050; -32.07% in 2070). Specifically, the 66.05% of Italian colonies will be outside the climatically suitable area by 2050. However wide areas, suitable under current climate conditions, are still not occupied by lesser kestrel and allow the potential expansion of its Italian breeding range in the short term. Temperature seasonality mainly determined the species’ winter climate suitability, which is overall predicted to boost in the next decades (+145.03% in 2050; and +123.91% in 2070). All but one future scenarios predicted a northward shift of about 40 km for both breeding and wintering climate suitability. Despite its recent expansion, we have found that climate change will pose conservation concerns for the Italian breeding population of lesser kestrels. Indeed, changes in non-climate factors will also outline the future suitability of the Italian range for lesser kestrels in both seasons with effects that might both strengthen or mitigate climate effects.This article is protected by copyright. All rights reserved.
      PubDate: 2017-02-08T05:05:37.380048-05:
      DOI: 10.1111/jav.01179
  • Age-related parasite load and longevity patterns in the sedge warbler
           Acrocephalus schoenobaenus
    • Authors: W Bielański; A. Biedrzycka, T. Zając, A. Ćmiel, W. Solarz
      Abstract: We report the results from a 9-year study on parasite infection in males of a small migrant passerine, the sedge warbler Acrocephalus schoenobaenus. Every year, for each male caught during territory establishment we estimated infection intensity of two lineages of Haemoproteus belopolskyi (SW1 and SW3), using molecular methods. We found a significant relationship between infection intensity and males’ longevity in both studied lineages. There was severe mortality of second-year sedge warblers after their first breeding season, with lower parasite load in survivors. The lower infection intensity in older age classes was related to between-individual change in both lineages, but was also a result of differences in infection intensity during the lifetime of individual males in the SW3. The relation between parasite load and longevity suggests that parasite load may be an age-dependent factor influencing individual survival.This article is protected by copyright. All rights reserved.
      PubDate: 2017-02-08T05:00:32.970545-05:
      DOI: 10.1111/jav.00949
  • Integrating demography, dispersal and interspecific interactions into bird
           distribution models
    • Authors: Damaris Zurell
      Abstract: Species’ ranges are primarily limited by the physiological (abiotic) tolerance of the species, described by their fundamental niche. Additionally, demographic processes, dispersal, and interspecific interactions with other species are shaping species distributions, resulting in the realised niche. Understanding the complex interplay between these drivers is vital for making robust biodiversity predictions to novel environments. Correlative species distribution models have been widely used to predict biodiversity response but also remain criticised, as they are not able to properly disentangle the abiotic and biotic drivers shaping species’ niches. Recent developments have thus focussed on (i) integrating demography and dispersal into species distribution models, and on (ii) integrating interspecific interactions. Here, I review recent demographic and multi-species modelling approaches and discuss critical aspects of these models that remain underexplored in general and in respect to birds, for example, the complex life histories of birds and other animals as well as the scale dependence of interspecific interactions. I conclude by formulating modelling guidelines for integrating the abiotic and biotic processes that limit species’ ranges, which will help to disentangle the complex roles of demography, dispersal and interspecific interactions in shaping species niches. Throughout, I pinpoint complexities of avian life cycles that are critical for consideration in the models and identify data requirements for operationalizing the different modelling steps.This article is protected by copyright. All rights reserved.
      PubDate: 2017-02-02T09:10:49.271627-05:
      DOI: 10.1111/jav.01225
  • Effects of flyway-wide weather conditions and breeding habitat on the
           breeding abundance of migratory boreal waterbirds
    • Authors: Diego Pavón-Jordán; Andrea Santangeli, Aleksi Lehikoinen
      Abstract: Anthropogenic habitat loss and climate change are among the major threats to biodiversity. Bioclimatic zones such as the boreal and arctic regions are undergoing rapid environmental change, which will likely trigger changes in wildlife communities. Disentangling the effects of different drivers of environmental change on species is fundamental to better understand population dynamics under changing conditions. Therefore, in this study we investigate the synergistic effect of winter and summer weather conditions and habitat type on the abundance of 17 migratory boreal waterbird species breeding in Finland using three decades (1986–2015) of count data. We found that above-average temperatures and precipitations across the western and northern range of the wintering grounds have a positive impact on breeding numbers in the following season, particularly for waterbirds breeding in eutrophic wetlands. Conversely, summer temperatures did not seem to affect waterbird abundance. Moreover, waterbird abundance was higher in eutrophic than in oligotrophic wetlands, but long term trends indicated that populations are decreasing faster in eutrophic than in oligotrophic wetlands. Our results suggest that global warming may apparently benefit waterbirds, e.g. by increased winter survival due to more favourable winter weather conditions. However, the observed population declines, particularly in eutrophic wetlands, may also indicate that the quality of breeding habitat is rapidly deteriorating through increased eutrophication in Finland which override the climatic effects. The findings of this study highlight the importance of embracing a holistic approach, from the level of a single catchment up to the whole flyway, in order to effectively address the threats that waterbirds face on their breeding as well as wintering grounds.This article is protected by copyright. All rights reserved.
      PubDate: 2017-02-02T09:05:36.588187-05:
      DOI: 10.1111/jav.01125
  • Balance between site fidelity and habitat preferences in colony site
           selection by herons and egrets
    • Authors: Luis Carrasco; Yukihiko Toquenaga, Miyuki Mashiko
      Abstract: Habitat selection in avian species is a hierarchical process driven by different factors acting at multiple scales. Habitat preferences and site fidelity are two main factors affecting how colonial birds choose their breeding locations. Although these two factors affect how colonial species choose their habitats, previous studies have only focused on one factor at a time to explain the distribution of species at regional scales. Here we used 28 years of colony location data of herons and egrets around Ibaraki prefecture in Japan in order to analyze the relative importance of habitat preferences and colony site fidelity for selecting breeding locations. We used Landsat satellite images together with a ground survey-based map to create land-use maps for past years and determine the habitats surrounding the herons and egrets colonies. Combining the estimated colony site fidelity with the habitat data, we used a random forest algorithm to create habitat selection models, which allowed us to analyze the changes in the importance of those factors over the years. We found high levels of colony site fidelity for each year of study, with its relative importance as a predictor for explaining colony distribution increasing drastically in the most recent five years. The increase in collective site fidelity could have been caused by recent changes in the population size of grey herons Ardea cinerea, a key species for colony establishment. We observed a balance between habitat preferences and colony site fidelity: habitat preferences were a more powerful predictor of colony distribution until 2008, when colony site fidelity levels were lower. Considering changes in the relative importance of these factors can lead to a better understanding of the habitat selection process and help to analyze bird species’ responses to environmental changes.
      PubDate: 2017-02-02T05:25:27.21033-05:0
      DOI: 10.1111/jav.01255
  • Arion slugs as nest predators of small passerine species – a review
    • Authors: Katarzyna Turzańska; Justyna Chachulska
      Abstract: Arionid slugs have been reported to attack nestlings of some ground- or shrub-nesting passerine birds, mainly in Europe. We review these reported cases and consider their effects. The slugs can cause grave or even fatal injuries to the nestlings. Surprisingly, no brood defence by the parents has been described. The information on the frequency of slug predation in bird populations is scanty, and the scale of the phenomenon is unknown. The expansion of the invasive Arion vulgaris Moquin-Tandon, 1855 (synonymously A. lusitanicus or A. lusitanicus auct. non Mabille, 1868) in Europe may result in an increase of the negative influence of slugs on the breeding success of some passerines in the near future.
      PubDate: 2017-01-23T06:30:25.853018-05:
      DOI: 10.1111/jav.01189
  • Plasticity in incubation behavior and shading by king rails Rallus elegans
           in response to temperature
    • Authors: Amanda J. Clauser; Susan B. McRae
      Abstract: King rails experience a wide range of temperatures during the course of the breeding season throughout their rapidly contracting geographic range. Incubating parent birds are adapted to keep their eggs within a temperature range appropriate for embryo development, but king rail clutches are at risk of exceeding lethal temperatures in the latter half of the nesting season. We investigated whether behavioral plasticity during incubation enables parents to maintain clutch temperature within tolerable limits for embryo development. Video revealed that king rail parents interrupted incubation to stand above and shade their eggs. We tested the hypothesis that the onset of shading was a direct response to ambient temperature (adaptive plasticity). We monitored clutch temperature directly by experimentally adding into clutches a model egg embedded with a programmable iButton. We measured ambient temperature at the nest site simultaneously. Parents spent proportionately more time shading and less time incubating their eggs at higher ambient temperatures. Shading may primarily function in cooling the parent. The frequency and duration of shading bouts were significantly greater at higher ambient temperatures. Parents also took more frequent but shorter recesses in hotter conditions. Diurnal recesses exposed eggs to direct sunlight, and the highest clutch temperatures were recorded under these conditions. Complete hatching failure in at least one nest was attributable to high clutch temperature for an extended period. Because mean ambient temperature increases throughout the breeding season, we investigated seasonal patterns in onset of incubation and its effect on hatching rate. Later in the season, parents tended to initiate incubation earlier, and hatching asynchrony increased significantly. Together these results suggest that breeding king rails may be constrained in their ability to cope with sustained high temperatures should seasonal averages continue to rise as predicted.
      PubDate: 2017-01-23T06:25:48.026328-05:
      DOI: 10.1111/jav.01056
  • Determining fine-scale migratory connectivity and habitat selection for a
           migratory songbird by using new GPS technology
    • Authors: K. C. Fraser; A. Shave, A. Savage, A. Ritchie, K. Bell, J. Siegrist, J. D. Ray, K. Applegate, M. Pearman
      Abstract: Migratory aerial insectivores are among the fastest declining avian groups, but our understanding of these trends has been limited by poor knowledge of migratory connectivity and the identification of critical habitat across the vast distances they travel annually. Using new, archival GPS loggers, we tracked individual purple martins Progne subis from breeding colonies across North America to determine precise ( 10 m) locations of migratory and overwintering roost locations in South America and to test hypotheses for fine-scale migratory connectivity and habitat use. We discovered weak migratory connectivity at the roost scale, and extensive, fine-scale mixing of birds in the Amazon from distant (> 2000 km) breeding sites, with some individuals sharing the same roosting trees. Despite vast tracts of contiguous forest in this region, birds occupied a much more limited habitat, with most (56%) roosts occurring on small habitat islands that were strongly associated with water. Only 17% of these roosts were in current protected areas. These data reflect a critical advance in our ability to remotely determine precise migratory connectivity and habitat selection across vast spatial scales, enhancing our understanding of population dynamics and enabling more effective conservation of species at risk.
      PubDate: 2017-01-23T06:15:31.982428-05:
      DOI: 10.1111/jav.01091
  • Tick infestation of chicks in a seabird colony varies with local breeding
           synchrony, local nest density and habitat structure
    • Authors: Alejandra G. Ramos; Hugh Drummond
      Abstract: Parasites are a major risk for group-living animals and seabirds are notoriously susceptible to ectoparasite infestations because they commonly nest in dense colonies. Ticks parasitize seabirds across all biogeographical regions and they can be particularly harmful to nestlings, but the ecological factors that affect their transmission to chicks are little studied and poorly understood. Here we show that abundance of tick larvae in blue-footed booby Sula nebouxii broods varies with local nest synchrony and density, and also with habitat structure: abundance increased with local breeding synchrony, was linearly and quadratically related to local nest density, and was highest toward the southern end of the study area which has suitable (boulder-rich) habitat for ticks. Also, with increasing chick age infestation first increased and then declined. The results of this study highlight how local physical and social environmental factors influence infestation of seabird nestlings by ticks.
      PubDate: 2017-01-23T06:15:26.296991-05:
      DOI: 10.1111/jav.01107
  • Point of no return – absence of returning birds in the otherwise
           philopatric willow warbler Phylloscopus trochilus
    • Authors: Johanna S. U. Hedlund; Frida Sjösten, Kristaps Sokolovskis, Sven Jakobsson
      Abstract: The return of individual birds to a specific area in successional years, i.e. philopatry, is a remarkable behavioural trait. Here we report on the remarkably reversed: the complete absence of returning individuals of a migratory passerine with otherwise pronounced philopatry. At a high latitude study site in Abisko (68°32ʹN, 18°80ʹE) in northern Sweden none of the banded adult willow warblers Phylloscopus trochilus returned to breed 2011–2014. This is in stark contrast to all other reports in the literature and also to our two southern study sites (at 56°56ʹN, 18°10ʹE and at 58°94ʹN, 17°14ʹE) where 18–38% of adults returned. We investigated this aberrant pattern found in Abisko by analysing three parameters known to influence philopatry; nest predation, breeding success and breeding density, and predicted that absence of philopatry should co-occur with low breeding success, low breeding density and/or high nest predation. The results did not corroborate this, except that breeding density was lower at Abisko (49–71 pairs km–2) than at the southern sites (106 pairs km–2, 101 pairs km–2). Instead, we suggest the hypothesis that the absence of philopatry is caused by an influx of southern, dispersal-prone individuals deploying another breeding strategy and that this intra-specific range expansion is enabled by milder climate and low population density.
      PubDate: 2017-01-23T06:10:33.804066-05:
      DOI: 10.1111/jav.00973
  • Cyprus wheatears Oenanthe cypriaca likely reach sub-Saharan African
           wintering grounds in a single migratory flight
    • Authors: Marina Xenophontos; Emma Blackburn, Will Cresswell
      Abstract: Long-distance migratory flights with multiple stop-overs, multiple wintering sites, and small-scale connectivity in Afro-Palearctic migrants are likely to increase their vulnerability to environmental change and lead to declining populations. Here we present the migration tracks and wintering locations of the first six Cyprus wheatears to be tracked with geolocators: a species with high survival and a stable population. We therefore predicted a non-stop flight from Cyprus to sub-Saharan wintering grounds, a single wintering area for each individual and a wide spread of wintering locations representing low migratory connectivity at the population level. The sub-Saharan wintering grounds in south Sudan, Sudan and Ethiopia were likely reached by a single flight of an average straight-line distance of 2538 km in ca 60 h, with an average minimum speed of 43.1 km h–1. The high speed of migration probably ruled out stop-overs greater than a few hours. Cyprus wheatears migrated from Cyprus in mid-late October and most probably remained at a single location throughout winter; three out of five birds with available data may have used a second site < 100 km away during February; all returned between 7–22 March when accurate geolocation data are not possible due to the equinox. Wintering locations were spread over at least 950 km. There were no tag effects on survival. Cyprus wheatears showed a migratory strategy in accordance with their observed high survival rate and demonstrated a routine flight range that allows much of the Mediterranean and the Sahara to be crossed in a rapid two and a half-day flight.
      PubDate: 2017-01-20T06:45:56.380531-05:
      DOI: 10.1111/jav.01119
  • Infection reduces anti-predator behaviors in house finches
    • Authors: James S. Adelman; Corinne Mayer, Dana M. Hawley
      Abstract: Infectious diseases can cause host mortality through direct or indirect mechanisms, including altered behavior. Diminished anti-predator behavior is among the most-studied causes of indirect mortality during infection, particularly for systems in which a parasite's life-cycle requires transmission from prey to predator. Significantly less work has examined whether directly-transmitted parasites and pathogens also reduce anti-predator behaviors. Here we test whether the directly-transmitted bacterial pathogen, Mycoplasma gallisepticum (MG), reduces responses to predation-related stimuli in house finches Haemorhous mexicanus. MG causes conjunctivitis and reduces survival among free-living finches, but rarely causes mortality in captivity, suggesting a role for indirect mechanisms. Wild-caught finches were individually housed in captivity and exposed to the following treatments: 1) visual presence of a stuffed, mounted predator (a Cooper's hawk Accipiter cooperii) or control object (a vase or a stuffed, mounted mallard duck Anas platyrhynchos), 2) vocalizations of the same predator and non-predator, 3) approach of a researcher to enclosures, and 4) simulated predator attack (capture by hand). MG infection reduced anti-predator responses during visual exposure to a mounted predator and simulated predator attack, even for birds without detectable visual obstruction from conjunctivitis. However, MG infection did not significantly alter responses during human approach or audio playback. These results are consistent with the hypothesis that predation plays a role in MG-induced mortality in the wild, with reduced locomotion, a common form of sickness behavior for many taxa, as a likely mechanism. Our results therefore suggest that additional research on the role of sickness behaviors in predation could prove illuminating.
      PubDate: 2017-01-20T06:45:48.999464-05:
      DOI: 10.1111/jav.01058
  • Feather melanin and microstructure variation in dark-eyed junco Junco
           hyemalis across an elevational gradient in the Selkirk Mountains
    • Authors: Devin R. de Zwaan; Jennifer L. Greenwood, Kathy Martin
      Abstract: Variation in feather melanism and microstructure can arise through sexual selection and ecological functional drivers. Melanin-based plumage traits are associated with sexual dichromatism and the intensity of sexual selection in many avian species, but also have several ecological benefits such as protection against ultra-violet (UV) radiation, camouflage, and feather strength. Additionally, feather microstructure influences thermoregulation. Plumage variation across species is well documented; however, the relative role of sexual selection and ecological drivers in intra-specific and within-population variation is less established. We investigated UV reflectance, melanism, and feather microstructure in a population of Oregon dark-eyed juncos Junco hyemalis oreganus between high (1900–2200 m a.s.l.) and low (450–800 m a.s.l.) elevations in the Selkirk Mountains to evaluate potential sexual selection and ecological drivers of variation. We found no difference in UV reflectance or lightness (melanism) of head feathers between elevations, but individuals at high elevation had lighter (less melanism) and less brown (less pheomelanin) body contour feathers than at low elevations. High elevation individuals also had longer contour feathers with more pronounced plumulaceous regions. Sexual dichromatism did not vary between elevations, leading us to reject sexual selection in favour of ecological functional drivers of plumage variation in this system. To our knowledge, this is the first study to identify within-population differences in feather melanism and microstructure between different elevations.
      PubDate: 2017-01-20T06:41:15.092866-05:
      DOI: 10.1111/jav.01050
  • Phylogeny of Penduline Tits inferred from mitochondrial and microsatellite
    • Authors: Hossein Barani-Beiranvand; Mansour Aliabadian, Martin Irestedt, Yanhua Qu, Jamshid Darvish, T. Szekely, Rene van Dijk, Per Ericson
      Abstract: Penduline Tits (Remiz spp) are renowned for their diverse mating and parenting strategies, and are a well-studied system by behavioural ecologists. However, the phylogenetic relationships and species delimitations within this genus are poorly understood. Here, we investigate phylogenetic relationships within the genus Remiz by examining the genetic variation in the mitochondrial cytochrome-b gene of 64 individuals and in ten autosomal microsatellite markers from 44 individuals. The taxon sampling includes individuals from all currently recognized species (R. pendulinus, R. macronyx, R. coronatus, and R. consobrinus) and most subspecies in the Palearctic region. We showed that R. coronatus and R. consobrinus are genetically well differentiated and constitute independent evolutionary lineages, separated from each other and from R. pendulinus/macronyx. However, we found no evidence for significant differentiation among R. pendulinus/macronyx individuals in mtDNA haplotypes and only marginal differences between R. pendulinus and R. macronyx in microsatellite markers. Hence, based on present data our recommendation is to treat R. pendulinus and R. macronyx as conspecific and R. coronatus and R. consobrinus as separate species.This article is protected by copyright. All rights reserved.
      PubDate: 2017-01-18T05:10:47.254738-05:
      DOI: 10.1111/jav.01163
  • Breeding phenological response to spring weather conditions in common
           Finnish birds: resident species respond stronger than migratory species
    • Authors: Edward Kluen; Riikka Nousiainen, Aleksi Lehikoinen
      Abstract: National bird-nest record schemes provide a valuable data source to study large-scale changes in basic breeding biology and effects of climate change on birds. Using nest-record scheme data from 26 common Finnish breeding bird species from whole Finland, we estimated the laydate of the first egg for 129 063 nesting attempts. We then investigated the relationship of mean spring temperature and spring precipitation sum to changes in the onset of laying over the period 1961–2012. In addition, we examine differences in response to these climatic variables for species grouped for different life history strategies; migration, diet and habitat. Finally, we test whether body size is related to the strength of phenological response. We show that 26 common Finnish breeding bird species have advanced their laying dates over time and to an increase in the mean spring temperature over the study period. When species are grouped according life history strategies, we find that breeding phenological change is negatively associated with changes in the mean spring temperature where residents respond strongest to changes in mean spring temperature, but also short- and long-distance migrants advance laydates with increasing spring temperatures. Breeding phenological change is also associated with spring precipitation, where resident species delay and short-distance migrants advance the onset of breeding. In addition we find that omnivorous species respond stronger than insectivorous species to changes in spring temperature. In contrast to results from an earlier study, we do not find evidence that small-sized species respond stronger to spring temperature than large-sized species. As climate warming is predicted to continue in the future, long-term citizen science schemes, such as the Finnish nest-card scheme, prove to be a valuable cost-effective way to monitor the environment and allow investigation into how species are responding to changes in their environment.
      PubDate: 2017-01-18T04:55:21.227888-05:
      DOI: 10.1111/jav.01110
  • Contrasting latitudinal patterns of life-history divergence in two genera
           of new world thrushes (Turdinae)
    • Authors: Andy J. Boyce; Thomas E. Martin
      Abstract: Several long-standing hypotheses have been proposed to explain latitudinal patterns of life-history strategies. Here, we test predictions of four such hypotheses (seasonality, food limitation, nest predation and adult survival probability) by examining life-history traits and age-specific mortality rates of several species of thrushes (Turdinae) based on field studies at temperate and tropical sites and data gathered from the literature. Thrushes in the genus Catharus showed the typical pattern of slower life-history strategies in the tropics while co-occuring Turdus thrushes differed much less across latitudes. Seasonality is a broadly accepted hypothesis for latitudinal patterns, but the lack of concordance in latitudinal patterns between co-existing genera that experience the same seasonal patterns suggests seasonality cannot fully explain latitudinal trait variation in thrushes. Nest-predation also could not explain patterns based on our field data and literature data for these two genera. Total feeding rates were similar, and per-nestling feeding rates were higher at tropical latitudes in both genera, suggesting food limitation does not explain trait differences in thrushes. Latitudinal patterns of life histories in these two genera were closely associated with adult survival probability. Thus, our data suggest that environmental influences on adult survival probability may play a particularly strong role in shaping latitudinal patterns of life-history traits.
      PubDate: 2017-01-18T04:51:38.781295-05:
      DOI: 10.1111/jav.01113
  • Breeding limits foraging time: evidence of interrupted foraging response
           from body mass variation in a tropical environment
    • Authors: Chima J. Nwaogu; Maurine W. Dietz, B. Irene Tieleman, Will Cresswell
      Abstract: Birds should store body reserves if starvation risk is anticipated; this is known as an ‘interrupted foraging response’. If foraging remains unrestricted, however, body mass should remain low to limit the predation risk that gaining and carrying body reserves entails. In temperate environments mass gain in female birds during breeding is often attributed to egg formation and mass loss after incubation to flight adaptation or the effect of reproductive workload, rather than as a result of an adaptive interrupted foraging response to the limited foraging time or unpredictable foraging conditions that breeding demands. In tropical environments, foraging conditions vary more within the breeding season than in temperate environments, and so studies in tropical environments are more suited to decouple the potentially confounded effects of increase in body reserves versus egg formation on the body mass of breeding birds. In this study, we test whether breeding results in an interrupted foraging response in a tropical savannah system using body mass data collected over a 15-year period from female common bulbuls Pycnonotus barbatus. This species breeds both in the wet and dry season, despite fewer resources being available in the dry season. Breeding stage predicted female body mass: body mass peaked abruptly during incubation, but was not closely associated with the egg-laying stage, and declined during brood rearing. Breeding females were heavier in the dry season than in the wet season. In the dry season, heavier birds were more likely to incubate eggs or brood chicks. These observations suggest that increased body reserves are required to buffer the consequence of limited foraging time or impoverished foraging conditions, which may be most pronounced during incubation and in the dry season, respectively. Such mass increases are consistent with an interrupted foraging response, which may apply to temperate zone birds experiencing foraging restrictions during breeding.
      PubDate: 2017-01-18T04:45:54.510981-05:
      DOI: 10.1111/jav.01132
  • Geographical Variation in Reproductive Investment across Avian Assemblages
           in Europe: Effects of Environmental Drivers Differ Between Altricial and
           Precocial Species
    • Authors: Lenka Kopsová-Storchová; David Storch, Lluús Brotons, David Hořák
      Abstract: Reproductive traits provide information about the ways by which available resources are allocated during breeding. We tested for environmental drivers of large scale geographical patterns in assemblage mean clutch size, number of broods and overall reproductive investment per breeding season in European birds. We combined data about geographical distribution with published information about reproductive traits, and calculated mean trait values for avian assemblages occurring in 50x50 km grid cells. In total, we employed data from 499 species and 2059 assemblages. As the time available for breeding and the amount of food limit the reproductive effort, we related the geographical variation in reproductive traits to the length of breeding season, normalized difference vegetation index (NDVI) as a surrogate of resource availability, and its seasonality. Geographical patterns in traits may differ between reproductive modes, thus we performed the analyses separately for altricial Passerines (N=203) and precocial non-passerine species (N=164) and controlled for the effect of taxonomy. Large clutches dominated in areas with high NDVI and, in precocial birds, also in areas with high annual seasonality and a long breeding season. High number of broods and high overall reproductive investment dominated in areas with a long breeding season, and high number of broods was found also in areas with low annual seasonality, but only in precocial species. High overall reproductive investment dominated in highly productive areas and also in areas with low annual seasonality in both groups. The increase in reproductive investment is caused mostly by an increase in the number of broods related to the length of season and partly by increase in clutch size related to NDVI. We found a negative correlation between clutch size and the number of broods in Passerines, which might suggest a trade-off between these traits. Processes behind trait patterns differ between altricial and precocial species.This article is protected by copyright. All rights reserved.
      PubDate: 2017-01-18T04:35:23.47018-05:0
      DOI: 10.1111/jav.01131
  • A small badge of longevity: opposing survival selection on the size of
           white and black wing markings
    • Authors: Tuul Sepp; Kalev Rattiste, Lauri Saks, Richard Meitern, Janek Urvik, Ants Kaasik, Peeter Hõrak
      Abstract: According to handicap principle, exaggerated ornamental traits are supposed to exert costs on their bearers. However, there is much less theoretical and practical consensus about whether and under which conditions ornament expression should positively correlate with survival. We measured age-related variation and survival selection on the size of white wing patches and black wing tips in a long-lived monogamous seabird, the common gull Larus canus. Males had larger white patches than females but patch size showed concave relationship with age irrespective of sex, suggesting that white patch size was prone to senescence in both sexes. Extent of wing tip abrasion correlated negatively with the size of white patch, suggesting, in agreement with the Zahavian handicap hypothesis that only individuals with largest ornaments are able of maintaining them and not paying cost of displaying them. Areas of white wing patches and black wing tips correlated negatively. Irrespective of sex, survival selection favored birds with larger white wing patches and smaller black wing tips, which suggests that white and black wing markings may have coevolved as reverse components of a single ornament. Altogether, our results provide an evidence for the case where survival selection on ornamental traits in females is not weaker than in males. Absence of sex differences with respect to most of observed patterns is consistent with a prediction that among monogamous long-lived species with biparental care, mutual mate choice leads to evolution of elaborate ornamental traits in both sexes.
      PubDate: 2017-01-18T04:30:23.032961-05:
      DOI: 10.1111/jav.01136
  • Climatic and geographic barriers drive distributional patterns of bird
           phenotypes within peninsular India
    • Authors: Vivek Ramachandran; V. V. Robin, Krishnapriya Tamma, Uma Ramakrishnan
      Abstract: Modern phylogenetic data provide unparalleled ability to test biogeographic paradigms, often suggested by differences in species distribution patterns. However, such approaches have been applied less at regional scales, particularly in Asia. In the absence of such data, we examine if concordance of distributional patterns for phenotypes (subspecies) suggest potential biogeographic barriers for birds in peninsular India. Specifically, we examine climatic and physical factors that might limit phenotype distributions in this region.Various physical, vegetation and climatic barriers were demarcated to identify potential biogeographic units within peninsular India. We then collated occurrence of endemic or disjunctly distributed species and subspecies within these units using published range maps. We also quantified turnover between potential units, allowing us to identify significant biogeographic barriers. Three time-step climate data (Last Glacial Maxima, mid-Holocene and present) enabled us to examine differences between these potential biogeographic regions through time.The Palk Straits, followed by the Goa Gap (∼ 16°N) and the Godavari River emerged as the major barriers in this region. The Palk Straits and Godavari are physical barriers while Goa Gap appears to be a climate-mediated ecological divide. Mountain barriers like the Palghat Gap are not the most significant barriers as previously thought. Climatically intermediate regions appeared unstable in the past and showed inconsistent affinities to different geographic units across families. We suggest that relative climatic stability of the wet regions of the southern western Ghats could be responsible for high subspecies endemism here. Our approach provides hypotheses that can be tested with comparative multi-species phylogeographic data in the future.
      PubDate: 2017-01-18T03:35:25.188149-05:
      DOI: 10.1111/jav.01278
  • Does sun glare increase antipredator behaviour in prey'
    • Authors: Guy Beauchamp
      Abstract: As the sun gradually lowers over the horizon, prey species with more sun in their eyes should have more difficulty in visually monitoring their surroundings for threats and thus experience a higher predation risk. In a unique setting, I could examine changes in antipredator behaviour in a prey species, the semipalmated sandpiper Calidris pusilla, facing attacks by peregrine falcons Falco peregrinus, which originated from the general direction of the lowering sun. I predicted gradual changes in antipredator behaviour as sun glare becomes more problematic later in the day. As the day progressed, sandpipers occurred in sparser groups when the sun glared but not when clouds obscured the sun, suggesting that fewer individuals engaged in risky foraging. Pecking rate and foraging success decreased later in the day when the sun glared but not otherwise implying an increase in vigilance at the expense of foraging. When more sun hit their eyes, sandpipers also moved faster suggesting increased skittishness. The sun glare effect might be relevant to any species foraging in open areas not only when the sun sets but also when it rises especially if predators can target prey species at these vulnerable times. The temporal gradient in predation risk that the sun glare effect creates might thus apply broadly and have important consequences for antipredator vigilance, foraging efficiency, and habitat use.
      PubDate: 2017-01-18T03:30:38.012337-05:
      DOI: 10.1111/jav.01154
  • No effect of partner age and lifespan on female age-specific reproductive
           performance in blue tits
    • Authors: Seyed Mehdi Amininasab; Martijn Hammers, Oscar Vedder, Jan Komdeur, Peter Korsten
      Abstract: Studies of age-specific reproductive performance are fundamental to our understanding of population dynamics and the evolution of life-history strategies. In species with bi-parental care, reproductive ageing trajectories of either parent may be influenced by their partner's age, but this has rarely been investigated. We investigated within-individual age-specific performance (laying date and number of eggs laid) in wild female blue tits Cyanistes caeruleus and evaluated how the age and longevity of their male partner indirectly influenced the females’ reproductive performance. Females showed clear age-dependence in both laying date and number of eggs laid. We found that female reproductive performance improved in early life, before showing a decline. Longer-lived females had an earlier laying date throughout their lives than shorter-lived females, but there was no difference in number of eggs laid between longer- and shorter-lived females. Within breeding pairs, the female's (age-specific) reproductive performance was not dependent on the age and longevity of the male partner. We conclude that the age and quality of the male partner may be of little importance for traits that are under direct female control.
      PubDate: 2017-01-18T03:25:49.934732-05:
      DOI: 10.1111/jav.00970
  • Maternal allocation in eggs when counting on helpers in a cooperatively
           breeding bird
    • Authors: Juliana Valencia; Concha Mateos, Carlos Cruz, Juan Carranza
      Abstract: For cooperatively breeding birds, it has been proposed that breeders should reduce their investment in eggs when they count on helpers, because this can be compensated for by helpers provisioning of nestlings. Data from some species have supported this prediction, but this is not the case in others. It has also been proposed that mothers should not reduce but rather increase investment if the presence of helpers enhances the reproductive value of offspring, a pattern that might also influence egg production as long as helpers are predictable for laying females. Here, we studied maternal expenditure in eggs and clutches in the Iberian magpie, to see whether mothers reduce their expenditure at the egg stage in the presence of helpers. Our results show that investment in clutches varied depending on the year, date in the season and age of the mother, but there were no reductions in maternal expenditure per individual egg when they counted on helpers. On the contrary, a pattern emerged in the opposite direction of more investment in eggs associated with the future presence of helpers at the nestling stage. Our data suggest that the predictability of helpers, along with the type of benefits accrued from the contribution of helpers, may be crucial to understanding the reaction of mothers at egg production.
      PubDate: 2017-01-18T03:10:33.741289-05:
      DOI: 10.1111/jav.01020
  • “Same procedure as last year'” – Repeatedly tracked swifts show
           individual consistency in migration pattern in successive years
    • Authors: A. H. J. Wellbrock; C. Bauch, J. Rozman, K. Witte
      Abstract: Individual migration pattern during non-breeding season is still a black box in many migratory birds. However, knowledge on both individual level and population level in migration and overwintering is fundamental to understand the life cycle of these birds and the constraints affecting them. We showed in a highly aerial migrant, the common swift Apus apus, that repeatedly tracked birds breeding at one site in Germany used the same individual-specific migration routes and wintering areas in subsequent years. In contrast, different individuals from the same breeding colony showed diverse movement patterns during non-breeding season suggesting that several suitable areas for overwintering coexist. We found lower variation in timing of autumn and spring migration within than between individuals. Our findings provide first indication of individual consistency but between-individual variation in migration pattern in a small non-passerine bird revealed by geolocators. This supports that swifts have diverse but individual-specific ‘step-by-step’ migration patterns revealing high flexibility through individual strategies.This article is protected by copyright. All rights reserved.
      PubDate: 2017-01-16T00:50:26.529418-05:
      DOI: 10.1111/jav.01251
  • Ultraconserved Elements Resolve the Phylogeny of Potoos (Aves:
    • Authors: Noor D. White; Charles Mitter, Michael J. Braun
      Abstract: In this study, we apply a genome-scale set of molecular markers, ultraconserved elements, to fully resolve the phylogeny of a family of secretive, nocturnal birds, the potoos (Nyctibiidae). This dataset provides an opportunity to explore some challenges of phylogenetic analyses of genome-scale datasets, which we address in several ways. We generate data matrices ranging between 2,610–4,175 loci (1,477,319–3,848,295 aligned base pairs) that represent versions of the data differing in whether or not alignments were trimmed prior to concatenation, and whether 100% or 75% of all taxa were required to be represented by data for inclusion of a given locus. These matrices are analyzed with both maximum likelihood and coalescent algorithms, to check for artifacts of concatenation. Then, we subsample our data matrix by locus into randomly-selected replicates of 125–1,000 loci, and compare the topologies and statistical support of the resulting trees to look for evidence of systematic error. In analyses of complete matrices, we find strong statistical support for all ingroup nodes of the tree with no evidence for systematic error introduced by alignment trimming, missing data, or concatenation. We find further support for that topology in our subsampling analyses and statistical topology tests. The earliest branch of the tree separates Nyctibius bracteatus from the rest of the potoos, followed successively by N. grandis and N. aethereus. Two pairs of species, N. jamaicensis plus N. griseus, and N. leucopterus plus N. aethereus comprise the distal tips of the tree. Finally, we compare our strongly supported topology to those of previous studies, and use the phylogeny to examine the evolutionary history of potoos.This article is protected by copyright. All rights reserved.
      PubDate: 2017-01-16T00:50:25.285181-05:
      DOI: 10.1111/jav.01313
  • House sparrows offset the physiological trade-off between immune response
           and feather growth by adjusting foraging behavior
    • Authors: Miriam Ben-Hamo; Cynthia J. Downs, Darren J. Burns, Berry Pinshow
      Abstract: Growing feathers and mounting immune responses are both energetically costly for birds. According to the life history trade-off hypothesis, it has been posited that the costs of feather growth lead to temporal isolation between molt and other expensive activities, reproduction for example. In contrast to life cycle events, the need to mount an immune response can occur at any time, including during feather growth. Thus, we hypothesized that mounting an immune response during feather growth may divert energy and resources from feather growth and impair feather renewal. To test this hypothesis, we clipped or plucked the same feathers of male house sparrows, Passer domesticus biblicus. In the clipped group (n = 16), the feathers were absent with no regrowth; in the plucked group (n = 14), feathers were absent and regrowth was initiated. We also had an intact control group of 15 sparrows. We then initiated an inflammatory immune response by subcutaneous injection over the left breast muscle of the birds with a lipopolysaccharide (LPS) and quantified behavioral and physiological responses. We predicted that sparrows with plucked feathers would incur the highest energetic costs while mounting an immune response, and would increase their foraging effort to offset this cost. We found no difference in body mass and resting metabolic rates among sparrows subjected to the different feather and immune treatments. However, we did find that while sparrows with plucked feathers increased foraging efficiency following the immune challenge by paying fewer but longer visits to the food tray, allowing them to maintain food consumption. Foraging efficiency in sparrows with clipped feathers was reduced. We also found that quality of newly grown feathers after the immune challenge was poorer in the plucked group, suggesting that mounting an immune response competes with feather growth for resources.This article is protected by copyright. All rights reserved.
      PubDate: 2017-01-16T00:50:22.415963-05:
      DOI: 10.1111/jav.01252
  • The biological background of a recurrently emerging infectious disease:
           prevalence, diversity and host specificity of Avipoxvirus in wild
           Neotropical birds
    • Authors: Michaël A. J. Moens; Javier Pérez-Tris, Borja Milá, Laura Benítez
      Abstract: Understanding which factors promote disease emergence and transmission remains a major challenge of epidemiology. A problem with research on emerging diseases is that we seldom know to what extent pathogens circulate in natural populations before emergence is already occurring. Moreover, it is critical to determine which pathogen characteristics are key to predict their emergence and invasion potential. We examined the prevalence, host specificity and evolutionary relationships of Avipoxvirus causing skin lesions in birds in two megadiverse and unexplored geographical regions of South America: an elevational gradient in the South Ecuadorian Andes, and a lowland Amazon rainforest in French Guiana. Next, we analyzed the host specificity and distribution of the worldwide Avipoxvirus diversity in order to understand their invasion potential. In French Guiana Avipoxvirus prevalence was 0 % (n=889, 94 bird species). In Ecuador, prevalence was 0.3 % (n=941, 132 bird species), with cases spanning the range of elevations between 1500 and 2500 m. These were caused by two newly described strains, one of which belonged to an American clade of Avipoxvirus shared by different bird families, and another one closely related to a strain recovered from a different family of birds in Madeira. An analysis of the host specificity and geographic distribution of all Avipoxvirus strains known worldwide finds that these viruses are usually host generalists (particularly those in the fowlpox clade), and that many closely related strains are found on multiple continents. Our study at the community level suggests that distantly related Avipoxvirus strains circulate at very low prevalence in continental tropical South America. Avipoxvirus assemblages are composed of generalist strains with different ancestry and widespread distribution, a combination of characteristics which may make these typically scarce viruses perfect candidates to emerge under favorable ecological conditions.This article is protected by copyright. All rights reserved.
      PubDate: 2017-01-16T00:15:30.151702-05:
      DOI: 10.1111/jav.01240
  • Influence of device accuracy and choice of algorithm for species
           distribution modelling of seabirds: A case study using black-browed
    • Authors: Petra Quillfeldt; Jan O. Engler, Janet R.D. Silk, Richard A. Phillips
      Abstract: Species distribution models (SDM) based on tracking data from different devices are used increasingly to explain and predict seabird distributions. However, different tracking methods provide different data resolutions, ranging from < 10m to>100km. To better understand the implications of this variation, we modeled the potential distribution of black-browed albatrosses Thalassarche melanophris from South Georgia that were simultaneously equipped with a Platform Terminal Transmitter (PTT) (high resolution) and a Global Location Sensor (GLS) logger (coarse resolution), and measured the overlap of the respective potential distribution for a total of nine different SDM algorithms. We found slightly better model fits for the PTT than for GLS data (AUC values 0.958±0.048 vs. 0.95±0.05) across all algorithms. The overlaps of the predicted distributions were higher between device types for the same algorithm, than among algorithms for either device type. Uncertainty arising from coarse-resolution location data is therefore lower than that associated with the modeling technique. Consequently, the choice of an appropriate algorithm appears to be more important than device type when applying SDMs to seabird tracking data. Despite their low accuracy, GLS data appear to be effective for analyzing the habitat preferences and distribution patterns of pelagic species.This article is protected by copyright. All rights reserved.
      PubDate: 2017-01-16T00:10:26.097813-05:
      DOI: 10.1111/jav.01238
  • Outdoor recreation causes effective habitat reduction in Capercaillie
           Tetrao urogallus: a major threat for geographically restricted populations
    • Authors: Joy Coppes; Judith Ehrlacher, Rudi Suchant, Veronika Braunisch
      Abstract: Outdoor recreation inflicts a wide array of impacts on individual animals, many of them reflected in the avoidance of disturbed areas. The scale and spatial extent, however, at which wildlife populations are affected, are mostly unclear. Particularly in geographically isolated populations, where restricted habitat availability may preclude a relocation to undisturbed areas, effective habitat reduction may remain underestimated or even unnoticed, when animals stay in disturbed areas and only show small-scale responses. Based on telemetry data, we investigated the spatial and seasonal effects of outdoor recreation - in relation to landscape and vegetation conditions – on western capercaillie Tetrao urogallus, considering two scales, homerange and within-homerange habitat selection. We determined the distance-thresholds up to which recreation infrastructures were avoided and estimated the extent of affected habitat for the isolated Black Forest (Southwestern Germany) study population. While outdoor recreation did not affect homerange selection, strong effects on habitat use within the homerange were detected: Distance to recreation infrastructure (hiking and cross-country skiing trails, ski pistes) was the main determinant of habitat selection in winter; in summer, mountain bike trails and hiker's restaurants were avoided up to an average distance of 145m (CI: 60-1092m). Around winter-infrastructure, relative avoidance was recorded up to 320m (CI: 36-327m), it was reduced, however, when dense understory provided visual cover. Of the entire population area, between 8- 20% (summer) and 8- 40% (winter) were affected by outdoor recreation, mainly in the high altitudes. Even without evident large-scale shifts in species distribution, local-scale avoidance of outdoor recreation can substantially contribute to effective habitat reduction. Based on our results we recommend a general reduction in recreation infrastructure density in key habitats, the establishment of undisturbed wildlife refuges with a diameter of at least 800m, as well as enhancing visual protection by maintaining a strip of dense understory along trails.This article is protected by copyright. All rights reserved.
      PubDate: 2017-01-16T00:10:23.785218-05:
      DOI: 10.1111/jav.01239
  • Effects of experimental night lighting on the daily timing of winter
           foraging in common European songbirds
    • Authors: Arnaud Da Silva; David Diez-Méndez, Bart Kempenaers
      Abstract: The ecological effects of light pollution are becoming better understood, especially in birds. Recent studies have shown that several bird species can use street lighting to extend activity into the night during the breeding season. However, most of these studies are correlational and little is known about the effects of artificial night lighting on the timing of activities outside the breeding season. During winter, low temperatures and short days may limit foraging opportunities and can negatively affect survival of resident birds. However, night lighting may allow them to expand the time niche available for foraging. Here, we report on a study where we repeatedly manipulated the amount of night lighting during early winter at automated feeding stations in a natural forest. We used video-recordings at the feeders to determine the time of the first (at dawn) and last (at dusk) foraging visits for six songbird species. We predicted that all species, and in particular the naturally early-foraging species, would advance their daily onset of foraging during the mornings with night lighting, but would show minimal or no delays in their daily cessation of foraging during the lighted evenings. We found that two early-foraging species, the blue tit and the great tit, started foraging earlier during the experimentally lighted mornings. However, in great tits, this effect was weak and restricted to nights with inclement weather. The light treatment did not have any effect on the start of foraging in the willow/marsh tit, the nuthatch, the European jay, and the blackbird. Artificial night lighting did not cause later foraging at dusk in any of the six species. Overall, our results suggest that artificial light during winter has only small effects on timing of foraging. We discuss these findings and the importance of temperature and winter weather in shaping the observed foraging patterns.
      PubDate: 2017-01-16T00:05:24.145147-05:
      DOI: 10.1111/jav.01232
  • Traffic noise decreases nestlings’ metabolic rates in an urban
    • Authors: François Brischoux; Alizée Meillère, Andréaz Dupoué, Olivier Lourdais, Frédéric Angelier
      Abstract: High levels of anthropogenic noise produced in urban areas are known to negatively affect wildlife. Although most research has been focused on the disturbances of communication systems, chronic noise exposure can also lead to physiological and behavioural changes that have strong consequences for fitness. For instance, behavioural changes mediated by anthropogenic noise (e.g. quality of parental care) may alter development and could influence nestling phenotype. We tested if nestling metabolism was influence by traffic noise in an urban exploiter, the House sparrow (Passer domesticus). We experimentally exposed breeding House sparrows from a rural area to a playback of traffic noise and we examined the impacts of this experimental procedure on metabolic rates and morphology of nestlings. We did not find an effect of traffic noise on the morphology of nestlings. Surprisingly, we found that disturbed nestlings had overall lower metabolic rates and mass-adjusted metabolic rates than undisturbed birds. Our results suggest a specific effect of noise exposure per se, rather than an indirect effect of anthropogenic noise through the quality of parental care. Both the proximate mechanisms and the ultimate consequences of such metabolic changes on nestlings remain unknown and deserve future experimental studies.This article is protected by copyright. All rights reserved.
      PubDate: 2017-01-16T00:00:24.065355-05:
      DOI: 10.1111/jav.01139
  • Morphological and molecular evolution and their consequences for
    • Authors: Hernán Vázquez-Miranda; Josie A. Griffin, Jay M. Sheppard, Jordan M. Herman, Octavio Rojas-Soto, Robert M. Zink
      Abstract: We evaluated geographic variation and subspecific taxonomy in the Le Conte's Thrasher (Toxostoma lecontei) by analyzing DNA sequences from 16 nuclear loci, one mitochondrial DNA locus, and four study skin characters, and compared these data sets with previously published data on plumage coloration and different mtDNA genes. Morphological support for the southernmost taxon, T. l. arenicola, is relatively weak: multivariate analyses of morphometrics or back coloration do not provide diagnostic support, although one color character differs statistically. However, combined DNA analyses indicate that T. l. arenicola is diagnosable and reciprocally monophyletic, diverging from T. l. lecontei at least 140,000 years ago. Little to no past introgression across a very short geographic distance despite the long period of isolation is strong evidence of independently evolving taxa. We suggest that the lack of morphological divergence in traits related to niche use has prevented the two taxa from invading each other's range. Despite relatively weak morphological differences we suggest that these two deeply divergent lineages merit species status, and we suggest Vizcaino Thrasher for the common name corresponding to T. l. arenicola. The population size of T. l. arenicola is small and the taxon is in need of preservation attention.This article is protected by copyright. All rights reserved.
      PubDate: 2017-01-15T22:50:29.341566-05:
      DOI: 10.1111/jav.01057
  • Movements of four native Hawaiian birds across a naturally fragmented
    • Authors: Jessie L. Knowlton; David J. Flaspohler, Eben H. Paxton, Tadashi Fukami, Christian P. Giardina, Daniel S. Gruner, Erin E. Wilson Rankin
      Abstract: Animals often increase their fitness by moving across space in response to temporal variation in habitat quality and resource availability, and as a result of intra and inter-specific interactions. The long-term persistence of populations and even whole species depends on the collective patterns of individual movements, yet animal movements have been poorly studied at the landscape level. We quantified movement behavior within four native species of Hawaiian forest birds in a complex lava-fragmented landscape: Hawai‛i ‘Amakihi (Chlorodrepanis virens), ‘Oma‘o (Myadestes obscurus), ‘Apapane (Himatione sanguinea), and ‘I‘iwi (Drepanis coccinea). We evaluated the relative importance of six potential intrinsic and extrinsic drivers of movement behavior and patch fidelity: 1) forest fragment size, 2) the presence or absence of invasive rats (Rattus sp.), 3) season, 4) species, 5) age, and 6) sex. The study was conducted across a landscape of 34 forest fragments varying in size from 0.07 to 12.37 ha, of which 16 had rats removed using a treatment-control design. We found the largest movements in the nectivorous ‘Apapane and ‘I‘iwi, intermediate levels in the generalist Hawai‛i ‘Amakihi, and shortest average movement for the ‘Oma‘o, a frugivore. We found evidence for larger patch sizes increasing patch fidelity only in the ‘Oma‘o, and an effect of rat-removal increasing patch fidelity of Hawai‛i ‘Amakihi only after two years of rat-removal. Greater movement during the non-breeding season was observed in all species, and season was an important factor in explaining higher patch fidelity in the breeding season for ‘Apapane and ‘I‘iwi. Sex was important in explaining patch fidelity in ‘Oma‘o only, with males showing higher patch fidelity. Our results provide new insights into how these native Hawaiian species will respond to a changing environment, including habitat fragmentation and changing distribution of threats from climate change.This article is protected by copyright. All rights reserved.
      PubDate: 2017-01-13T04:00:51.533761-05:
      DOI: 10.1111/jav.00924
  • Sunrise in the city: disentangling drivers of the avian dawn chorus onset
           in urban greenspaces
    • Authors: Jeffrey G-H. Lee; Ian MacGregor-Fors, Pamela J. Yeh
      Abstract: Urban systems are known to have a number of effects on avian diversity, density, and morphological and behavioral traits. However, no study to date has simultaneously examined the wide range of urban variables in relation to the avian dawn chorus, a complex behavioral phenomenon. Previous studies investigating adjustments of the dawn chorus onset in urban settings have mainly been confined to relationships with noise and light levels. In addition to noise and light levels, in this study we included other potentially related environmental characteristics describing vegetation structure, urban infrastructure, and human activity, all of which have been shown to be drivers of bird diversity in urban areas. We conducted dawn chorus surveys at 38 Los Angeles urban greenspaces and used a classification and regression tree analysis to identify specific urban scenarios that best explained timing differences in the dawn chorus onset. Our results show that light level was the most important determinant of the dawn chorus onset time, in which, counter-intuitively, bird communities in greenspaces with higher light levels had later onsets. In addition, noise was an important factor for the chorus onset in greenspaces with higher light levels. Although our results differ from those of previous studies, these findings highlight the importance of noise and light levels in explaining dawn chorus onset variation, indicating the need for further research in untangling this complex and ecologically important phenomenon.This article is protected by copyright. All rights reserved.
      PubDate: 2017-01-13T04:00:48.596572-05:
      DOI: 10.1111/jav.01042
  • How much do we know about the breeding biology of bird species in the
    • Authors: Hongtao Xiao; Yigang Hu, Zedong Lang, Bohao Fang, Weibin Guo, Qi Zhang, Xuan Pan, Xin Lu
      Abstract: Knowledge on species’ breeding biology is the building blocks of avian life history theory. A review for the current status of the knowledge at a global scale is needed to highlight the priority for future research. We collected all available information on three critical nesting parameters (clutch size, incubation period and nestling period) for the close to 10 000 bird species in the world and identified taxonomic, geographic and habitat gaps in the distribution of knowledge on avian breeding biology. The results show that only one third of all extant species are well known regarding the three nesting parameters analyzed, while the rest are partly or poorly known. Most data deficient taxonomic groups are tropical forest nesters, particularly from the Amazon basin, southeast Asia, Equatorial Africa and Madagascar – the places that harbor the world's highest bird diversity. These knowledge gaps could be hampering our understanding of avian life histories. Ornithologists are encouraged to pay more efforts to explore the breeding biology of those poorly-known species.
      PubDate: 2016-12-14T06:06:06.29401-05:0
      DOI: 10.1111/jav.00934
  • SpotEgg: an image-processing tool for automatised analysis of colouration
           and spottiness
    • Authors: Jesús Gómez; Gustavo Liñán-Cembrano
      Abstract: Colouration and patterning are widespread amongst organisms. Regarding avian eggs, colouration (reflectances) has been previously measured using spectrometers whereas spottiness has been determined using human-based scoring methods or by applying global thresholding over the luminance channel on photographs. However, the availability of powerful computers and digital image-processing algorithms and software offers new possibilities to develop systematised, automatable, and accurate methods to characterise visual information in eggs. Here, we provide a computing infrastructure (library of functions and a graphical user interface) for eggshell colouration and spottiness analysis called SpotEgg, which runs over MATLAB. Compared to previous methods, our method offers four novelties for eggshell visual analysis. First, we have developed a standardised non-human biased method to determine spottiness. Spottiness determination is based on four parameters that allow direct comparisons between studies and may improve results when relating colouration and patterning to pigment extraction. Second, researcher time devoted to routine tasks is remarkably reduced thanks to the incorporation of image-processing techniques that automatically detect the colour reference chart and egg-like shapes in the scene. Third, SpotEgg reduces the errors in colour estimation through the eggshell that are created by the different angles of view subtended from different parts of the eggshell and the optical centre of the camera. Fourth, SpotEgg runs automatic Fractal Dimension analysis (a measure of how the details in a pattern change with the scale at which this pattern is measured) of the spots pattern in case researchers want to relate other measurements with this special spatial pattern. Finally, although initially conceived for eggshell analysis, SpotEgg can also be applied in images containing objects different from eggs as feathers, frogs, insects, etc., since it allows the user to manually draw any region to be analysed making this tool useful not only for oologist but also for other evolutionary biologists.
      PubDate: 2016-12-13T07:45:26.311998-05:
      DOI: 10.1111/jav.01117
  • Reduced sexual dichromatism, mutual ornamentation, and individual quality
           in the monogamous Zenaida dove Zenaida aurita
    • Authors: Aurélie Quinard; Frank Cézilly, Sébastien Motreuil, Jean-Marc Rossi, Clotilde Biard
      Abstract: Although variation in plumage coloration is known to occur both between and within sexes, its study remains limited to a few bird families. The Zenaida dove Zenaida aurita is a socially monogamous tropical columbid bird species, characterized by an overall cinnamon-brownish plumage and structural colorations on the head and neck. The species has been described as sexually dichromatic for plumage, although color differences between males and females are not obvious in the field. We investigated variation in the presumably melanin-based color of the crown, mantle, breast, and belly, in the iridescent dark-blue streaks on the head, and in the symmetric iridescent patches on the neck, over the whole spectrum visible to birds. Further, unlike most previous studies, we assessed covariation between plumage color and phenotypic traits in both males and females in relation to the putative signaling function of ornaments. Zenaida doves appeared to be slightly sexually dichromatic for the hue of pigment-based colored areas, with males being on average more reddish than females. However, this difference was not discernible when considering the avian visual system. Conversely, although the reflectance spectra of iridescent plumage did not significantly differ between sexes in brightness, chroma or spectral position of the peaks, color discrimination analyses showed that individuals should be able to perceive between- or within-sex differences in the color of the iridescent patch. In addition, several color parameters of brown and iridescent feathers were significantly related to territorial status, body condition, wing chord, and, albeit weakly, to individual multilocus heterozygosity. Overall, our results thus suggest that plumage color might be a reliable signal of quality in individuals of both sexes in this species. Further studies are needed to test the potential implication of plumage coloration in mate choice and mating patterns in the Zenaida dove.
      PubDate: 2016-12-13T07:35:24.584013-05:
      DOI: 10.1111/jav.00902
  • Reexamining Phylloscopus trochiloides complex as a ring species: A
           refugial counter-hypothesis
    • Authors: A. Townsend Peterson; Tashitso Anamza
      Abstract: The idea of ring species has been viewed as a demonstration of the potential for species-level differentiation produced by isolation by distance in otherwise continuous populations. Although the concept is attractive, the list of empirical examples has narrowed significantly as detailed studies have been carried out. One of the few examples still cited among birds is the warbler species complex Phylloscopus trochiloides, which comprises P. trochiloides sensu stricto, P. plumbeitarsus, and P. nitidus. The ring comprises a series of populations surrounding the Tibetan Plateau in which a species-level break is apparent at the north end of the ring. Although recent theoretical treatments have indicated that such differentiation is possible in theory, recent genomic analyses indicated multiple differentiated populations around the ring unlikely to have resulted from isolation by distance. Here, we complement the genomic studies to date with paleodistributional projections of ecological niche models that provide further evidence for multiple, isolated refugia around the ring during and since the Late Pleistocene. As such, this group should not be interpreted as exemplifying an isolation-by-distance mechanism of speciation, and should no longer be considered as a ring species: genomic and geographic evidence coincide in indicating that its differentiation took place in allopatry.This article is protected by copyright. All rights reserved.
      PubDate: 2016-11-29T00:50:27.889651-05:
      DOI: 10.1111/jav.01167
  • A complete molecular phylogeny of Claravis confirms its paraphyly within
           small New World ground-doves (Aves: Peristerinae) and implies multiple
           plumage state transitions
    • Authors: Andrew D. Sweet; J. Dylan Maddox, Kevin P. Johnson
      Abstract: The three species in the genus Claravis (Aves: Peristerinae) are unique among members of the small New World ground-dove clade. All three species inhabit forested areas rather than open scrubby habitat, and exhibit obvious sexual dichromatism. However, the phylogenetic relationships within Claravis remain unknown. The only molecular phylogenetic study to include more than one species of Claravis indicated the genus is paraphyletic. Here we include molecular data from all three Claravis species, including sequences from a museum skin of the previously unsampled Claravis geoffroyi (purple-winged ground-dove). Using both mitochondrial and nuclear loci, we estimate phylogenies and divergence times for the small New World ground-dove clade. We also use ancestral state reconstruction methods to infer the evolution of male blue plumage (and thus sexual dimorphism) in the clade. As in the previous study we recover Claravis as a paraphyletic group, but with Claravis geoffroyi as the sister species to Claravis mondetoura (maroon-chested ground-dove). This result has important implications for the evolutionary history of the small New World ground-dove clade. In particular, we recover multiple independent transitions between the monomorphic and dimorphic plumage states, which perhaps indicates sexual dimorphism arose twice in the group.
      PubDate: 2016-11-18T05:05:21.658976-05:
      DOI: 10.1111/jav.01077
  • How does an increase in minimum daily temperatures during incubation
           influence reproduction in the great tit (Parus major)'
    • Authors: Marie Vaugoyeau; Sandrine Meylan, Clotilde Biard
      Abstract: Temperature variation affects all life stages of organisms, especially early development, and considering global warming, it is urgent to understand precisely its consequences. In egg-laying species, incubation behaviour can buffer embryo developmental temperature variation and influence offspring development. We experimentally investigated the effect of an increase in minimum daily nest temperature during incubation in the great tit (Parus major), by placing a hand warming pad under the nest in the evenings. As compared to controls, the experimental treatment increased nest temperature at night by an average of 4°C, and this increase carried over to the following day. We measured the consequences of this mainly nocturnal temperature increase during incubation on (i) parental behaviour (incubation and nestling feeding), (ii) parental health (quantified by body condition, immune status, physiological and oxidative stress) and (iii) reproductive success (nestling body condition, growth, i.e. mass gain, hatching and fledging success, and nestling immune status, physiological and oxidative stress). This study yielded three major results. First, we found that heating the nest did not change the duration of incubation as compared to controls. Second, increasing nest temperature during incubation decreased nestling feeding behaviour but did not affect parental health in terms of body condition, immune status, physiological and oxidative stress. Third, nestling mass at hatching was greater but nestling mass gain was slower in heated nests than in control nests, resulting in similar fledging mass. The present study demonstrates that increased environmental temperatures during incubation influenced nestling development in the great tit and especially hatchling mass, which might produce long-term life history consequences.This article is protected by copyright. All rights reserved.
      PubDate: 2016-11-17T09:20:28.342579-05:
      DOI: 10.1111/jav.01208
  • Arrival and onset of breeding of three passerine birds in Eastern Finland
           tracks climatic variation and phenology of insects
    • Authors: Anu Valtonen; Raimo Latja, Reima Leinonen, Hannu Pöysä
      Abstract: Anthropogenic climate change poses a challenge to the annual cycles of migratory birds. It has become urgent to understand whether migratory birds are able to advance their spring phenology when the climate is warming and whether they are able to adjust these phenological phases to the spring phenology in their breeding areas. In this work, we studied long-term trends in first arrival and onset of breeding for three passerine birds in Eastern Finland; the Pied Flycatcher (Ficedula hypoleuca), the Common Redstart (Phoenicurus phoenicurus) and the Great Tit (Parus major). The Pied Flycatcher and the Common Redstart are long-distance migrants while the Great Tit is a partial migrant in Finland. We asked what environmental variables best explain the first arrival or onset of breeding, if there is evidence of “thermal delay” (long-term increase in the accumulated temperatures) at arrival or onset of breeding and if the interannual variation in the onset of breeding correlates with variation in spring phenology of local insects. We found that the Pied Flycatcher and the Common Redstart had advanced their first arrival (explained by increased temperatures at the migration route), but we found no long-term change in the onset of breeding (explained by local temperatures). Also, the onset of breeding of the Great Tit is tracking local temperatures. We found no or only weak evidence of thermal delay at arrival or onset of breeding for any of the species. The onsets of breeding for the Pied Flycatcher and the Great Tit are also closely tracking the spring phenology of the local insects. The stable or increasing population sizes of all three species in Finland could be a result from their ability to effectively track climatic and environmental variation.This article is protected by copyright. All rights reserved.
      PubDate: 2016-11-10T02:50:29.234286-05:
      DOI: 10.1111/jav.01128
  • Northern flickers only work when they have to: how individual traits,
           population size and landscape disturbances affect excavation rates of an
           ecosystem engineer
    • Authors: Karen L. Wiebe
      Abstract: Woodpeckers are considered ecosystem engineers because they excavate tree cavities which are used subsequently by many species of secondary cavity nesters for breeding. Woodpeckers have the choice of excavating a new hole or reusing an existing one, and this propensity to excavate (e) may affect community dynamics but has rarely been investigated. Using 18 years of data on a population of northern flickers Colaptes auratus, I tested six hypotheses to explain the propensity to excavate (e) in a landscape which experienced two types of disturbance: pine beetles and wildfires. Woodpecker age, breeding experience and mate retention had little influence on e which varied between 13–39% annually and averaged 23% for 1843 first nests over the 18 yr. Body size and body condition of males and females were not associated with e but rates of excavation declined seasonally, suggesting time rather than energy costs limited excavation effort. Reduced cavity availability mediated through high conspecific density coupled with wildfires triggered relatively high excavation rates, up to 39% but e decreased to baseline levels three years after the landscape disturbances. Nearly 2/3 of males did not excavate in their lifetime but apparently, e is great enough to balance the average rate of cavity tree loss in this forest which is 11% annually. Excavation propensity in flickers is flexible, but the birds reduce their work levels if there is a surplus of holes available.
      PubDate: 2016-11-07T07:06:29.162571-05:
      DOI: 10.1111/jav.01180
  • Rapid mobilization of abdominal fat in migrating eared grebes
    • Authors: Lorian Cobra Straker; Joseph R. Jehl
      Abstract: Eared grebes Podiceps nigricollis, like shorebirds and other long-distance migrants, lay down large amounts of fat to power their journeys. To investigate the pattern of how fat and soft tissue might be mobilized, we used grebes killed in migration and applied computed tomography to reconstruct how stores in the chest, thorax, and abdomen were reduced as body weight decreased. Fat and soft tissue were each mobilized at a constant rate through the entire migration. Fat stores in birds embarking on migration were greater in the abdomen than thorax than chest. In contrast to previous studies indicating that abdominal fat was mobilized first, we found that fat from all areas was mobilized concurrently, but that abdominal fat was catabolized at a greater rate. We suggest why this pattern might be advantageous, consider whether inter-depot differences in fat composition might be involved, and note possible energetic consequences. Whether our findings pertain to other obese or long distance migrants remains to be determined.
      PubDate: 2016-11-07T07:03:15.137661-05:
      DOI: 10.1111/jav.01007
  • Weather-mediated decline in prey delivery rates causes food-limitation in
           a top avian predator
    • Authors: Barry G. Robinson; Alastair Franke, Andrew E. Derocher
      Abstract: Inclement weather can negatively affect breeding birds directly by exposure to factors such as severe temperature and rainfall, or indirectly by reducing food supply. During a three-year study of Arctic peregrine falcons (Falco peregrinus tundrius) breeding in Nunavut, Canada, we estimated annual prey density at a biologically relevant scale (i.e., the home range of breeding pairs), and examine the manner in which prey density and within-season weather conditions influenced occupancy of breeding sites, egg-laying, hatch rate, prey delivery rates, and growth and survivability of nestlings. We found that occupancy of breeding sites was consistently high. As a proportion of the number of eggs laid, hatch rate did not change among years, but the number of eggs laid per occupied site declined in the third year of the. In the first two years of the study, the number of nestlings per occupied sited was high, but declined in the third year. Total prey density at the home range scale was similar in 2010 and 2012, while the highest prey density was recorded in 2011. In general, total prey delivery rates were similar in 2011 and 2012, and were greatest in 2010. Nestling growth rates were similar in 2010 and 2011, but were markedly different in 2012; for both sexes the period of rapid growth was of shorter duration in 2012 and asymptotic weights were lower.This article is protected by copyright. All rights reserved.
      PubDate: 2016-11-03T08:26:20.024669-05:
      DOI: 10.1111/jav.01130
  • Kind to kin: weak interference competition among white stork Ciconia
           ciconia broodmates
    • Authors: José María Romero; Tomás Redondo
      Abstract: Altricial nestlings in structured families show a diverse array of behavioural mechanisms to compete for food, ranging from signalling scrambles to aggressive interference. Rates of filial infanticide are moderately high in white storks. It has been hypothesized that this unusual behaviour is an adaptive parental response to the absence of efficient mechanisms of brood reduction (aggression or direct physical interference) by nestlings. To test this latter assumption, we analyzed video recordings of 41 complete feeding episodes at 32 broods during the first half of the nestling period, when nestlings complete 90% of growth and chick mortality and size asymmetries are highest. Parents delivered food to all nestlings simultaneously by regurgitating on the nest floor. No direct (bill to bill) feeding was recorded. Senior nestlings were never observed to limit their junior nestlings from eating food, either by aggression or physical interference. Experimental feeding tests revealed that heavier nestlings handled prey items more efficiently and ate food at a higher speed. The high degree of tolerance shown by senior nestlings is unusual among birds with similar ecological and phylogenetic affinities, such as herons. Tolerance by seniors cannot be easily explained by absence of parental favouritism or proximate factors known to affect the occurrence of sibling aggression in other species (rate of food transfer, brood size, hatching asynchrony or length of nestling period).
      PubDate: 2016-10-25T08:30:25.123066-05:
      DOI: 10.1111/jav.00983
  • Variation in nestling body condition and wing development predict
           cause-specific mortality in fledgling dickcissels
    • Authors: Todd M. Jones; Michael P. Ward, Thomas J. Benson, Jeffrey D. Brawn
      Abstract: Phenotypic traits developed in one life-history stage can carryover and affect survival in subsequent stages. For songbirds, carryover effects from the pre- to post-fledging period may be crucial for survival but are poorly understood. We assessed whether juvenile body condition and wing development at fledging influenced survival during the post-fledging period in the dickcissel Spiza americana. We found pre- to post-fledging carryover effects on fledgling survival for both traits during the ‘early part’ – first four days – of the post-fledging period. Survival benefits of each trait depended on cause-specific sources of mortality; individuals in better body condition were less likely to die from exposure to adverse environmental conditions, whereas those with more advanced wing development were less likely to be preyed upon. Fledglings with more advanced wing development were comparatively more active and mobile earlier in the post-fledging period, suggesting they were better able to avoid predators. Our results provide some of the first evidence linking development of juvenile phenotypic traits to survival against specific sources of post-fledging mortality in songbirds. Further investigation into pre- to post-fledging carryover effects may yield important insights into avian life-history evolution.
      PubDate: 2016-10-21T10:40:35.564665-05:
      DOI: 10.1111/jav.01143
  • Pair complementarity influences reproductive output in the polymorphic
           black sparrowhawk Accipiter melanoleucus
    • Authors: Gareth Tate; Petra Sumasgutner, Ann Koeslag, Arjun Amar
      Abstract: How multiple morphs are maintained within populations of colour polymorphic bird species remains a challenging question in evolutionary ecology. In some systems, differential productivity or survival between morphs are thought to play a role. Here we examine key demographic parameters between the two discrete adult morphs that characterise the polymorphic black sparrowhawk Accipiter melanoleucus. Using long-term breeding and survival data from a population on the Cape Peninsula, South Africa, we test for differences in reproductive performance between light and dark morphs, both in isolation and in combination with their partner morph and adult survival between morphs. We found that neither morph had a specific advantage in terms of productivity or survival. Despite this lack of difference between the individual morphs, we did however find that morph combination of adult pairs influenced productivity significantly, with mixed-pairs producing more offspring per year than pairs consisting of the same morph. The body condition of the offspring showed the opposite relationship, with nestlings of mixed-pairs having lower body condition than nestlings of like-pairs. While our results suggest an advantage of mating with the opposite morph, there was no evidence for disassortative mating; instead breeding pair morph combinations were random with respect to the background frequencies of the two morphs. Higher productivity of mixed-pairs may be the result of the complementary nature of care provided by the different morphs. We propose that differential foraging success between black sparrowhawk morphs under varying light conditions allows mixed-pairs to expand their foraging niche. We conclude that emergent pair-level properties may play an important role in promoting and maintaining polymorphism and may be important for other bird species which display bi-parental care.
      PubDate: 2016-10-21T10:40:26.239204-05:
      DOI: 10.1111/jav.01100
  • Winter territory prospecting is associated with life-history stage but not
           activity in a passerine
    • Authors: Alfredo Sánchez-Tójar; Isabel Winney, Antje Girndt, Mirre J. P. Simons, Shinichi Nakagawa, Terry Burke, Julia Schroeder
      Abstract: Finding a high quality territory is essential for many animals to reproduce successfully. Despite its importance for fitness, we know little about the process of territory prospecting in wild birds, and whether individual traits and behaviours, such as personality, co-vary with territory prospecting. Here, we use long-term data from a wild, insular house sparrow Passer domesticus population to test three hypotheses about territory fidelity and prospecting: 1) house sparrows show high territory fidelity between years and also during winter. 2) Individuals will prospect for a breeding territory during their first winter whereas older, more experienced individuals will keep a territory from previous years and will, therefore, show no or reduced winter territory prospecting. 3) More active behavioural types will prospect more than less active behavioural types. We use data from four winters from automatically, daily recorded nest-box visits of 188 birds of known age. The number of nest-boxes that each individual visited within each winter was used as a proxy of winter territory prospecting. We show that house sparrows visit multiple nest-boxes during their first winter, whereas older individuals keep territories year-round and, potentially because of this, indeed show reduced winter territory prospecting. Activity was not associated with the number of nest-boxes visited. Further research is needed to investigate whether time of territory and mate acquisition differs among individuals and the possible effect on lifetime fitness.
      PubDate: 2016-10-21T10:40:23.761837-05:
      DOI: 10.1111/jav.01055
  • Early exposure to a bacterial endotoxin advances the onset of moult in the
           European starling
    • Authors: Simone Pirrello; Andrea Pilastro, Diego Rubolini, Jacopo G. Cecere, Andrea Romano, Alessandro Andreotti, Stefano Volponi, Nicola Saino, Matteo Griggio, Lorenzo Serra
      Abstract: In animals, events occurring early in life can have profound effects on subsequent life-history events. Early developmental stresses often produce negative long-lasting impacts, although positive effects of mild stressors have also been documented. Most studies of birds have investigated the effects of events occurring at early developmental stages on the timing of migration or reproduction, but little is known on the long-term effects of these early events on moulting and plumage quality. We exposed European starling Sturnus vulgaris nestlings to an immune challenge to assess the effects of a developmental stress on the timing of the first (post-juvenile) and second (post-breeding) complete annual moult, the length of the flight feathers, and the length and colouration of ornamental throat feathers. The nestlings were transferred to indoor aviaries before fledgling and kept in captivity until the end of post-breeding moult. Individuals treated with Escherichia coli lypopolysaccharide (LPS) started both moult cycles earlier compared to control siblings. Moult duration was unaffected by the immune challenge, but an advanced moult onset resulted in a longer moult duration. Moreover, female (but not male) throat feather colouration of LPS-injected individuals showed a reduced UV chroma. We argue that an early activation of the immune system caused by LPS may allow nestlings to better cope with post-fledging stresses and lead to an earlier moult onset. The effect of early LPS exposure was remarkably persistent, as it was still visible more than one year after the treatment, and highlighted the importance of early developmental stresses in shaping subsequent major life-history traits, including the timing of moult in birds.
      PubDate: 2016-08-16T06:45:24.079516-05:
      DOI: 10.1111/jav.01017
  • Decoding colouration of begging traits by the experimental addition of the
           appetite enhancer cyproheptadine hydrochloride in magpie Pica pica
    • Authors: David Martín-Gálvez; Juan J. Soler
      Abstract: The colouration of some traits in nestlings of altricial birds may influence parental food allocation as it may reflect physical condition or hunger. There is increasing evidence of the relationship between colouration of begging traits and nestling performance. However, evidence of the influence of hunger level on nestling colouration is scarce, mainly because of difficulty of distinguishing between the effects of physical condition and hunger levels. Here, we used the appetite stimulant cyproheptadine hydrochloride to increase the sensation of hunger of magpie Pica pica nestlings for eight days and assessed the effect on the colouration of rictal flanges, mouth and body skin. We found that nestlings administered with cyproheptadine had flanges more conspicuous (chromatic visual contrast), more UV coloured and less yellow coloured than their control nestmates. Conversely, mouths of experimental nestlings were more yellow coloured and less UV coloured than controls. Our pharmacological experiment affected the strength of the relationship between body mass and some colour components of body skin (chromatic and achromatic visual contrasts, UV–chroma and yellow–chroma) and of rictal flanges (chromatic visual contrasts, UV–chroma and yellow–chroma), but not for mouth colouration. These results taken together suggest that the effect of the cyproheptadine on nestling colourations is probably mediated by an increase in hunger levels of nestlings for rictal flanges and body skin colourations, and by an increase in physical condition in the case of mouth coloration.
      PubDate: 2016-08-16T06:10:23.192616-05:
      DOI: 10.1111/jav.00641
  • Trade-offs between reproduction and self-maintenance (immune function and
           body mass) in a small seabird, the little auk
    • Authors: Izabela Kulaszewicz; Katarzyna Wojczulanis-Jakubas, Dariusz Jakubas
      Abstract: Breeding season is the most energetically and physiologically demanding phase in the avian annual cycle, challenging adults' physiology and survival. However, the timing and extent that self-maintenance of breeding adults is compromised during the breeding season is poorly understood. We investigated the trade-off between reproduction and self-maintenance in relation to breeding phase (prelaying, incubation, chick rearing) and sex in a small Arctic seabird, the little auk Alle alle. To measure a bird's allocation of time for self-maintenance, we examined size-adjusted body mass and immunocompetence expressed by bacteria (Escherichia coli) killing capacity (BKC) of blood plasma, heterophils/lymphocyte ratio (H/L) and their numbers of particular leucocytes per 10 000 red blood cells (RBC). We found that size-adjusted body mass decreased as the breeding season progressed. BKC, number of heterophils and H/L values were all was significantly higher at prelaying when compared to all other phases. Interestingly, we found that heavier individuals had higher BKC and number heterophils at the prelaying and chick rearing phases than light individuals. There were no differences by sex in any studied variables. Our results indicate that immunocompetence and body mass of breeding adults decreases over the course of breeding season. The efficiency of the immune system appears to be dependent on the bird's body reserves. Our results suggest that little auks allocation of resources into reproduction negatively affects their self-maintenance.
      PubDate: 2016-08-16T06:05:22.467668-05:
      DOI: 10.1111/jav.01000
  • Non-moulted primary coverts correlate with rapid primary moulting
    • Authors: Yosef Kiat; Ido Izhaki
      Abstract: Time constraint is a main factor which affects the moult strategies in passerines, mainly during the first year of life. The variability of moult strategies between species is associated with the extent of the moult. In the first year of life, the extent of the moult is highly variable between species and individuals. In most passerine species, juveniles only renew some of their feathers, but the factors that govern which feathers are renewed and which are retained have been largely overlooked. Here we examine the common pattern of non-moulted primary coverts (PC) in passerines during the first-year moult cycle (post-juvenile and first-year pre-breeding moults). On the interspecific level we found that among 63 species of passerines, PCs are the least commonly moulted feather tract. For five species (Hirundo rustica, Pycnonotus xanthopygos, Prinia gracilis, Acrocephalus stentoreus and Passer moabiticus) which perform a complete post-juvenile moult, we found that the PC moult occurs over a longer period than greater coverts (GCs) and is sequential (non-simultaneous). At the intraspecific level, we found that the main difference between a partial and complete moult in Prinia gracilis is the moulting or non-moulting of the PCs. We also demonstrate that for Prinia gracilis 1) juveniles which do not moult their PCs, moult their primaries at a higher speed than those which moult their PCs and 2) area/mass ratio of PCs is lower than of GCs. These two findings may explain why many passerines skip PC renewal during the first year of life. Because the PC moult lasts a long time, forgoing this moult enables long term resource savings that allow for dealing with time constraints. Our results highlight the adaptive advantages of non-moulted PCs in cases of time constraints.
      PubDate: 2016-08-16T01:25:26.711526-05:
      DOI: 10.1111/jav.00939
  • Elevational replacement of two Himalayan titmice: interspecific
           competition or habitat preference'
    • Abstract: Elevational species replacement is a widely documented pattern in montane species. Although interspecific competition has been shown to be important in setting species elevational limits in tropical habitats, its effect in species of temperate regions is poorly studied. We tested the role of interspecific competition for space in the breeding season and for food in the non-breeding season in mediating the distribution of two resident titmice species in the Himalayas. We show that high elevation green-backed tits (Parus monticolus) are behaviourally dominant over low elevation cinereous tits (Parus cinereus) in both song playback and feeder trials. Despite being subordinate, at their elevational upper limit, cinereous tits occur in sympatry in human modified habitats. Our study suggests that the loss of natural habitats in the sympatric zone, not interspecific competition, might be limiting the distribution of the high-elevation green-backed tits and facilitating an upward range shift through human association in cinereous tits.
  • Diurnal body temperature patterns in free-ranging populations of two
           southern African arid-zone nightjars
    • Abstract: Endotherms allocate large amounts of energy and water to the regulation of a precise body temperature (Tb), but can potentially reduce thermoregulatory costs by allowing Tb to deviate from normothermic levels. Many data on heterothermy at low air temperatures (Ta) exist for caprimulgids, whereas data on thermoregulation at high Ta are largely absent, despite members of this taxon frequently roosting and nesting in sites exposed to high operative temperatures. We investigated thermoregulation in free-ranging Rufous-cheeked Nightjars (Caprimulgus rufigena) and Freckled Nightjars (Caprimulgus tristigma) in the southern African arid zone. Individuals of both species showed labile Tb fluctuating around a single modal Tb (Tb-mod). Average Tb-mod was 39.7 °C for Rufous-cheeked Nightjars and 39.0 °C for Freckled Nightjars. In both species, diurnal Tb increased with increasing Ta. At Ta ≥ 38 °C, Rufous-cheeked Nightjar mean Tb increased to 42 °C, equivalent to 2.3 °C above Tb-mod. Under similar conditions, Freckled Nightjar Tb was on average only 1.1 °C above Tb-mod, with a mean Tb of 40.0 °C. Freckled Nightjars are one of the most heterothermic caprimulgids investigated to date, but our data suggest that during hot conditions this species maintains Tb within a narrow range above Tb-mod, possibly reflecting an evolutionary tradeoff between decreased thermal sensitivity to lower Tb but increased sensitivity to high Tb. These findings reveal how general thermoregulatory patterns at similar Ta can vary even among closely related species.This article is protected by copyright. All rights reserved.
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