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  Subjects -> BIOLOGY (Total: 2927 journals)
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BIOLOGY (1420 journals)            First | 1 2 3 4 5 6 7 8 | Last

Showing 1201 - 1400 of 1720 Journals sorted alphabetically
Reports in Parasitology     Open Access   (Followers: 2)
Reports on Mathematical Physics     Full-text available via subscription  
Reports on Progress in Physics     Full-text available via subscription   (Followers: 2)
Reproductive Biology Insights     Open Access   (Followers: 1)
Reproductive Toxicology     Hybrid Journal   (Followers: 14)
Research & Reviews : Journal of Computational Biology     Full-text available via subscription   (Followers: 2)
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: 10)
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: 30)
Reviews of Modern Physics     Full-text available via subscription   (Followers: 18)
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 Educación en Biología     Open Access  
Revista de la Ciencia del Suelo y Nutricion Vegetal     Open Access  
Revista de Protección Vegetal     Open Access  
Revista Eletrônica de Biologia     Open Access  
Revista Eletrônica TECCEN     Open Access  
Revista Fitotecnia Mexicana     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     Full-text available via subscription   (Followers: 3)
Risk Analysis     Hybrid Journal   (Followers: 30)
RNA     Hybrid Journal   (Followers: 9)
RNA & Disease     Open Access  
RNA Biology     Full-text available via subscription   (Followers: 3)
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  
Rwanda Journal     Full-text available via subscription  
Saudi Journal of Biological Sciences     Open Access   (Followers: 1)
Scholars' Research Journal     Open Access  
Science and Engineering Ethics     Hybrid Journal   (Followers: 6)
Science China Life Sciences     Open Access  
Science Signaling     Full-text available via subscription   (Followers: 18)
Science Technology & Society     Hybrid Journal   (Followers: 2)
Scientific Journal of Biological Sciences     Open Access   (Followers: 1)
Scientific Reports     Open Access   (Followers: 19)
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: 1)
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: 5)
Seminars in Hematology     Hybrid Journal   (Followers: 10)
Sensing and Bio-Sensing Research     Open Access  
Sensors     Open Access   (Followers: 9)
Sexual Development     Full-text available via subscription   (Followers: 1)
Sierra Leone Journal of Biomedical Research     Open Access  
Signal Transduction     Hybrid Journal  
Signal Transduction Insights     Open Access   (Followers: 2)
Simbiosis : Journal of Biological Sciences     Open Access  
SINET : Ethiopian Journal of Science     Open Access   (Followers: 7)
Single Molecules     Hybrid Journal  
Small     Hybrid Journal   (Followers: 8)
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: 2)
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)
Standards in Genomic Sciences     Open Access  
Statistics in Biosciences     Hybrid Journal   (Followers: 2)
Stem Cell and Translational Investigation     Open Access   (Followers: 1)
Stem Cell Biology and Research     Open Access   (Followers: 3)
Stem Cell Discovery     Open Access   (Followers: 2)
Stem Cell Epigenetics     Open Access   (Followers: 2)
Stem Cell Reports     Open Access   (Followers: 6)
Stem Cell Research     Open Access   (Followers: 13)
Stem Cell Reviews and Reports     Hybrid Journal   (Followers: 4)
Stem Cells     Hybrid Journal   (Followers: 9)
Stem Cells and Cloning: Advances and Applications     Open Access   (Followers: 1)
Stem Cells International     Open Access  
Steroids     Hybrid Journal  
Studies in Mycology     Open Access  
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: 14)
Sustainability : The Journal of Record     Hybrid Journal   (Followers: 5)
Sustentabilidade em Debate     Open Access  
Symbiosis     Hybrid Journal   (Followers: 1)
Synthesis Lectures on Biomedical Engineering     Full-text available via subscription  
Systematic Biology     Hybrid Journal   (Followers: 13)
Systematics and Biodiversity     Hybrid Journal   (Followers: 7)
Systems and Synthetic Biology     Hybrid Journal   (Followers: 10)
Systems Biology in Reproductive Medicine     Hybrid Journal  
Taprobanica : The Journal of Asian Biodiversity     Open Access  
Taxon     Full-text available via subscription   (Followers: 4)
Telomere and Telomerase     Open Access  
Terrestrial Arthropod Reviews     Hybrid Journal  
The Anatomical Record : Advances in Integrative Anatomy and Evolutionary Biology     Hybrid Journal   (Followers: 1)
The Botulinum J.     Hybrid Journal  
The Breast Journal     Hybrid Journal   (Followers: 2)
The Bryologist     Full-text available via subscription   (Followers: 8)
The Cerebellum     Hybrid Journal   (Followers: 1)
The Coleopterists Bulletin     Full-text available via subscription   (Followers: 1)
The Condor     Full-text available via subscription   (Followers: 29)
The Enzymes     Full-text available via subscription   (Followers: 1)
The FASEB Journal     Full-text available via subscription   (Followers: 18)
The Herpetological Journal     Full-text available via subscription   (Followers: 5)
The International Journal of Advanced Manufacturing Technology     Hybrid Journal   (Followers: 4)
The Journal of Technology Transfer     Hybrid Journal   (Followers: 7)
The Knee     Hybrid Journal   (Followers: 14)
The Lichenologist     Hybrid Journal   (Followers: 5)
The Nucleus     Hybrid Journal   (Followers: 1)
The Physics of Metals and Metallography     Hybrid Journal   (Followers: 18)
The Plant Cell     Full-text available via subscription   (Followers: 23)
The Protein Journal     Hybrid Journal   (Followers: 12)
Theoretical Biology and Medical Modelling     Open Access   (Followers: 1)
Theoretical Population Biology     Hybrid Journal   (Followers: 8)
Ticks and Tick-borne Diseases     Hybrid Journal   (Followers: 5)
Tissue and Cell     Hybrid Journal   (Followers: 1)
Tissue Engineering and Regenerative Medicine     Hybrid Journal   (Followers: 7)
Tissue Engineering Part A     Hybrid Journal   (Followers: 11)
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: 5)
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: 8)
Transportation Planning and Technology     Hybrid Journal   (Followers: 8)
Tree Genetics & Genomes     Hybrid Journal   (Followers: 2)
Tree-Ring Research     Full-text available via subscription  
Trees     Hybrid Journal   (Followers: 5)
Trends in Bacteriology     Open Access  
Trends in Bioinformatics     Open Access   (Followers: 20)
Trends in Biotechnology     Full-text available via subscription   (Followers: 102)
Trends in Cell Biology     Full-text available via subscription   (Followers: 33)
Trends in Evolutionary Biology     Open Access   (Followers: 14)
Trends in Microbiology     Full-text available via subscription   (Followers: 28)
Trends in Molecular Sciences     Open Access   (Followers: 5)
Trends in Parasitology     Full-text available via subscription   (Followers: 9)
Trends in Plant Science     Full-text available via subscription   (Followers: 24)
Trends in Vector Research and Parasitology     Open Access  
Tropical Freshwater Biology     Full-text available via subscription  
Tumor Biology     Hybrid Journal   (Followers: 4)
Tumor Microenvironment and Therapy     Open Access  
Tunnelling and Underground Space Technology     Hybrid Journal   (Followers: 3)
Turkish Journal of Biology     Open Access  
Turtle and Tortoise Newsletter     Full-text available via subscription   (Followers: 1)
Ultrasound in Medicine & Biology     Full-text available via subscription   (Followers: 6)
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  
Virologica Sinica     Hybrid Journal  
Virology Journal     Open Access   (Followers: 4)
Virulence     Full-text available via subscription  
Virus Evolution     Open Access  
Virus Genes     Hybrid Journal  
Virus Research     Hybrid Journal  
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)
Weed Science     Full-text available via subscription   (Followers: 6)
Weed Technology     Full-text available via subscription   (Followers: 2)
West African Journal of Applied Ecology     Open Access  

  First | 1 2 3 4 5 6 7 8 | Last

Journal Cover Journal of Avian Biology
  [SJR: 1.201]   [H-I: 52]   [21 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  [1598 journals]
  • Genetic and paleomodelling evidence of the population expansion of the
           cattle egret Bubulcus ibis in Africa during the climatic oscillations of
           the Late Pleistocene
    • Abstract: Increasing aridity during glacial periods produced the retraction of forests and the expansion of arid and semi‐arid environments in Africa, with consequences for birds. Cattle egret (Bubulcus ibis) is a dispersive species that prefers semiarid environments and requires proximity to bodies of water. We expected that climatic oscillations led to the expansion of the range of the cattle egret during arid periods, such as the Last Maximum Glacial (LGM) and contraction of distribution during the Last Interglacial (LIG) period, resulting in contact of populations previously isolated. We investigated this hypothesis by evaluating the genetic structure and population history of 15 cattle egret breeding colonies located in West and South Africa using the mitochondrial DNA (mtDNA) control region, mtDNA ATPase 8 and 6, and an intron of nuclear gene transforming growth factor beta‐2. Occurrence data and bioclimatic information were used to generate ecological niche models of three periods (present, LGM and LIG). We used the genetic and paleomodelling data to assess the responses of the cattle egret from Africa to the climatic oscillations during the late Pleistocene. Genetic data revealed low levels of genetic differentiation, signs of isolation‐by‐distance, as well as recent increases in effective population size that started during the LGM. The observed low genetic structure may be explained by recent colonization events due to the demographic expansion following the last glacial period and by dispersal capacity of this species. The paleomodels corroborated the expansion during the LGM, and a more restricted potential distribution during the LIG. Our findinds supports the hypothesis that the species range of the cattle egret expanded during arid periods and contracted during wet periods. This article is protected by copyright. All rights reserved.
      PubDate: 2016-04-23T04:40:37.500353-05:
      DOI: 10.1111/jav.00972
       
  • Malaria infection negatively affects feather growth rate in the house
           sparrow (Passer domesticus)
    • Abstract: Birds often face various stressors during feather renewing, for example, enduring infection with blood parasites. Because nutritional resources are typically limited, especially for wild animals, when an individual allocates energy to one physiological system, there is subsequently less for other processes, thereby requiring a trade‐off. Surprisingly, potential trade‐offs between malaria infection and feather growth rate have not been experimentally considered yet. Here, we conducted three studies to investigate whether a trade‐off occurs among feather growth rate, malaria infection and host health conditions. First, we explored whether naturally infected and uninfected house sparrows differed in feather growth rate in the wild. Second, we asked whether experimental inoculation of malaria parasites and / or forcing the renewal of a tail feather. Lastly, we evaluated whether individual condition was affected by experimentally‐induced feather regrowth and / or malaria experimental infection. Our findings showed that feather growth rate was negatively affected by natural malaria infection status in free‐living birds and by experimental infection in captive birds. Furthermore, birds that did not increase body mass or hematocrit during the experimental study had slower feather growth. Together our results suggest that infection with blood parasites has more negative health effects than the growth of tail feathers and that these two processes (response to blood parasite infection and renewal of feathers) are traded‐off against each other. As such, our results highlight the role of malaria parasites as a potential mechanism driving other trade‐offs in wild passerines. This article is protected by copyright. All rights reserved.
      PubDate: 2016-04-14T01:11:34.267175-05:
      DOI: 10.1111/jav.00942
       
  • Natural and anthropogenic influences on the population structure of
           white‐tailed eagles in the Carpathian Basin and Central Europe
    • Abstract: European populations of the white‐tailed eagle (Haliaeetus albicilla) suffered a drastic decline during the 20th century. In many countries, only a few dozen breeding pairs survived or the species disappeared completely. By today, the populations have recovered, naturally or through restocking (e.g. in Scotland or the Czech Republic). In the Carpathian Basin, which is now a stronghold in southern Europe for the species in the southern part of the distribution range with more than 500 breeding pairs, only about 50 pairs survived the bottleneck. This region provides important wintering places for individuals arriving from different regions of Eurasia. In the present study, we investigated 249 DNA samples from several European countries, using 11 microsatellites and mitochondrial control region sequences (499 bp), to answer two main questions: 1) Did the Carpathian Basin population recover through local population expansion or is there a significant gene flow from more distant populations as well? 2) Does the Czech population show signs in its genetic structure of the restocking with birds of unknown origin? Our microsatellite data yielded three genetically separate lineages within Europe: northern, central and southern, the latter being present exclusively in the Carpathian Basin. Sequencing of mitochondrial DNA revealed that there is one haplotype (B12) which is not only exclusive to the Carpathian Basin but it is frequent in this population. Our results suggest that in accordance with the presumably philopatric behaviour of the species, recovery of the Carpathian Basin population was mainly local, but some of the wintering birds coming from the northern and central populations contributed to its genetic composition as well. We detected considerably higher proportions of northern birds within the Czech Republic compared to the neighbouring areas, making it likely that parents of the reintroduced birds came from northern populations. This article is protected by copyright. All rights reserved.
      PubDate: 2016-04-14T01:11:17.956074-05:
      DOI: 10.1111/jav.00938
       
  • Nest building under the risk of predation: safe nests are not always the
           best option
    • Authors: Jong Koo Lee; Steven L. Lima
      Abstract: Nest predation is a widespread demographic and evolutionary force in avian reproduction, but few studies have considered the circumstances under which birds might invest in the construction of safe nests. We examined this question using a stochastic simulation model based on a basic passerine breeding season. Nest safety functions were used to translate time invested in nest building into an increase in daily nest survival; that increase could be rapid, requiring only a few days to achieve a safe nest, or slow, taking many days to do so. The maximum achievable safety differed across nest safety functions. Given a limited length to the breeding season, a greater time investment in nest safety detracts from the time available for re‐nesting following successful or unsuccessful nesting attempts. In many circumstances, the best option is a quick‐build “minimal” nest that provides adequate support for young, but little additional safety from attacks. This is especially true for scenarios that allow for multiple nesting attempts across a season. However, relatively safe nests that can be built fairly quickly are uniformly favored options. Safe, long‐build nests are favored only when they provide a great deal of safety over other nest‐building options, but greater safety alone is not sufficient for such investment. Simulations allowing only a single nesting attempt generally favor a greater investment in nest safety. Parental survival is another important factor in nest investment. Increased danger to the parent during nest building strongly favors a low investment in nests. However, substantial investment in a safe nest is favored when that safety extends to the incubating parent. Our results provide some insight into the prevalence of seemingly unsafe, open‐cup nests across the bird world, but the range of nest types that could potentially be built by a given species is an open question. This article is protected by copyright. All rights reserved.
      PubDate: 2016-04-14T01:10:59.712585-05:
      DOI: 10.1111/jav.00958
       
  • Adaptability of a specialist predator: The effects of land use on diet
           diversification and breeding performance of Verreaux's eagles
    • Authors: M. Murgatroyd; G. Avery, L.G. Underhill, A. Amar
      Abstract: Specialist predators are generally negatively impacted by habitat change. Predators that inhabit transformed areas are usually forced to diversify their diet and this departure away from traditional resources can have negative consequences for fitness and demographic parameters. We consider this relationship as it applies to Verreaux's eagles Aquila verreauxii, which is typically considered to be a highly specialised predator of hyraxes (Procavia and Heterohyrax spp.). We investigate diet in relation to land cover in two adjacent areas of South Africa and explore the links between diet diversity, the percentage of hyrax consumed, and the breeding performance of eagles. We also examine these same patterns using data from other studies. We found that diet diversity was greater in the agriculturally developed Sandveld region compared to the natural Cederberg region. Proportions of the three main prey types were correlated with the proportion of agriculturally developed land around the nest site. Breeding performance was correlated with the diet, but not in the manner expected, with breeding productivity being greater in regions with large diet diversity and a small proportion of hyrax in the diet. We found similar patterns when placing our results into a broader geographical context using other dietary studies of Verreaux's eagles, suggesting our results were not unique to our study system. Thus, our results suggest that diet diversification does not necessarily impinge on breeding performance in the presence of adequate alternative prey resources. This research adds to the growing number of studies suggesting that some predators may be adaptable up to a threshold level of habitat transformation. These results have implications for predicting changes on such species by anthropogenic habitat transformation and highlight the potential for agriculturally developed areas to maintain a conservation value when habitat heterogeneity is maintained. This article is protected by copyright. All rights reserved.
      PubDate: 2016-04-14T01:10:41.600628-05:
      DOI: 10.1111/jav.00944
       
  • Spatial patterns of extra‐pair paternity for spotted towhees (Pipilo
           maculatus) in urban parks
    • Authors: Sarah Bartos Smith; Jenny E. Mckay, Michael T. Murphy, Deborah A. Duffield
      Abstract: The extra‐pair (EP) mating system of birds may be influenced by food resources, such that nutritionally stressed females are unable to pursue EP fertilizations (constrained female hypothesis; CFH), or that females on poor territories acquire EP fertilizations during extra‐territorial forays in search of food (mating opportunity hypothesis; MOH). Edges of urban habitat fragments are sites of apparent high food abundance for spotted towhees (Pipilo maculatus), and we used distance to habitat edge in four urban parks in Portland, OR, USA (2004‐2006), to test the CFH and MOH. EP paternity was independent of park identity and year; 44% of nests contained EP young and 26% of all young were EP. As predicted by the CFH, EP paternity was more common in nests of long‐tailed (presumably) high quality females. However, independently of tail length, younger females had more EP young than older females, a finding consistent with the MOH. Contrary to predictions of both hypotheses, the probability that a nest contained EP young was highest both at the habitat edge and habitat interior while the proportion of young in nests of EP origin (for nests with EP young) was highest at intermediate distances from habitat edge. We propose that high frequency of EP paternity among females in the interior occurred because, as predicted by the MOH, they ranged more widely in search of food and often encountered EP males. High probability of EP paternity near edges was likely unrelated to female quality. Instead, anthropogenic food sources may have attracted individuals to edges and increased encounters between potential EP mates. Simple opportunity seems likely to account for patterns of EP paternity in spotted towhees, suggesting that human altered environments have the potential to substantially affect EP mating behavior. This article is protected by copyright. All rights reserved.
      PubDate: 2016-04-13T05:46:33.09231-05:0
      DOI: 10.1111/jav.00931
       
  • Communal roosting, thermoregulatory benefits and breeding group size
           predictability in cooperatively breeding sociable weavers
    • Authors: Matthieu Paquet; Claire Doutrelant, Maxime Loubon, Franck Theron, Margaux Rat, Rita Covas
      Abstract: Extreme temperatures impose energy costs on endotherms through thermoregulation and different adaptations help individuals to cope with these conditions. In social species, communal roosting and huddling are thought to decrease the energetic requirement of thermoregulation under low temperatures. This is likely to represent an important mechanism by which individuals save energy during the coldest parts of the year and hence to represent a non‐breeding benefit of sociality. Here, we investigate the potential thermoregulatory benefits of group living in roosting groups of sociable weavers Philetairus socius, a colonial cooperatively breeding passerine that builds communally a massive nest structure with several independent chambers wherein individuals breed and roost throughout the year. To investigate the benefits of sociality during the non‐breeding season, we studied the thermal environment during roosting in relation to group size. In addition, to understand the link between non‐breeding and breeding sociality in this species we studied group size stability between the pre‐breeding and breeding periods. As expected, we found that the nest chamber's night‐time temperature is strongly related to the number of birds roosting together, especially during cold nights. Specifically, birds in larger groups spent less time below the critical thermal minimum temperature (i.e. the temperature below which energy expenditure increases substantially). They were less exposed to external temperature variations. We also found a positive relationship between the number of birds roosting during winter and the breeding group size, indicating breeding group size predictability. In cooperative breeders such as the sociable weaver, the costs and benefits of sociality are usually studied during the breeding period. This study shows that a better understanding of non‐breeding benefits of group membership and group dynamics between the non‐breeding and breeding periods are necessary for a comprehensive understanding of the benefits of sociality. This article is protected by copyright. All rights reserved.
      PubDate: 2016-04-13T05:46:30.743317-05:
      DOI: 10.1111/jav.00916
       
  • Coastal saltpans are a good alternative breeding habitat for Kentish
           plover Charadrius alexandrinus when umbrella species are present
    • Abstract: The loss and degradation of natural habitats in coastal areas worldwide has adversely affected many waterbird species, changing their breeding distribution and reducing their productivity. Anthropogenic habitats such as saltpans can provide alternative or complementary habitats for waterbirds and mitigate the increasing human impact on natural coastal habitats. Unvegetated linear paths between salt ponds are used by ground‐nesting waterbird species to breed but their linear structure may facilitate the detection of nests by predators. This negative effect may, however, be counterbalanced by the advantages of breeding in mixed colonies. To evaluate the importance and the risks of breeding in saltpans we used the Kentish plover Charadrius alexandrinus breeding in coastal saltpans of southern Portugal as a model species. Specifically, we assessed the role of nest‐site characteristics, predation and nesting proximity to species with aggressive antipredator behaviour (Black‐winged stilt Himantopus himantopus) on their breeding success. Kentish plovers selected nest‐sites on the edges of paths, with about 20% of water around the nest, and a mean visibility of more than 72 %; however nest‐site characteristics were not correlated with nesting success. Predation was the main cause of nest loss in saltpans (42%); Carrion crows Corvus corone were responsible for most daylight nest predation (58%) and Red fox (Vulpes vulpes; 73%) for night predation. An 8‐year monitoring plan of a Kentish plover population showed a linear increase in their breeding success as their breeding season increasingly overlapped with that of the Black‐winged stilt. An experiment with artificial nests showed a significant increase in the number of exposure days (7 to 12) when these nests were within close distance of Black‐winged stilt nests. Overall, our results showed that saltpans are an important alternative breeding habitat for the Kentish plover, especially for the maintenance of mixed species colonies. This article is protected by copyright. All rights reserved.
      PubDate: 2016-04-13T05:46:01.453-05:00
      DOI: 10.1111/jav.00883
       
  • Body mass change and diet switch tracked by stable isotopes indicate time
           spent at a stopover site during autumn migration in dunlins (Calidris
           alpina alpina)
    • Abstract: Birds may change their diet and foraging habitat during or after migration. Dunlins (Calidris alpina alpina) breed in the tundra of northern Europe and Russia where they feed exclusively on terrestrial prey. However, up to 80% of the flyway population uses the Wadden Sea as their first important staging site on the way to wintering grounds, feeding exclusively on marine prey. Adult birds migrate earlier than immatures and tend to fly non‐stop, whereas immatures may stage for at least a few days en route, mainly in the Baltic region. There they mostly feed on brackish water prey showing similar isotopic values compared to terrestrial prey. When they arrive in the Wadden Sea, dunlin body reserves are depleted and lower than those of individuals that have already staged for several days. We hypothesized that lighter individuals should retain a strong terrestrial isotopic blood signature, while heavier ones should show a stronger marine signature. We found a significant positive correlation between scaled mass index and carbon (δ13C) and nitrogen (δ15N) stable isotopes, reflecting the switch from terrestrial to marine prey during migration. A mixing model revealed differences in isotopic values between heavy and light adults and immatures, respectively, in relation to the isotopic prey signatures. Adults showed stronger marine signals compared with immatures, emphasizing the different modes of migration (i.e. a later departure in immatures) as well as the known spatial segregation of age classes in the Wadden Sea, i.e. adults use tidal flats distant from the shore while immatures use coastal areas influenced by terrestrial carbon sources. The results of this study demonstrate the value of scaled mass index in migratory birds as an indicator of time elapsed after diet switching following migration. Furthermore, this study extents the existing knowledge on the timing of dunlin migration by using an isotopic approach. This article is protected by copyright. All rights reserved.
      PubDate: 2016-04-13T05:45:58.516317-05:
      DOI: 10.1111/jav.00873
       
  • Egg rejection and clutch phenotype variation in the plain prinia (Prinia
           inornata)
    • Abstract: Avian hosts of brood parasites can evolve anti‐parasitic defenses to recognize and reject foreign eggs from their nests. Theory predicts that higher inter‐clutch and lower intra‐clutch variation in egg appearance facilitates hosts to detect parasitic eggs as egg‐rejection mainly depends on the appearance of the egg. Therefore, we predict that egg patterns and rejection rates will differ when hosts face different intensity of cuckoo parasitism. We tested this prediction in two populations of the plain prinia (Prinia inornata): Guangxi in mainland China with high diversity and density of cuckoo species, and Taiwan where there is only one breeding cuckoo species, the Oriental cuckoo (Cuculus optatus). As expected, egg patterns were similar within clutches but different among clutches (polymorphic eggs) in the mainland population, while the island population produced more uniform egg morphs. Furthermore, the mainland population showed a high rate of egg rejection, while the island population exhibited dramatically reduced egg grasp‐rejection ability in the absence of parasitism by the common cuckoo (Cuculus canorus). Our study suggests that prinias show lower intra‐clutch consistency in egg colour and lose egg‐rejecting ability under relaxed selection pressure from brood parasitism. This article is protected by copyright. All rights reserved.
      PubDate: 2016-04-13T05:12:01.47735-05:0
      DOI: 10.1111/jav.00786
       
  • Cross‐continental migratory connectivity and spatiotemporal
           migratory patterns in the great reed warbler
    • Abstract: Migratory connectivity describes to which degree different breeding populations have distinct (non‐overlapping) non‐breeding sites. Uncovering the level of migratory connectivity is crucial for effective conservation actions and for understanding of the evolution of local adaptations and migratory routes. Here we investigate migration patterns in a passerine bird, the great reed warbler Acrocephalus arundinaceus, over its wide Western Palearctic breeding range using geolocators from Spain, Sweden, Czech Republic, Bulgaria and Turkey. We found moderate migratory connectivity: a highly significant spatial structure in the connections between breeding and sub‐Saharan non‐breeding grounds, but at the same time a partial overlap between individual populations, particularly along the Gulf of Guinea where the majority of birds from the Spanish, Swedish and Czech populations spent their non‐breeding period. The post‐breeding migration routes were similar in direction and rather parallel for the five populations. Birds from Turkey showed the most distinctive migratory routes and sub‐Saharan non‐breeding range, with a post‐breeding migration to East Africa and, together with birds from Bulgaria, a previously unknown pre‐breeding migration over the Arabian Peninsula indicating counter‐clockwise loop migration. The distances between breeding and sub‐Saharan non‐breeding sites, as well as between first and final sub‐Saharan non‐breeding sites, differed among populations. Moreover, the total speed of migration did not differ significantly between populations during both the post‐breeding migration in autumn as well as during pre‐breeding migration in spring. There was also no significant relationship between the total speed of migration and distance between breeding and non‐breeding sites (neither post‐ nor pre‐breeding) and, surprisingly, the total speed of migration generally did not differ significantly between post‐breeding and pre‐breeding migration. Future challenges include understanding whether non‐breeding environmental conditions may have influenced the differences in migratory patterns that we observed between populations, and to which extent non‐breeding habitat fluctuations and loss may affect population sizes of migrants. This article is protected by copyright. All rights reserved.
      PubDate: 2016-03-15T07:25:35.241202-05:
      DOI: 10.1111/jav.00929
       
  • Re‐evaluating the distribution of cooperative breeding in birds: is
           it tightly linked with altriciality'
    • Authors: Ning Wang; Rebecca T. Kimball
      Abstract: The evolution of cooperative breeding (CB) in birds has aroused intensive interest for decades, largely due to the paradox that some adults forgo independent breeding to help others. While much effort has been directed at understanding the adaptive significance of CB behavior, much less effort has been spent on understanding its origin. Ligon and Burt [2004, pp5‐34, Cambridge, UK] argued that the evolution of altriciality played a key role in the origin of CB since CB occurs more frequently in altricial lineages than expected if developmental mode and CB evolved independently and that both traits arose early in the avian tree of life. We mapped presence or absence of CB, and precocial or altricial development on a recent phylogeny of all birds to re‐evaluate their conclusions. Our results suggest altriciality may be more recently derived than previously thought, and that CB species clustered in a derived land bird clade (especially within Passeriformes) where we reconstructed many gains and losses. We did find a link between cooperative breeding and altriciality. However, since CB also occurs in precocial species, has not evolved in many altricial clades, and may have evolved prior to altriciality (based on some classifications of which species have CB), it is not clear whether altriciality is linked to other factors, such as benefits to group living, that are necessary for the acquisition of CB behavior, or whether altriciality may have been a driving force in the evolution of CB itself. The relative importance of these other factors versus altriciality for the origin of CB needs to be considered. This article is protected by copyright. All rights reserved.
      PubDate: 2016-03-10T11:14:06.063493-05:
      DOI: 10.1111/jav.00869
       
  • Weak geographical structure in sperm morphology across the range of two
           willow warbler Phylloscopus trochilus subspecies in Scandinavia
    • Abstract: Sperm morphology is highly diversified among species and at higher taxonomic levels. In birds, there is also increasing evidence of geographical differentiation in sperm traits within species, especially in those with strong sperm competition. Geographical divergences in sperm traits might imply the formation of a reproductive barrier in a speciation process. Here we study sperm morphology variation of willow warblers Phylloscopus trochilus in a geographical context in Scandinavia, across the range of two subspecies that are differentiated in certain genetic markers, morphology and migratory routes. We describe geographical patterns in genotypes (two previously described single‐nucleotide polymorphism (SNP) markers and four polymorphic microsatellites); in wing length, tarsus length and body mass; and in sperm traits of 330 male willow warblers sampled at 33 localities across Norway (58o N – 69o N). Birds were on average larger and longer‐winged in the north (spp. acredula) than in the south (spp. trochilus), and showed a sigmoid change in the SNP allele frequencies and body morphology around 65o N. We found no evidence of genetic structuring in the microsatellites. There was no geographical variation in sperm traits across Norway, except that sperm heads were on average longer in the south. Sperm head length was also associated with the two SNP markers, with longer sperm heads for the southern alleles, and midpiece length was weakly associated with one of the SNP markers. Similar among‐male variances in total sperm length among the 33 sampling sites indicate uniform levels of sperm competition across Norway. We conclude that sperm morphology remains a rather undifferentiated trait between the two willow warbler subspecies in Scandinavia, which is consistent with a pattern of a shallow genetic divergence. This indicates that sperm morphology is not a reproductive barrier maintaining the narrow hybrid zone. This article is protected by copyright. All rights reserved.
      PubDate: 2016-03-10T11:12:29.54237-05:0
      DOI: 10.1111/jav.00981
       
  • IMPACT OF SPATIAL VARIATION OF A CRUCIAL PREY, THE MOLECRICKET, ON HOOPOE
           TERRITORY OCCUPANCY AND REPRODUCTION
    • Abstract: Direct benefits accrued from securing a territory of sufficient quality are important determinants of individual fitness and population persistence. Food supply is one of the main factors of animal territory quality, with spatial and temporal variation in prey availability largely dictating reproductive output and thus population dynamics. In a Swiss hoopoe population, molecrickets Gryllotalpa gryllotalpa, the most profitable prey locally, can constitute most of the food biomass delivered to chicks by parents. We first investigated the impact of molecricket prey on hoopoes' fitness‐related traits by quantifying the spatial variation in the food allocation pattern of both male and female parents to chicks across the whole population range; and second, analysed the impact of this prey on current reproduction and, using a 11 year dataset, on the temporal occupancy rate of each territory. We found considerable but spatially repeatable variation, over the years, of molecricket biomass in the diet provisioned to chicks. This spatial heterogeneity in chicks' diet composition was mirrored both in the history of territory occupancy (2002‐2012) and in current reproductive success (2012). Territories with a greater biomass of molecrickets in chicks' diet produced more fledglings in better body condition. Yet, these effects on current reproduction were exclusively demonstrated for male parents, corroborating that paternal provisioning patterns play a predominant role in hoopoe reproductive success. This study demonstrates how a single, very profitable prey species might affect spatial variation in territory settlement and individual reproductive success in a regionally endangered bird species, with potential consequences for its population dynamics and persistence. This article is protected by copyright. All rights reserved.
      PubDate: 2016-03-10T11:11:54.498216-05:
      DOI: 10.1111/jav.00990
       
  • AGE‐DEPENDENCE AND INDIVIDUAL HETEROGENEITY IN REPRODUCTIVE SUCCESS
           OF GREATER SAGE‐GROUSE
    • Authors: Danny Caudill; Michael R. Guttery, Erin Leone, Gretchen Caudill, Terry A. Messmer
      Abstract: Research on iteroparous species has shown that reproductive success may increase with age until the onset of senescence. However, from the population perspective, increased reproductive success with age could be a consequence of within‐individual variation (e.g., ageing, breeding experience, foraging ability hypotheses), between‐individual variation (e.g, individual heterogeneity, frailty, selection, delayed breeding hypotheses), or a combination thereof. We evaluated within‐ and between‐individual variation in reproductive success of greater sage‐grouse (Centrocercus urophasianus; sage‐grouse), a galliforme of conservation concern throughout western North America. We monitored female reproductive activity from 1998–2010 and used generalized linear mixed models incorporating within‐subject centering to evaluate and separate within‐ and between‐individual effects. We detected positive effects of within‐individual variation on nest initiation and success where ageing increased the likelihood of both parameters, which appears to support the breeding experience and/or foraging ability hypotheses. However, nest initiation was also affected by between‐individual variation whereby the likelihood of initiation was higher for individuals with higher mean age (i.e., survived longer), as is predicted by the frailty and selection hypotheses. Our results indicate both within‐ and between‐individual variation affect reproductive output of sage‐grouse, but the effects of each varied by measure of reproductive output. Our results corroborate previous findings that suggest population age parameters (i.e., cross‐sectional) should be interpreted with caution due to potential entanglement of within‐ and between‐individual processes. Moreover, the relative role and strength of within‐ and between‐individual processes appeared to vary by measure of reproductive output in our results, which further emphasizes the need for longitudinal analysis of age effects, even in relatively short‐lived iteroparous animals, to adequately interpret biological processes. This article is protected by copyright. All rights reserved.
      PubDate: 2016-03-10T11:10:35.861244-05:
      DOI: 10.1111/jav.00903
       
  • Characterization of the gut microbiota of migratory passerines during
           stopover along the northern coast of the Gulf of Mexico
    • Authors: William B. Lewis; Frank R. Moore, Shiao Wang
      Abstract: Although the gut microbiota is known to provide many beneficial functions to animal hosts, such as aiding in digestion, fat metabolism, and immune function, relatively little is known about the gut microbiota of passerines. Gut microbes may have both beneficial and detrimental impacts on the fitness of migratory passerines; however physiological and morphological changes associated with prolonged migratory flight may cause disruptions of the stable microbiota and potentially a loss of function. Fecal samples were collected from Swainson's Thrushes (Catharus ustulatus) and Gray Catbirds (Dumetella carolinensis) immediately after crossing the Gulf of Mexico during spring migration and before crossing during fall, and microbiota communities were analyzed using next‐generation sequencing. Microbiota communities were generally dominated by Firmicutes and Proteobacteria, with potential pathogens as well as potentially beneficial bacteria identified in all birds. Energetic condition of migrants was not significantly related to overall microbiota community structure though it cannot be conclusively stated that migratory flight does not impact the microbiota. Spring and fall migrants showed clear differences in microbiota communities, indicating that environmental factors influence the gut microbiota of these species more than host genetics. This article is protected by copyright. All rights reserved.
      PubDate: 2016-02-24T20:21:40.218635-05:
      DOI: 10.1111/jav.00954
       
  • A Synthesis of Species Interactions, Metacommunities, and the Conservation
           of Avian Diversity in Hemiboreal and Boreal Forests
    • Authors: Alexis R. Grinde; Gerald J. Niemi
      Abstract: The rate at which climate is changing in northern latitudes presents a significant threat to bird populations that rely on boreal forests. Alterations in the distributions of trees and other plants as a result of warming will alter the habitat suitability of vast regions of boreal and hemiboreal forests. Climate change associated habitat alterations along with range expansions of bird species are likely to have substantial consequences on avian communities and biodiversity. Identifying factors that contribute to species coexistence and community assembly processes at local and regional scales will facilitate predictions about the impact of climate change on avian communities in these forest ecosystems. This paper provides a comprehensive review of historic and current theories of community ecology dynamics providing a theoretical synthesis that links the evolution of species traits at the individual level, the dynamics of species interactions, and the overall maintenance of biodiversity. Integration of these perspectives is necessary to provide the scientific means to face growing environmental challenges in boreal ecosystems. This article is protected by copyright. All rights reserved.
      PubDate: 2016-02-24T20:21:12.965909-05:
      DOI: 10.1111/jav.01036
       
  • Individual variation in winter supplementary food consumption and its
           consequences for reproduction in wild birds
    • Authors: Ross A. Crates; Josh A. Firth, Damien R. Farine, Colin J. Garroway, Lindall R. Kidd, Lucy M. Aplin, Reinder Radersma, Nicole D. Milligan, Bernhard Voelkl, Antica Culina, Brecht L. Verhelst, Camilla A. Hinde, Ben C. Sheldon
      Abstract: The provision of wild birds with supplementary food has increased substantially over recent decades. While it is assumed that provisioning birds is beneficial, supplementary feeding can have detrimental ‘carry‐over’ effects on reproductive traits. Due to difficulties in monitoring individual feeding behaviour, assessing how individuals within a population vary in their exploitation of supplementary food resources has been limited. Quantifying individual consumption of supplementary food is necessary to understand the operation of carry‐over effects at the individual level. We used Radio Frequency Identification (RFID) technology and automated feeders to estimate individual consumption of supplementary winter food in a large wild population of great tits Parus major and blue tits Cyanistes caeruleus. Using these data, we identified demographic factors that explained individual variation in levels of supplementary food consumption. We also tested for carry‐over effects of supplementary food consumption on recruitment, reproductive success and a measure of survival. Individual variation in consumption of supplementary food was explained by differences between species, ages, sexes and years. Individuals were consistent across time in their usage of supplementary resources. We found no strong evidence that the extent of supplementary food consumption directly influenced subsequent fitness parameters. Such effects may instead result from supplementary food influencing population demographics by enhancing the survival and subsequent breeding of less competitive individuals, which reduce average breeding parameters and increase density‐dependent competition. Carry‐over effects of supplementary feeding are not universal and may depend upon the temporal availability of the food provided. Our study demonstrates how RFID systems can be used to examine individual‐level behaviour with minimal effects on fitness. This article is protected by copyright. All rights reserved.
      PubDate: 2016-02-24T11:03:25.163461-05:
      DOI: 10.1111/jav.00936
       
  • Mitochondrial rate variation among lineages of passerine birds
    • Authors: Jacqueline M. T. Nguyen; Simon Y. W. Ho
      Abstract: The order Passeriformes comprises the majority of extant avian species. Analyses of molecular data have provided important insights into the evolution of this diverse order. However, molecular estimates of the evolutionary and demographic timescales of passerine species have been hindered by a lack of reliable calibrations. This has led to a reliance on the application of standard substitution rates to mitochondrial DNA data, particularly rates estimated from analyses of the gene encoding cytochrome b (CYTB). To investigate patterns of rate variation across passerine lineages, we used a Bayesian phylogenetic approach to analyse the protein‐coding genes of 183 mitochondrial genomes. We found that the most commonly used mitochondrial marker, CYTB, has low variation in rates across passerine lineages. This lends support to its widespread use as a molecular clock in birds. However, we also found that the patterns of among‐lineage rate variation in CYTB are only weakly related to the evolutionary rate of the mitochondrial genome as a whole. Our analyses confirmed the presence of mutational saturation at third codon positions across the protein‐coding genes of the mitochondrial genome, reinforcing the view that these sites should be excluded in studies of deep passerine relationships. The results of our analyses have provided information that will be useful for molecular‐clock studies of passerine evolution. This article is protected by copyright. All rights reserved.
      PubDate: 2016-02-24T10:41:58.344008-05:
      DOI: 10.1111/jav.00928
       
  • Survival to independence in relation to pre‐fledging development and
           latitude in songbirds across the globe
    • Abstract: Species differ strongly in their life histories, including the probability of survival. Annual adult survival was investigated extensively in the past, whereas juvenile survival, and especially survival to independence, received much less attention. Yet, they are critical for our understanding of population demography and life‐history evolution. We investigated post‐fledging survival to independence (i.e. survival upon leaving the nest until nutritional independence) in 74 species of passerine birds worldwide based on 100 population level estimates extracted from published literature. Our comparative analyses revealed that survival to independence increased with the length of nestling period and relative fledging mass (ratio of fledging mass to adult body mass). At the same time, species with higher nest predation rates had shorter nestling periods and lower relative fledging mass. Thus, we identify an important trade‐off in life history strategies: staying longer in the nest may improve post‐fledging survival due to enhanced flight ability and sensory functions, but at the cost of a longer exposure to nest predators and increased mortality due to nest predation. Additionally, post‐fledging survival to independence did not differ between species from the northern temperate zone vs. species from the tropics and southern hemisphere. However, analyses of post‐fledging survival curves suggest that i) daily survival rates are not constant and improve quickly upon leaving the nest, and ii) species in the tropics and southern hemisphere have higher daily post‐fledging survival rates than northern temperate species. Nevertheless, due to the accumulation of mortality risk during their much longer periods of post‐fledging care, overall survival until independence is comparable across latitudes. Obtaining high‐quality demographic data across latitudes to evaluate the generality of these findings and mechanisms underlying them should be a research priority. This article is protected by copyright. All rights reserved.
      PubDate: 2016-02-24T10:41:20.257554-05:
      DOI: 10.1111/jav.00841
       
  • MHC‐I provides both quantitative resistance and susceptibility to
           blood parasites in blue tits in the wild
    • Abstract: Major histocompatibility complex (MHC) genes are central for the adaptive immune response against parasites. Here, we investigated potential associations among MHC‐I alleles and blood parasite infections in a natural breeding population of a passerine bird, the blue tit Cyanistes caeruleus, in central Spain. We screened both infection status (presence/absence of infection) and infection intensity to the pathogenic blood parasites Haemoproteus and Leucocytozoon. Three MHC‐I alleles (UA104, UA108 and UA117) were associated with higher or lower infection intensities by Leucocytozoon. Interestingly, these associations were dependent on age and were found both among young and adult birds. No MHC alleles were associated with infection intensity by Haemoproteus parasites. In addition, no significant relationships were detected between infection status by Haemoproteus and Leucocytozoon infections and MHC alleles. The very high prevalence of these two parasites in our study population (79–100%) poses challenges to identify associations with infection status and also suggests that clearance of infections may be rare. In conclusion, associations between specific MHC‐I alleles and Leucocytozoon parasites were related to either high or low infection intensities, and hence increased susceptibility or resistance to infection. This article is protected by copyright. All rights reserved.
      PubDate: 2016-02-24T10:40:45.164773-05:
      DOI: 10.1111/jav.00830
       
  • Effects of avian malaria on male behaviour and female visitation in
           lekking Blue‐crowned Manakins
    • Abstract: Avian malaria, the infection by blood parasites of the genus Plasmodium, can reduce host fitness not only through mortality, but also by impairing the expression of sexual selection traits. Although different studies highlight the association of parasitism with a decrease in host reproductive success, few studies have addressed the role of parasites in honest signalling by lekking species. Hence, it is still uncertain which fitness components are affected by parasites in these species. We investigated whether avian malaria is associated with a decrease in mating behaviour of male Blue‐crowned Manakins, Lepidothrix coronata, and whether it affects female visitation in leks of a population in the Central Amazon. Through behavioural observations, we estimated the rates of total male activity and social interaction, as well as the frequency of female visits at individual perches. We then examined if individuals were infected with Plasmodium spp. using molecular techniques. Avian malaria was associated with a decrease in male mating behaviour in each lek, and mating behaviour correlated with female visitation. Although rates of social interaction were not correlated with avian malaria among males, we observed that interacting with several individuals within a lek may be advantageous for males, as they also vocalized and displayed more, thus increasing their chances of being visited by females. Although female visitation was not associated with avian malaria in individuals or leks, it is still possible that female visitation is indirectly affected by avian malaria through the latter's effects on male activity. We suggest a role for male activity as an honest sexual signal for females. Thus, male display rate could be used by females as cue for the probability of a male being infected. This article is protected by copyright. All rights reserved.
      PubDate: 2016-02-01T05:51:46.857053-05:
      DOI: 10.1111/jav.00864
       
  • Experimental exposure to trace metals affects plumage bacterial community
           in the feral pigeon
    • Authors: M. Chatelain; A. Frantz, J. Gasparini, S. Leclaire
      Abstract: Bacteria are fundamental associates of animals, and recent studies have highlighted their major role in host behaviour, immunity or reproductive investment. Thus, any environmental factor modifying bacterial community may affect host fitness. In birds, trace metals emitted by anthropogenic activities accumulate onto the plumage where they may alter bacterial community and ultimately affect bird fitness. Although trace metals are current major environmental issues in urban habitats, their effects on feather bacterial community have never been investigated. Here, we supplemented feral pigeons (Columba livia), an emblematic urban species, with zinc and/or lead in drinking and bath water. As expected, lead and zinc supplementations modified plumage bacterial community composition. Zinc decreased bacterial load, while lead decreased bacterial richness and the frequency of preening behaviour in birds, known to regulate feather bacteria. Our results demonstrate for the first time the effects of common urban trace metals on plumage bacterial community and shed light on one of the mechanisms by which trace metals can affect bird fitness. Further studies are now needed to investigate how this effect modulates avian life history traits known to depend on plumage bacterial community. This article is protected by copyright. All rights reserved.
      PubDate: 2016-02-01T05:51:25.747332-05:
      DOI: 10.1111/jav.00857
       
  • An experimental evaluation of the effects of geolocator design and
           attachment method on between‐year survival on Whinchats Saxicola
           rubetra
    • Authors: Emma Blackburn; Malcolm Burgess, Benedictus Freeman, Alice Risely, Arin Izang, Sam Ivande, Chris Hewson, Will Cresswell
      Abstract: Data from location logging tags have revolutionised our understanding of migration ecology, but methods of tagging that do not compromise survival need to be identified. We compared resighting rates for 156 geolocator‐tagged and 316 colour ringed‐only Whinchats on their African wintering grounds after migration to and from Eastern Europe in two separate years. We experimentally varied both light stalk length (0, 5 and 10 mm) and harness material (elastic or non‐elastic nylon braid tied on, leg‐loop ‘Rappole’ harnesses) in the second year using a reasonably balanced design (all tags in the first year used an elastic harness and 10 mm light stalk). Tags weighed 0.63 g (0.01SE), representing 4.1 % of average body mass. There was no overall significant reduction in between‐year resighting rate (our proxy for survival) comparing tagged and untagged birds in either year. When comparing within tagged birds, however, using a tied harness significantly reduced resighting rate by 53 % on average compared to using an elastic harness (in all models), but stalk length effects were not statistically significant in any model considered. There was no strong evidence that the fit (relative tightness) or added tag mass affected survival, although tied tags were fitted more tightly later in the study, and birds fitted with tied tags later may have had lower survival. Overall, on a precautionary principle, deploying tags with non‐elastic tied harnesses should be avoided because the necessary fit, so as not to reduce survival, is time‐consuming to achieve and does not necessarily improve with experience. Geolocator tags of the recommended percentage of body mass fitted with elastic leg‐loop harnesses and with short light stalks can be used without survival effects in small long‐distance migrant birds. This article is protected by copyright. All rights reserved.
      PubDate: 2016-02-01T03:22:24.986858-05:
      DOI: 10.1111/jav.00871
       
  • Individual repeatability in laying behaviour does not support the
           migratory carry‐over effect hypothesis of egg‐size dimorphism
           in Eudyptes penguins
    • Authors: Kyle W. Morrison
      Abstract: Penguins of the genus Eudyptes are unique among birds in that their first‐laid A‐egg is 54–85% the mass of their second‐laid B‐egg. Although the degree of intra‐clutch egg‐size dimorphism varies greatly among the seven species of the genus, obligate brood reduction is typical of each, with most fledged chicks resulting from the larger B‐egg. Many authors have speculated upon why Eudyptes penguins have evolved and maintained a highly dimorphic 2‐egg clutch, and why it is the first‐laid egg that is so much smaller than the second, but only recently has a testable, proximate mechanism been proposed. In most species of Eudyptes penguins females appear to initiate egg‐formation at sea during return migration to breeding colonies. In macaroni penguins E. chrysolophus, females with a shorter pre‐laying interval ashore (and thus presumably greater overlap between migration and egg‐formation) lay more dimorphic eggs, suggesting a physiological conflict may constrain growth of the earlier‐initiated A‐egg. This migratory carry‐over effect hypothesis (MCEH) was tested in eastern rockhopper penguins E. chrysocome filholi on Campbell Island, New Zealand, by recording the arrival and lay dates, body sizes, and egg masses of transponder‐tagged females over two years. Females with longer pre‐laying intervals laid less dimorphic clutches, as predicted by the MCEH. However, repeated measures of individual females revealed that within‐individual variation in egg‐size dimorphism between years was unrelated to within‐individual variation in pre‐laying interval. Egg masses, and to a lesser extent egg‐size dimorphism, were highly repeatable traits related to body size and body mass. These results and a detailed consideration of the MCEH suggest that egg‐size dimorphism in Eudyptes penguins is unlikely to be caused by a migratory carry‐over effect. This article is protected by copyright. All rights reserved.
      PubDate: 2016-02-01T03:20:50.309271-05:
      DOI: 10.1111/jav.00740
       
  • The trade‐off between clutch size and egg mass in tree swallows
           (Tachycineta bicolor) is modulated by female body mass
    • Abstract: Egg production is a costly component of reproduction for female birds in terms of energy expenditure and maternal investment. Because resources are typically limited, clutch size and egg mass are expected to be constrained, and this putative trade‐off between offspring number and size is at the core of life history theory. Nevertheless, empirical evidence for this trade‐off is equivocal at best, as individual heterogeneity in resource acquisition and allocation may hamper the detection of the negative correlation between egg number and mass within populations. Here, we investigated how female body mass and landscape composition influences clutch size, egg mass, and the relationship between these two traits. To do so, we fitted linear mixed models using data from tree swallows (Tachycineta bicolor) breeding in a network of 400 nestboxes located along a gradient of agricultural intensity between 2004 and 2011. Our dataset comprised 1463 broods for clutch sizes analyses and 4371 eggs (from 847 broods laid between 2005‐2008) for egg mass analyses. Our results showed that agricultural intensity negatively impacted clutch size, but not egg mass nor the relationship between these two traits. Female mass, on the other hand, modulated the trade‐off between clutch size and egg mass. For heavier females, both traits increased jointly, without evidence of a trade‐off. However, for lighter females, there was a clear negative relationship between clutch size and egg mass. This work shows that accounting for individual heterogeneity in body mass allows the detection of a clutch size/egg mass trade‐off that would have remained undetected otherwise. Identifying habitat and individual effects on resource allocation towards reproductive traits may help bridging the gap between predictions from theory and empirical evidence on life history trade‐offs. This article is protected by copyright. All rights reserved.
      PubDate: 2016-02-01T03:13:23.782462-05:
      DOI: 10.1111/jav.00725
       
  • Estimating the abundance of burrow‐nesting species through the
           statistical analysis of combined playback and visual surveys
    • Abstract: 1. The conservation of elusive species relies on our ability to obtain unbiased estimates of their abundance trends. Many species live or breed in cavities, making it easy to define the search units (the cavity) yet hard to ascertain their occupancy. One such example is that of certain colonial seabirds like petrels and shearwaters, which occupy burrows to breed. In order to increase the chances of detection for these types of species, their sampling can be done using two independent methods to check for cavity occupancy: visual inspection, and acoustic response to a playback call. 2. This double‐detection process allows us to estimate the probability of burrow occupancy by accounting for the probability of detection associated with each method. Here we provide a statistical framework to estimate the occupancy and population size of burrow‐dwelling species. We show how to implement the method using both Maximum Likelihood and Bayesian approaches, and test its precision and bias using simulated datasets. We subsequently illustrate how to extend the method to situations where two different species may occupy the burrows, and apply it to a dataset on Wedge‐tailed shearwaters Puffinus pacificus and Tropical shearwaters P. bailloni on Aride Island, Seychelles. 3. The simulations showed that the single‐species model performed well in terms of error and bias except when detection probabilities and occupancies were very low. The two‐species model applied to shearwaters showed that detection probabilities were highly heterogeneous. The population sizes of Wedge‐tailed and Tropical shearwaters were estimated at 13,716 (95% CI: 12,909 ‐ 15,874) and 25,550 (23,667 ‐ 28,777) pairs respectively. 4. The advantages of formulating the call‐playback sampling method statistically is that it provides a framework to calculate uncertainty in the estimates and model assumptions. This method is applicable to a variety of cavity‐dwelling species where two methods can be used to detect cavity occupancy. This article is protected by copyright. All rights reserved.
      PubDate: 2016-02-01T02:44:54.365892-05:
      DOI: 10.1111/jav.00909
       
  • Plasticity in moult speed and timing in an arctic‐nesting goose
           species
    • Abstract: Environmental constraints are strong in migratory species that breed in the Arctic. In addition to breeding, Anatidae have to renew all their flight feathers during the short arctic summer. We examine how temporal constraints and climate affect the phenology of flight feather moult in the greater snow goose (Chen caerulescens atlantica), a High Arctic nesting species. We used a database of 1412 moulting adult females measured over 15 years on Bylot Island, Nunavut. Ninth (9th) primary length was used to determine the moult stage and speed of feather growth. We found a positive relationship between median annual hatching and moult initiation dates and the slope did not differ from 1. The interval between hatching and moult initiation was thus rather fixed and geese did not initiate moult earlier when reproductive phenology was delayed. Nonetheless, there was no relationship between median hatching date and the date at which birds regained flight capacity, suggesting that date of end of moult is independent of the reproductive phenology. There was a trend for an increase in the speed of flight feather growth in years with delayed hatching date. This is the most likely mechanism that could explain moult phenology adjustment in this species. Finally, we found a positive relationship between 9th primary length (corrected for inter‐annual variations) and body condition, suggesting a delay in moulting for individuals in poor condition. These results suggest that moult plasticity is primarily governed by variations in feather growth speed. This phenotypic plasticity could be necessary to complete flight feather renewal before the end of the arctic summer, independently of reproductive phenology and spring environmental conditions. Our novel results suggest possible phenological adjustments through moult speed, which was considered constant in geese until now. This article is protected by copyright. All rights reserved.
      PubDate: 2016-02-01T02:39:01.565117-05:
      DOI: 10.1111/jav.00982
       
  • Inter‐annual variability and long‐term trends in breeding
           success in a declining population of migratory swans
    • Authors: Kevin A. Wood; Julia L. Newth, Geoff M. Hilton, Bart A. Nolet, Eileen C. Rees
      Abstract: Population declines among migratory Arctic‐breeding birds are a growing concern for conservationists. To inform the conservation of these declining populations, we need to understand how demographic rates such as breeding success are influenced by combinations of extrinsic and intrinsic factors. In this study we examined inter‐annual variation and long‐term trends in two aspects of the breeding success of a migratory herbivore, the Bewick's Swan (Cygnus columbianus bewickii), which is currently undergoing a population decline: (i) the percentage of young within the wintering population and (ii) mean brood size. We used an information‐theoretic approach to test how these two measures of productivity were influenced over a 26 year period by 12 potential explanatory variables, encompassing both environmental (e.g. temperature) and intrinsic (e.g. pair‐bond duration) factors. Swan productivity exhibited sensitivity to both types of explanatory variable. Fewer young were observed on the wintering grounds in years in which the breeding period (May to September) was colder and predator (Arctic Fox) abundance was higher. The percentage of young within the wintering population also showed negative density‐dependence. Inter‐annual variance in mean swan brood size was best explained by a model comprised of the negative degree days during the swan breeding period, mean pair‐bond duration of all paired swans (i.e. mean pair duration), and an interaction between these two variables. In particular, mean pair duration had a strong positive effect on mean brood size. However, we found no long‐term directional trend in either measure of breeding success, despite the recent decline in the NW European population. Our results highlight that inter‐annual variability in breeding success is sensitive to the combined effects of both intrinsic and extrinsic factors. This article is protected by copyright. All rights reserved.
      PubDate: 2016-01-21T02:26:59.05457-05:0
      DOI: 10.1111/jav.00819
       
  • Maternal transfer of androgens in eggs is affected by food supplementation
           but not by predation risk
    • Abstract: Mothers may affect the future success of their offspring by varying allocation to eggs and embryos. Allocation may be adaptive based on the environmental conditions perceived during early breeding. We investigated the effects of food supplementation and predation risk on yolk hormone transfer in the pied flycatcher (Ficedula hypoleuca). In a food supplementation experiment, females were food‐supplemented prior to and during egg‐laying and androgen concentrations were measured throughout the laying order. Predation risk was investigated in three different studies combining both correlative data, where flycatchers bred in close proximity to two different predator species that prey upon adult flycatchers (either Tengmalm's owl, Aegolius funereus or pygmy owl, Glaucidium passerinum), and an experimental manipulation, where flycatchers were exposed to cues of a nest predator (least weasels, Mustela nivalis). Females receiving food supplementation laid eggs with lower concentrations of androstenedione (A4) than females not receiving food supplements. Yolk testosterone (T) concentration showed the same pattern but the difference was not statically significant. Testosterone (but not A4) concentration increased within clutches, from the first to the last egg, independently of the food supplementation. Females breeding under high predation risk did not differ from control females in their yolk androgen levels (A4, T or progesterone). However, concentrations of A4 tended to be lower in the proximity of pygmy owls, which could indirectly increase offspring survival after fledging. Food supplementation during egg‐laying seems to have a stronger impact on maternal transfer of androgens than predation risk. Food availability and predation risk could differentially affect the trade‐offs of androgen allocation for the offspring when raised in good vs. dangerous environments. This article is protected by copyright. All rights reserved.
      PubDate: 2016-01-21T02:26:43.252329-05:
      DOI: 10.1111/jav.00874
       
  • Cost of reproduction: a comparison of survival rates of breeding and
           non‐breeding male ortolan buntings
    • Authors: Svein Dale
      Abstract: The cost of reproduction is expected to influence survival or future reproduction. Most previous studies have assessed cost of reproduction in relation to natural and experimental variation in number of offspring produced. The ortolan bunting (Emberiza hortulana) is a passerine bird species with biparental care, and the Norwegian population of the species has an extraordinarily skewed sex ratio with only about half of the males attracting a female, and therefore provides a rare opportunity to compare survival of males that have paired and bred with that of non‐breeders (unpaired males), which have not paid a cost of reproduction. Results showed that survival rates of paired (65.0%) and unpaired (64.2%) males did not differ. However, when comparisons were restricted to paired males that definitely had nestlings, their survival rate (76.8%) was significantly higher than that of unpaired males, and the same was the case when comparisons were further restricted to paired males that had offspring recruiting to the population the next year (76.8% survived). Males breeding successfully are likely to be a biased subset of high quality males. In analyses of a subset of males that had bred successfully when young, there was no difference in survival of paired and unpaired individuals when these males were older. In conclusion, breeding male ortolan buntings did not appear to pay a cost of reproduction in terms of reduced survival to the next year compared to non‐breeding males. These results may be explained by non‐breeding males also incurring extra costs during the breeding season, and that costs of reproduction are not shared equally among sexes in the ortolan bunting and other bird species with biparental care. This article is protected by copyright. All rights reserved.
      PubDate: 2016-01-21T02:26:10.331859-05:
      DOI: 10.1111/jav.00898
       
  • Differences in shifts of wintering and breeding ranges lead to changing
           migration distances in European birds
    • Abstract: Studies on the impact of climate change on the distributions of bird species in Europe have largely focused on one season at time, especially concerning summer breeding ranges. We investigated whether migratory bird species show consistent range shifts over the past 55 years in both breeding and wintering areas or if these shifts are independent. We then analyzed whether patterns in changing migration distances of Finnish breeding birds could be explained by habitat use, phylogeny or body size. We used long‐term datasets from the Finnish ringing centre to analyze the mean wintering latitudes of 29 species of Finnish breeding birds, then used breeding distribution data to make predictions as to whether certain species were migrating shorter or longer distances based on the comparative shifts in the wintering and breeding grounds. Our data reveal species‐specific differences in changing migration distances. We show that for many species, long‐term shifts in wintering ranges have not followed the same patterns as those in the breeding range, leading to differences in migration distances over time. We conclude that species are not adjusting predictably to climate change in their wintering grounds, leading to changing migration distances in some, but not all, species breeding in Finland. This research fills an important gap in the current climate change biology literature, focusing on individuals' entire life histories and revealing new complexities in range shift patterns. This article is protected by copyright. All rights reserved.
      PubDate: 2016-01-21T02:25:54.622704-05:
      DOI: 10.1111/jav.00941
       
  • Intermediate habitat associations by hybrids may facilitate genetic
           introgression in a songbird
    • Authors: Eric M. Wood; Sara E. Barker Swarthout, Wesley M. Hochachka, Jeffery L. Larkin, Ronald W. Rohrbaugh, Kenneth V. Rosenberg, Amanda D. Rodewald
      Abstract: Hybridization or the interbreeding of genetically discrete populations or species can occur where ranges of genetically distinct units overlap. Golden‐winged Warblers (Vermivora chrysoptera), a species that has been in steady decline for decades, highlight the potential population‐level consequences of hybridization. A major factor implicated in their decline is hybridization with their sister species, the Blue‐winged Warbler (Vermivora cyanoptera), which has likely been exacerbated by historic and current land‐use practices. We examined habitat associations of Golden‐winged and Blue‐winged Warblers, phenotypic hybrids, and cryptic hybrids (i.e., mismatch between plumage phenotype and genotype as identified by mitochondrial DNA) in an area of relatively recent range overlap and hybridization in northern New York, USA. To explore the robustness of these results, we then compared the patterns from New York with habitat associations from the central Pennsylvanian Appalachian Mountains where Blue‐winged Warblers either do not occur or are in very low abundance, yet cryptic Golden‐winged Warbler hybrids are present. From 2008 to 2011, we captured 122 birds in New York and 28 in Pennsylvania and collected blood samples, which we used to determine maternal ancestry. For each bird captured, we measured territory‐level (50‐m radius circles) habitat, and later used remote‐sensing data to quantify habitat on the territories and in surrounding areas (100‐, 250‐, and 500‐m radius circles). In New York, Golden‐winged Warblers occupied structurally heterogeneous territories surrounded by homogeneously structured, contiguous deciduous forest, far from urban areas. Blue‐winged Warblers showed opposite associations, and hybrids' habitat associations were typically intermediate. In Pennsylvania, the habitat associations of Golden‐winged Warblers and their cryptic hybrids were remarkably similar to those in New York. These findings suggest that patterns of habitat occupancy by hybrids may promote contact with Golden‐winged Warblers and thus likely facilitate genetic introgression, even in areas where the parental species are not sympatric. This article is protected by copyright. All rights reserved.
      PubDate: 2016-01-18T04:29:08.411435-05:
      DOI: 10.1111/jav.00771
       
  • Helper effects in the azure‐winged magpie Cyanopica cyana in
           relation to highly‐clumped nesting pattern and high frequency of
           conspecific nest‐raiding
    • Abstract: In avian cooperative breeding systems, many benefits obtained by social pairs from the presence of helpers have been uncovered. However, until now, the factors that determine the type of assistance helpers provide and the responses of social pairs have not been well illustrated. We examined the contribution of helpers to cooperative groups and the relevant responses of dominant pairs in the azure‐winged magpie, Cyanapica cyana, which breeds on the Tibetan Plateau. We used the capture‐mark‐recapture method to identify helpers. Results showed that helpers were mostly the yearling sons of dominant pairs. They mainly contributed to the cooperative group in three ways, courtship‐feeding the incubation female, provisioning the brood, and defending the nest. For responses of dominant pairs, we unexpectedly found that clutch size was not influenced by the presence of helpers at the nest. However, cooperative groups had higher brood feeding rates than biparental nests and their feeding pattern also differed to that of the latter. Consequently, nestlings in cooperative groups had larger fledging body mass than that in biparental nests. By examining reasons for nest failure, we revealed that conspecific nest‐raiding contributed to more nest failure than any other natural predators. Because of the contribution of helpers in defending against both predators and conspecific nest‐raiders, cooperative groups had higher survival rate than biparental nests. Thus, our findings suggest that in a highly‐clumped nesting pattern, factors concerning the risk of nest predation, rather than that influencing food supply, play an important role in determining helper effects and responses of aided dominant pairs. This article is protected by copyright. All rights reserved.
      PubDate: 2016-01-18T04:22:57.886163-05:
      DOI: 10.1111/jav.00783
       
  • Comparing inferences of solar geolocation data against
           high‐precision GPS data: annual movements of a double‐tagged
           black‐tailed godwit
    • Authors: Eldar Rakhimberdiev; Nathan R. Senner, Mo A. Verhoeven, David W. Winkler, Willem Bouten, Theunis Piersma
      Abstract: Annual routines of migratory birds inferred from archival solar geolocation devices have never before been confirmed using GPS technologies. A female black‐tailed godwit Limosa limosa limosa captured on the breeding grounds in The Netherlands in 2013 and recaptured in 2014 was outfitted with both an Intigeo geolocator and an UvA‐BiTS GPS‐tracker. The GPS positions show that, after its breeding season in 2013, the godwit flew 2035 km nonstop from The Netherlands to southern Spain. It then spent the entire nonbreeding season in the southern part of the Iberian Peninsula before returning to The Netherlands the following spring, stopping for 7 days in the delta of the Ebro River in Spain, and again for a day in central Belgium. To compare the geolocation and GPS data, we analysed the geolocation data with two open‐source software packages: one using a threshold method (GeoLight) and the other a template‐fit approach (FLightR). Estimates using GeoLight, on average, deviated from the individual's true position by 495.5 ± 1031.2 km (great circle distance with equinoxes excluded), while FLightR estimates deviated by 43.3 ± 51.5 km (great circle distance with equinoxes included). Arrival and departure schedules estimated by FLightR were within 12 hours of those determined by the GPS tracker, whereas GeoLight's estimates were less precise. For the analysed track, FLightR represents an improvement over GeoLight; if true for other species and conditions, FLightR will hopefully help establish more precise and accurate uses of geolocation data in tracking studies. To aid future improvements in the analysis of solar geolocation data, we also provide the GPS and geolocation data files together with our R scripts as supplementary material. This article is protected by copyright. All rights reserved.
      PubDate: 2016-01-14T07:52:41.136478-05:
      DOI: 10.1111/jav.00891
       
  • Foraging behaviour and fuel accumulation of capital breeders during spring
           migration as derived from a combination of satellite‐ and
           ground‐based observations
    • Abstract: The migration strategy of many capital breeders is to garner body stores along the flyway at distinct stopover sites. The rate at which they can fuel is likely to be strongly influenced by a range of factors, such as physiology, food availability, time available for foraging and perceived predation. We analysed the foraging behaviour and fuel accumulation of pink‐footed geese, an Arctic capital breeder, at their mid‐ flyway spring stopover site and evaluated to what extent their behaviour and fuelling were related to physiological and external factors and how it differed from other stopovers along the flyway. We found that fuel accumulation rates of geese at the mid‐flyway site were limited by habitat availability rather than by digestive constraints. However, as the time available for foraging increased over the stopover season, geese were able to keep constant fuelling rate. Putting this in perspective, geese increased their daily net energy intake along the flyway corresponding to the increase in time available for foraging. The net energy intake per hour of foraging remained the same. Geese showed differences in their reaction to predators/disturbance between the sites, taking higher risks particularly at the final stopover site. Hence, perceived predation along the flyway may force birds to postpone the final fuel accumulation to the last stopover along the flyway. Flexibility in behaviour appears to be an important trait to ensure fitness in this capital breeder. Our findings are based on a new, improved method for estimating fuel accumulation of animals foraging in heterogeneous landscapes based on data obtained from satellite telemetry and habitat specific intake rates. This article is protected by copyright. All rights reserved.
      PubDate: 2016-01-14T07:52:24.785351-05:
      DOI: 10.1111/jav.00899
       
  • A rare study from the wintering grounds provides insight into the costs of
           malaria infection for migratory birds
    • Abstract: Malaria parasites can have strong effects on the population dynamics and evolution of migratory bird species. In many species, parasite transmission occurs on the wintering grounds, but studies to determine the consequences of infection have taken place during the breeding season, when malaria parasites circulate at chronic levels. We examined the predictors of malarial infections for great reed warblers during the northern winter in Africa, where active parasite transmission is thought to occur and naïve individuals experience acute infections. Counter to expectations, we found that winter infection intensities were lower than those encountered on the breeding grounds. One potential explanation is that reduced immune function during breeding allows parasites to persist at higher chronic intensities. We found no relationships between the incidence or intensity of infection on condition (as measured by scaled mass index, plasma metabolites, and feather corticosterone), spring migration departure dates, or home range sizes. We also tested a prediction of the Hamilton‐Zuk hypothesis and found that male ornament (song) quality was unrelated to parasitic infection status. Overall, our results provide the first evidence that long‐distance migrants captured on their wintering grounds are in the chronic stage of infection, and suggest that winter studies may fare no better than breeding studies at determining the costs of acute malarial infection for great reed warblers. This article is protected by copyright. All rights reserved.
      PubDate: 2016-01-14T07:52:08.420289-05:
      DOI: 10.1111/jav.00870
       
  • Female collared flycatchers choose neighbouring and older extra‐pair
           partners from the pool of males around their nests
    • Authors: Anais Edme; Pavel Munclinger, Milos Krist
      Abstract: Extra‐pair copulation is common among passerine birds. Females might engage in this behavior to obtain direct or indirect benefits. They may choose extra‐pair males with larger ornaments, especially if they are costly to produce. Here we studied extra‐pair paternity in the collared flycatcher. Genetic analysis allowed us to identify the presence or absence of extra‐pair young in the focal nests, and to identify extra‐pair fathers. We also identified potential males available as extra‐pair sires around the nests of females who had extra‐pair young. First, we tested the relationship between paternity in own nest and ornament size (wing patch and/or forehead patch), morphological traits and age of social males and females. Second, we compared the same suite of traits among social mates, extra‐pair males and all potential extra‐pair mates. Finally, we investigated the effect of the size of ornaments on the distance between the social nest and that of nest the extra‐pair father. Contrary to our prediction, males with larger ornaments and longer wings lost more paternity in their nests. We also found that early breeders lost less paternity in their nests. Extra‐pair males were older and had longer wings than social and potential extra‐pair males. Females mainly obtained extra‐pair mates near their nests but the distance did not vary according to ornamentation. These results could potentially be explained by differences in mate guarding strategy as older males may be more experienced in guarding their mate and attract other females more easily. More data about mate guarding and prospecting are needed to increase our understanding of mechanisms underlying the extra‐pair paternity in birds.
      PubDate: 2016-01-14T07:51:52.848313-05:
      DOI: 10.1111/jav.00839
       
  • Chemical labels differ between two closely related shearwater taxa
    • Abstract: Chemical signals may be the basis of interspecific recognition and speciation in many animals. To test whether a chemical label allowing recognition between closely related species exists in seabirds, we investigated two closely related taxa breeding sympatrically at some localities: Cory's and Scopoli's shearwaters. Procellariiform seabirds are ideal for this study because they have a well‐developed olfactory system and unequalled associated capabilities among birds. We analysed and compared the relative volatile compounds composition of the uropygial gland secretions of Cory's and Scopoli's shearwaters. As the volatile components from uropygial secretions might also provide some critical eco‐chemical information about population origin and sex, we also examined variations in the volatile compounds between populations and sexes in Cory's shearwater. The chemical data were obtained using gas chromatography–mass spectrometry techniques looking for the presence of these three particular labels: species, population and gender. We found diagnostic differences in uropygial secretions between the two species of shearwaters and smaller but significant variation between populations of Cory's shearwater in the Atlantic. No significant differences were observed between males and females. Individuals might thus use the chemical variation between species to recognize and mate with conspecifics, especially at localities where both species breed sympatrically. Geographical variation in chemical composition of uropygial secretions suggests that selective forces might vary according with locations, and might provide a key in the species recognition. Further behavioural bioassays are needed to determine whether or not these species labels are signals allowing reproductive isolation between these two taxa. Finally, one of the aims of our study was to test easier methods than freezing for storing uropygial gland secretions in the field. We describe here a new possibility for the storage of uropygial secretion samples at ambient temperature in the field, providing an alternative, simple protocols for the sampling of avian chemosignals. This article is protected by copyright. All rights reserved.
      PubDate: 2015-12-23T08:11:14.959536-05:
      DOI: 10.1111/jav.00853
       
  • Speciation in mountain refugia: phylogeography and demographic history of
           the pine siskin and black‐capped siskin complex
    • Abstract: Following Pleistocene glacial maxima, species that adapted to temperate climates in low‐latitude refugia had to modify their ranges as climate changed, expanding either latitudinally towards the poles, or altitudinally to higher elevations in mountainous regions. Within just a few thousand years, populations taking alternative routes during interglacials became isolated from each other and subjected to different selection pressures, often leading to lineage divergence and speciation. The pine siskin (Spinus pinus) is a common and widespread songbird showing relative phenotypic uniformity across the North American continent. One exception is the subspecies found in the highlands of northern Central America (S. p. perplexus), which shows marked differentiation in plumage color and shares some traits with the endemic and partly sympatric black‐capped siskin (S. atriceps), suggesting potential introgression or even a hybrid origin of perplexus. Relationships and species limits among pinus, perplexus and atriceps have been controversial for decades. We provide new molecular evidence to help resolve the evolutionary history of the group. Phylogenetic analysis of mitochondrial DNA and nuclear intron sequences revealed three distinct lineages within the complex, corresponding to: (1) S. pinus individuals from Canada through central Mexico (S. p. pinus and S. p. macropterus), (2) individuals from the highlands of Guatemala and Chiapas (S. p. perplexus), and (3) S. atriceps. Pine siskins across North America show evidence of a recent postglacial population expansion and extremely low levels of diversity and structure. In contrast, S. p. perplexus shows evidence of demographic stasis, reflecting long‐term isolation and restricted dispersal. Marked and diagnostic genetic differences among the three lineages in mtDNA and at least one intron, suggest that a hybrid origin of S. p. perplexus is unlikely, yet some degree of introgression between S. p. perplexus and S. atriceps cannot be ruled out in localities where they occur in sympatry. This article is protected by copyright. All rights reserved.
      PubDate: 2015-11-22T23:59:43.108293-05:
      DOI: 10.1111/jav.00814
       
  • Cuckoo parasitism in a cavity nesting host: near absent
           egg‐rejection in a northern redstart population under heavy apparent
           (but low effective) brood parasitism
    • Authors: Robert L. Thomson; Jere Tolvanen, Jukka T. Forsman
      Abstract: Brood parasite ‐ host systems continue to offer insights into species coevolution. A notable system is the redstart Phoenicurus phoenicurus parasitized by the “redstart‐cuckoo” Cuculus canorus gens. Redstarts are the only regular cuckoo hosts that breed in cavities, which challenges adult cuckoos in egg laying and cuckoo chicks in host eviction. We investigated parasitism in this system and found high overall parasitism rates (31.1% of 360 redstart nests), but also that only 33.1% of parasitism events (49 of 148 eggs) were successful in laying eggs into redstart nest cups. The majority of cuckoo eggs were mislaid and found on the rim of the nest; outside the nest cup. All available evidence suggests these eggs were not ejected by hosts. The effective parasitism rate was therefore only 12.8% of redstart nests. Redstarts responded to natural parasitism by deserting their nests in 13.0% of cases, compared to desertion rates of 2.8% for non‐parasitized nests. Our egg parasitism experiments found low rates (12.2%) of rejection of artificial non‐mimetic cuckoo eggs. Artificial mimetic and real cuckoo eggs added to nests were rejected at even lower rates, and were always rejected via desertion. Under natural conditions, only 21 cuckoo chicks fledged of 150 cuckoo eggs laid. Adding to this low success, is that cuckoo chicks are sometimes unable to evict all host young, and were more likely to die as a result compared to cuckoo chicks reared alone. This low success seems to be mainly due to the cavity nesting strategy of the redstart which is a challenging obstacle for the cuckoo. The redstart‐cuckoo system appears to be a fruitful model system and we suggest much more emphasis should be placed on frontline defences such as nest site selection strategies when investigating brood parasite‐host coevolution. This article is protected by copyright. All rights reserved.
      PubDate: 2015-11-22T23:59:15.215626-05:
      DOI: 10.1111/jav.00915
       
  • Causes and Characteristics of Reverse Bird Migration: an Analysis Based on
           Radar, Radio Tracking and Ringing at Falsterbo, Sweden
    • Abstract: That birds migrate in the reverse direction of the expected is a phenomenon of regular occurrence which has been observed at many sites. Here we use three different methods; tracking radar, radiotelemetry and ringing, to characterize the flights of these reverse migrants and investigate possible causes of reverse migration of nocturnally migrating passerines during autumn migration at Falsterbo peninsula, Sweden. Using these different methods we investigated both internal factors, such as age and fuel load, and external factors such as weather variables, competition and predation risk. Birds flying in the reverse direction were more likely to be lean and to be juveniles. Reverse migration was also more common with overcast skies and winds with north and east components. We did not find any effect of temperature, visibility, number of migrating sparrowhawks, or the total number of ringed birds at the site on the day of departure. We found that reverse migration is characterized by slower flight speeds (airspeed) at high altitudes and that it takes place later in the night than forward migration. This article is protected by copyright. All rights reserved.
      PubDate: 2015-11-22T23:57:48.825655-05:
      DOI: 10.1111/jav.00707
       
  • Dispersal of fungi spores by non‐specialized flower‐visiting
           birds
    • Abstract: Birds are important biotic dispersers of a wide range of propagules. Fungi spores are mainly dispersed by wind. Nevertheless there are several animals known to disperse fungi spores, which might be particularly important if spores are they delivered to particularly favourable sites i.e. directed dispersal. This may be especially important for fungi that require specific microsites such as flowers. We sampled birds for the presence of fungi spores and pollen grains during one year at two forest sites in central Portugal. We found that out of the 894 birds sampled, 131 individuals from 11 species carried spores from at least 6 morphological types, mainly during winter. The great majority of birds found to carry fungi spores was also found to carry pollen grains, suggesting that they were feeding on flowers which are the main origin of the spores. This co‐dispersion of pollen and fungi spores suggest that the latter are not randomly dispersed on the environment, but are likely to have an increased probability of being deposited on flowers propitious to fungi development. Our results suggest that directed dispersal of fungi by flower‐visiting birds might by a common and under‐appreciated phenomenon with potentially important ecological, biogeographic and even economic outcomes. This article is protected by copyright. All rights reserved.
      PubDate: 2015-11-22T23:56:50.353519-05:
      DOI: 10.1111/jav.00806
       
  • Eggshell biliverdin concentration does not sufficiently predict eggshell
           coloration
    • Authors: Michael W. Butler; Haleigh S. Waite
      Abstract: Avian eggshell coloration may have arisen due to selection on the biological, chemical, or physical properties of the pigments embedded within the eggshell, or due to selection on the coloration that emerges due to pigment deposition. Within both hypothetical frameworks, pigment‐based eggshell coloration would be related to metrics of egg quality; however, no one has evaluated the relative strength of coloration and pigment concentration in predicting egg quality. Here, we examined 66 European starling (Sturnus vulgaris) eggs and quantified eggshell biliverdin concentration (an antioxidant that produces the eggshell's blue coloration) and used 28 different coloration metrics derived from both photographic and spectrophotometric data. We also measured egg size, eggshell thickness, concentration of carotenoids in the yolk, and concentration of lysozyme in the albumen to capture variation in egg quality. We found that throughout the laying sequence, biliverdin concentration increased while eggshell thickness, yolk carotenoid concentration, and lysozyme concentration in the albumen all decreased, but this variation was not captured by any eggshell color metric. Both eggshell coloration and biliverdin concentration were negatively associated with yolk carotenoid concentration, but only eggshell biliverdin concentration was negatively associated with yolk mass. Lastly, biliverdin concentration explained, at most, only 46% of the variation for all eggshell coloration metrics. Our results suggest biliverdin concentration is a better predictor of egg quality than egg coloration in European starlings, supporting the hypothesis that eggshell pigment concentration per se may be the target of selection. This article is protected by copyright. All rights reserved.
      PubDate: 2015-11-19T08:14:03.409965-05:
      DOI: 10.1111/jav.00842
       
  • Directed flight and optimal airspeeds: homeward‐bound gulls react
           flexibly to wind yet fly slower than predicted
    • Abstract: Birds in flight are proposed to adjust their body orientation (heading) and airspeed to wind conditions adaptively according to time and energy constraints. Airspeeds in goal‐directed flight are predicted to approach or exceed maximum‐range airspeeds, which minimize transport costs (energy expenditure per unit distance) and should increase in headwinds and crosswinds. Diagnosis of airspeed adjustment is however obscured by uncertainty regarding birds’ goal‐directions, transport costs, interrelations with orientation strategy and the attainability of predicted behaviour. To address these issues, we tested whether gulls minimized transport costs through adjustment of airspeed and heading to wind conditions during extended inbound flight over water (180‐360 km) to their breeding colony, and introduce a methodology to assess transport (energy) efficiency given wind conditions. Airspeeds, heading, flight mode and energy expenditure were estimated using GPS tracking, accelerometer and wind data. Predicted flight was determined by simulating each trip according to maximum‐range airspeeds and various orientation strategies. Gulls employed primarily flapping flight (93%), and negotiated crosswinds flexibly to exploit both high altitude tailwinds and coastal soaring opportunities. We demonstrate that predicted airspeeds in heavy crosswinds depend strongly on orientation strategy and presumed preferred direction. Measured airspeeds increased with headwind and crosswind similarly to maximum‐range airspeeds based on full compensation for wind drift, yet remained ~30% lower than predicted by all strategies, resulting in slower and 30‐35% costlier flight. Interestingly, more energy could be saved through adjustment of airspeed (median 40%) than via orientation strategy (median 4%). Therefore, despite remarkably flexible reaction to wind at sea, these gulls evidently minimized neither time nor energy expenditure. However, airspeeds were possibly over‐predicted by current aerodynamic models. This study emphasizes the importance of accounting for orientation strategy when assessing airspeed adjustments to wind and indicates that either the cost or adaptive ‘currency’ of extended flight among gulls may require revision. This article is protected by copyright. All rights reserved.
      PubDate: 2015-11-19T08:13:48.98832-05:0
      DOI: 10.1111/jav.00828
       
  • The migration of the great snipe Gallinago media: intriguing variations on
           a grand theme
    • Abstract: The migration of the great snipe Gallinago media was previously poorly known. Three tracks in 2010 suggested a remarkable migratory behaviour including long and fast overland non‐stop flights (Klaassen et al. 2011). Here we present the migration pattern of Swedish male great snipes, based on 19 individuals tracked by light‐level geolocators in four different years. About half of the birds made stopover(s) in northern Europe in early autumn. They left the breeding area 15 days earlier than those which flew directly to sub‐Sahara, suggesting two distinct autumn migration strategies. The autumn trans‐Sahara flights were on average 5500 km long, lasted 64 h, and were flown at ground speeds of 25 m s‐1 (90 km h‐1). The arrival in the Sahel zone of West Africa coincided with the wet season there, and the birds stayed for on average three weeks. The birds arrived at their wintering grounds around the lower stretches of the Congo River in late September and stayed for seven months. In spring the great snipes made trans‐Sahara flights of similar length and speed as in autumn, but the remaining migration through eastern Europe was notably slow. All birds returned to the breeding grounds within one week around mid‐May. The annual cycle was characterized by relaxed temporal synchronization between individuals during the autumn‐winter period, with maximum variation at the arrival in the wintering area. Synchronization increased in spring, with minimum time variation at arrival in the breeding area. This suggests that arrival date in the breeding area is under strong stabilizing selection, while there is room for more flexibility in autumn and arrival to the wintering area. The details of the fast non‐stop flights remain to be elucidated, but the identification of the main stopover and wintering areas is important for future conservation work on this red‐listed bird species. This article is protected by copyright. All rights reserved.
      PubDate: 2015-11-17T23:17:10.153632-05:
      DOI: 10.1111/jav.00829
       
  • Evaluation of two methods for minimally invasive peripheral body
           temperature measurement in birds
    • Abstract: Body temperature (Tb) is a valuable parameter when assessing the physiological state of animals, but its widespread measurement is often constrained by methods that are invasive or require frequent recapture of animals. Alternatives based on automated remote sensing of peripheral Tb show promise, but little is known about their strengths and limitations. We measured peripheral Tb in great tits (Parus major L.) with subcutaneously implanted passive integrated transponders (PIT tags) and externally attached radio transmitters to determine repeatability of measurements, sensitivity of each method to variation in ambient temperature (Ta) and wind speed, the relationship between methods, and their ability to capture circadian variation in Tb. Repeatability of measurements by radio transmitters was high (> 80%) when readings were taken within 20 min, but reduced to 16% when measures were spaced 3.5 h apart. PIT tag data for the 3.5 h interval were more repeatable (33%) and less variable (cv). Data were affected by Ta with a stronger effect on the externally attached transmitters, but the influence of wind speed was small for both methods. There was a significant positive relationship between transmitter‐ and PIT tag temperature during both days and nights.. Both methods were equally suited to detect diel changes in peripheral Tb. However, transmitters offered longer detection distance and better temporal resolution. These qualities should be considered when deciding how to collect Tb data remotely. If properly deployed, both methods allow measurement of peripheral Tb over a wide range of natural systems and conditions in small, free‐ranging, birds. This article is protected by copyright. All rights reserved.
      PubDate: 2015-11-14T05:36:59.960872-05:
      DOI: 10.1111/jav.00845
       
  • Nest as an extended phenotype signal of female quality in the great reed
           warbler
    • Abstract: Extended phenotypes with signalling function are mostly restricted to animal taxa that use construction behaviour during courtship displays. However, they can be used also as post‐mating signals of mate quality, allowing individuals to obtain reliable information about their partners. Nest size may have such a signalling function and a lot of indirect evidence supports this view. However, direct evidence based on an experimental approach is still widely missing. Here we test the role of nest size in post‐mating signalling of mate quality in the great reed warbler (Acrocephalus arundinaceus), a passerine with female‐restricted nest‐building behaviour. Based on observational data, clutch size, nestling weight, brood size and fledglings’ propensity to return to their natal site positively correlated with nest size. Moreover, we experimentally enlarged great reed warbler nests to investigate whether this manipulation affects male investment in feeding. We found that males fed their nestlings significantly more intensively on enlarged nests than those on control nests. This suggests that nest size in this species serves as a signal of female quality or willingness to invest in reproduction and that it pays males to enhance their feeding effort according to this signal. Thus, we provide convincing evidence that animal communication takes place through the extended phenotypes and that post‐mating signalling of quality is not restricted only to males, but may function equally well in females. This article is protected by copyright. All rights reserved.
      PubDate: 2015-11-14T05:16:06.538701-05:
      DOI: 10.1111/jav.00700
       
  • The effects of heterospecifics and climatic conditions on incubation
           behavior within a mixed‐species colony
    • Authors: Peter S. Coates; Brianne E. Brussee, Roger L. Hothem, Kristy H. Howe, Michael L. Casazza, John M. Eadie
      Abstract: Parental incubation behavior largely influences nest survival, a critical demographic process in avian population dynamics, and behaviors vary across species with different life history breeding strategies. Although research has identified nest survival advantages of mixing colonies, behavioral mechanisms that might explain these effects is largely lacking. We examined parental incubation behavior using video‐monitoring techniques on Alcatraz Island, California, of black‐crowned night‐heron (Nycticorax nycticorax; hereinafter, night‐heron) in a mixed‐species colony with California gulls (Larus californicus) and western gulls (L. occidentalis). We first quantified general nesting behaviors, incubation constancy, and nest attendance, and a suite of specific nesting behaviors (i.e., inactivity, vigilance, preening, and nest maintenance) with respect to six different daily time periods. We employed linear mixed effects models to investigate environmental and temporal factors as sources of variation in incubation constancy and nest attendance using 211 nest days across three nesting seasons (2010–2012). We found incubation constancy (percent of time on the eggs) and nest attendance (percent of time at the nest) were lower for nests that were located
      PubDate: 2015-11-13T01:06:45.008553-05:
      DOI: 10.1111/jav.00900
       
  • Urban living alters moult dynamics in a passerine
    • Authors: Sydney F. Hope; Frank A. Stabile, Luke K. Butler
      Abstract: Urbanization and habitat fragmentation can alter the timing of life history events, potentially leading to phenological mismatches, carryover effects, and fitness costs. Whereas urbanization and fragmentation are known to alter important aspects of breeding in many bird species, little is known about the effects of urbanization and habitat fragmentation on moult. To investigate the effects of urbanization and fragmentation on the annual moult, we compared the moult dynamics (onset, duration, and intensity) of urban, fragmented forest, and contiguous forest populations of the Carolina Chickadee, a North American resident passerine that moults once per year immediately following the breeding season. Over three years, moult dynamics were similar in contiguous and fragmented forest populations, but wing moult started significantly earlier, and onset of moult varied less among years, in urban chickadees than in forest chickadees (fragmented and contiguous habitats pooled). Duration of wing moult did not differ between urban and forest populations, but urban birds moulted significantly fewer feathers simultaneously during peak moult, suggesting that individual feathers grew more rapidly. Our results show that urban living alters critical aspects of moult dynamics in a widespread songbird. Given the importance of moult dynamics for fitness during subsequent life history stages, and the large number of songbird species inhabiting urban areas, these results reveal previously unrecognized and potentially costly carryover effects of urban living on songbirds. This article is protected by copyright. All rights reserved.
      PubDate: 2015-11-13T01:02:53.291127-05:
      DOI: 10.1111/jav.00866
       
  • Carotenoid‐based plumage colouration is predicted by age and
           parasites in the male European serin
    • Authors: Sandra Trigo; Paulo Gama Mota
      Abstract: A fundamental assumption of theories on the evolution of sexual signals is that they should be costly to produce in order to honestly signal the quality of the sender. The expression of carotenoid‐based plumage signals is considered to be condition‐dependent, due to the role of carotenoids functioning as pigments and as health modulators. We assessed carotenoid‐based plumage colouration in relation to male condition in a free living population of male European serins, Serinus serinus during the breeding season. Male serins were trapped for morphometric and colouration measurements, during a four‐year field study, in order to evaluate the signalling value of colouration in relation to body condition and parasites level. We compared two different forms of colour quantification based on spectral data ‐ the most commonly used tristimulus colour variables and physiological models of avian colour vision ‐ and found that they were highly correlated for this species. We investigated the signalling value of male plumage colouration and it was found to be related to age and ectoparasite load. Plumage double cone and patch size were negatively related to parasites level, whereas SWS ratio was positively related to parasites and age. Colouration was also related with the time since moult. Our results indicate that the colour expression of serin's plumage is age dependent and is related, in complex ways, with the ability to cope with parasitic infection. This article is protected by copyright. All rights reserved.
      PubDate: 2015-11-13T00:46:40.472758-05:
      DOI: 10.1111/jav.00795
       
  • Nest shape explains variation in sexual dichromatism in New World
           blackbirds
    • Authors: Jonathan P. Drury; Nathan Burroughs
      Abstract: Following Charles Darwin, research on sexual dichromatism has long focused on sexual selection driving ornamentation in males. However, Alfred Russel Wallace proposed another explanation—that dichromatism evolves as a result of selection favoring crypsis in incubating females. Many recent studies suggest that evolutionary changes in sexual dichromatism often result from changes in female, in addition to male, plumage, yet the evolutionary mechanisms driving changes in female plumage remain largely unexplained. To test Wallace's hypothesis, we examined variation in sexual dichromatism and nest shape, a proxy for predation risk, among New World blackbirds (Aves: Icteridae). Phylogenetic models reveal an evolutionary correlation between sexual dichromatism and nest exposure. Specifically, we found that transitions in monochromatic lineages with exposed nests toward either concealed nests or dichromatism were common. Although this evidence supports Wallace's hypothesis that female incubation leads to selection for crypsis or concealment, we also found that transitions to monomorphism were common, even in lineages with exposed nests—a result suggestive of a role for positive selection on female ornamentation. These patterns of plumage evolution support a growing body of work emphasizing the importance of developing and testing hypotheses to explain evolutionary changes in female, as well as male, ornamentation. This article is protected by copyright. All rights reserved.
      PubDate: 2015-11-13T00:44:46.119868-05:
      DOI: 10.1111/jav.00757
       
  • A trade‐off between overheating and camouflage on shorebird eggshell
           colouration
    • Abstract: In ground‐nesting birds egg colour and appearance may have evolved due to opposite selection pressures. Pigmentation and spottiness make the eggs darker and have been suggested to improve camouflage. However darker and more spotted eggs may reach higher temperatures when not attended by adults and receiving direct sunlight, which may be lethal for embryos. Some authors suggested that this trade‐off may not exist because eggshell pigments mainly reflect in the infrared region of the solar spectrum, but have not considered that wavelengths in the visible part of the spectrum may also contribute to overheating. To test the occurrence of a trade‐off between camouflage and overheating of eggs, we took digital images to analyse colour and camouflage in 93 nests of four shorebird species (two stilts and two plovers) in two regions (tropical and mediterranean sites). We predicted that these species (closely related) may have evolved different eggshell designs depending on solar radiation, which is supposed to be stronger in the Tropics. To record egg temperatures, we placed Japanese quail eggs in natural nests of shorebirds, and registered temperatures using a datalogger. We found that darker and more spotted eggs reached higher temperatures than lighter ones, and that after controlling for environmental temperatures, eggs overheated more in the Tropics, likely because of a more intense solar radiation. We also found that tropical shorebirds’ eggshells have darker spots and lighter backgrounds. Overall, darker eggs were better camouflaged. Taken together, our results show that the benefits of increasing pigmentation of eggshell backgrounds and spottiness for a better camouflage are counteracted by the increased risks of overheating when eggs remain exposed to direct solar radiation.
      PubDate: 2015-11-03T22:21:44.355031-05:
      DOI: 10.1111/jav.00736
       
  • The role of western Mediterranean islands in the evolutionary
           diversification of the Spotted Flycatcher (Muscicapa striata), a
           long‐distance migratory passerine species
    • Abstract: We investigated the evolutionary history of the Spotted Flycatcher (Muscicapa striata), a long distance migratory passerine having a widespread range, using mitochondrial markers and nuclear introns. Our mitochondrial results reveal the existence of one insular lineage restricted to the western Mediterranean islands (Balearics, Corsica, Sardinia) and possibly to the Tyrrhenian coast of Italy that diverged from the mainland lineages around 1 Mya. Mitochondrial genetic distance between insular and mainland lineages is around 3.5%. Limited levels of shared nuclear alleles among insular and mainland populations further support the genetic distinctiveness of insular spotted flycatchers with respect to their mainland counterparts. Moreover, lack of mitochondrial haplotypes sharing between Balearic birds (M. s. balearica) and Corso‐Sardinian birds (M. s. tyrrhenica) suggest the absence of recent matrilineal gene flow between these two insular subspecies. Accordingly, we suggest that insular Spotted Flycatchers could be treated as one polytypic species (Muscicapa tyrrhenica Schiebel, 1910) that differs from M. striata in morphology, migration, mitochondrial and nuclear DNA and comprises two subspecies (the nominate and M. t. balearica, von Jordans, 1913) that diverged recently phenotypically and in mitochondrial DNA and but still share the same nuclear alleles. This study provides an interesting case‐study illustrating the crucial role of western Mediterranean islands in the evolution of a passerine showing high dispersal capabilities. Our genetic results highlight the role of glacial refugia of these islands that allowed initial allopatric divergence of insular populations. We hypothesize that differences in migratory and breeding phenology may prevent any current gene flow between insular and mainland populations of the Spotted Flycatcher that temporarily share the same insular habitats during the spring migration. This article is protected by copyright. All rights reserved.
      PubDate: 2015-11-02T07:09:24.641622-05:
      DOI: 10.1111/jav.00859
       
  • First geolocator tracks of Swedish red‐necked phalaropes reveal the
           Scandinavia‐Arabian Sea connection
    • Authors: Rob S. A. Bemmelen; Johannes Hungar, Ingrid Tulp, Raymond H. G. Klaassen
      Abstract: We studied migration and wintering patterns of a wader with a pelagic lifestyle during the non‐breeding period, the red‐necked phalarope Phalaropus lobatus. Using light‐level geolocation, we obtained three full annual tracks and one autumn migration track of male red‐necked phalaropes caught during breeding in Scandinavia. These tracks confirmed expectations that individuals from the Scandinavian population winter in the Arabian Sea. Migration was accomplished in two to four migration leaps, staging for a few days in the Gulf of Finland (autumn) or the southern Baltic Sea (spring) and for up to a month in or near the Black and Caspian Sea (autumn and spring). In addition, travel speeds suggested that only the flights between the Baltic and Black/Caspian Sea are non‐stop, and thus the birds seem to make additional short stops during the other flights. Stopover time in the Black/Caspian Sea is only 8–10 d in spring but up to 36 d in autumn, which is longer than expected if only used for pre‐migratory fattening to cover the ca 2000 km to the Gulf of Oman. After entering the Arabian Sea via the Gulf of Oman, birds dispersed over the entire presumed winter range. Winter movements appear to correspond to the spatio‐temporal patterns in primary production linked to seasonally changing monsoon winds. These are not only the first tracks of Scandinavian red‐necked phalaropes, but also the first seabird tracks in the Arabian Sea, one of the most productive and dynamic marine areas on the planet.
      PubDate: 2015-10-30T02:12:20.452544-05:
      DOI: 10.1111/jav.00807
       
  • Genetic markers validate using the natural phenotypic characteristics of
           
    • Authors: Sarah R. Hoy; Rachel E. Ball, Xavier Lambin, D. Philip Whitfield, Michael Marquiss
      Abstract: The recognition of individual animals is essential for many types of ecological research, as it enables estimates of demographic parameters such as population size, survival and reproductive rates. A popular method of visually identifying individuals uses natural variations in spot, stripe or scar markings. Although several studies have assessed the accuracy of these methods in mammals, crustaceans and fish, there have been few attempts to determine whether phenotypic characteristics are accurate when used for birds. Furthermore, even less is known about whether shed or moulted body parts can be reliably used to visually identify individuals. Here we assessed the accuracy of using phenotypic characteristics to identify avian individuals using a double‐marking experiment, whereby nine microsatellite genetic markers and natural markings on shed feathers were used to independently identify northern goshawks (Accipiter gentilis). Phenotypic and genetic identification of individuals was consistent in 94.4% (51/54) comparisons. Our results suggest that the phenotypic characteristics of shed feathers can be reliably used as a non‐invasive and relatively inexpensive technique to monitor populations of an elusive species, the northern goshawk, without having to physically re‐capture or re‐sight individuals. We posit that using natural markings on shed feathers will also be a reliable method of identifying individuals in avian species with similar phenotypic characteristics, such as other Accipiter species. This article is protected by copyright. All rights reserved.
      PubDate: 2015-10-28T21:27:47.286181-05:
      DOI: 10.1111/jav.00794
       
  • Does saline water consumption affect feeding and fuel deposition rate of a
           staging, long‐distance migrating passerine'
    • Authors: Ron Efrat; Gavriella Shani, Roee Gutman, Nir Sapir
      Abstract: To accomplish their enduring journeys, migrating birds accumulate fuel consisting mainly of lipids in stopover sites located throughout their migration routes. Fuel deposition rate (FDR) is considered a key parameter determining the speed of migration and thereby bird fitness, and recent studies have demonstrated the positive effects of fresh water consumption on the FDR of migrating blackcaps (Sylvia atricapilla). Sewage water reservoirs, characterized by higher water salinity than fresh water, were extensively built in different parts of the world and are used by birds during their travel, but their effects on wildlife and specifically on migrating birds have been largely overlooked thus far. We experimentally examined the effects of water salinity on blackcap FDR during migration. We captured birds in an autumn stopover site, transported them to the laboratory and provided them with fruits, mealworms and water of different salinity levels (0.3, 4.5 and 9‰ NaCl) for several days. We examined the effects of water salinity on the blackcaps’ diet, water consumption and FDR and found that FDR was mainly affected by fruit consumption rate and not by the water salinity levels. Water salinity nevertheless caused elevated water consumption as the birds consumed almost 3 times more saline water than fresh water per consumed fruit mass. Our work is the first to explore the consequences of saline water consumption on migrating passerines, specifically suggesting that anthropogenic alterations of habitats by sewage water treatment facilities may modulate bird nutrition and diet. This article is protected by copyright. All rights reserved.
      PubDate: 2015-10-28T21:26:05.898225-05:
      DOI: 10.1111/jav.00770
       
  • The Evolution of Sexually Dimorphic Tail Feathers Is Not Associated with
           Tail Skeleton Dimorphism
    • Authors: Ryan N. Felice; Patrick M. O'Connor
      Abstract: Sexual selection can influence the evolution of sexually dimorphic exaggerated display structures. Herein, we explore whether such costly ornamental integumentary structures evolve independently or if they are correlated with phenotypic change in the associated skeletal system. In birds, elongate tail feathers have frequently evolved in males and are beneficial as intraspecific display structures but impart a locomotor/energetic cost. Using the sexually dimorphic tail feathers of several passeriform species as a model system, we test the hypothesis that taxa with sexually dimorphic tail feathers also exhibit sexual dimorphism in the caudal skeleton that supports the muscles and integument of the tail apparatus. Caudal skeletal morphology is quantified using both geometric morphometrics and linear morphometrics across four sexually dimorphic passeriform species and four closely related monomorphic species. Sexual dimorphism is assessed using permutational MANOVA. Sexual dimorphism in caudal skeletal morphology is found only in those taxa that exhibit active functional differences in tail use between males and females. Thus, dimorphism in tail feather length is not necessarily correlated with the evolution of caudal skeletal dimorphism. Sexual selection is sufficient to generate phenotypic divergence in integumentary display structures between the sexes, but these change are not reflected in the underlying caudal skeleton. This suggests that caudal feathers and bones evolve semi‐independently from one another and evolve at different rates in response to different types of selective pressures. This article is protected by copyright. All rights reserved.
      PubDate: 2015-10-28T21:25:53.948942-05:
      DOI: 10.1111/jav.00801
       
  • Incubation temperature influences survival in a small passerine bird
    • Authors: Henrik H. Berntsen; Claus Bech
      First page: 141
      Abstract: In birds parental incubation behaviour is an important factor shaping the environmental conditions under which the embryos develop, and sub‐optimal incubation temperatures are known to negatively affect early growth and development. It is less well known if variation in incubation temperature can impose life‐long differences in individual performance and survival. In the present study we investigated the effects of incubation temperature on long‐term survival in a small passerine bird. Using our captive population of the zebra finch Taeniopygia guttata we artificially incubated eggs at three biologically relevant temperatures (35.9, 37.0 and 37.9 oC) for two‐thirds of the incubation period and then monitored individual lifespan of the hatched chicks for two and a half years. We found that individuals from eggs incubated under the lowest temperature exhibited significantly lower long‐term survival compared to those which had been incubated at the highest temperature. Our results show that incubation temperature in birds, and thus parental incubation behaviour, play an important role in shaping the life‐history trajectories of offspring. This article is protected by copyright. All rights reserved.
      PubDate: 2015-08-14T06:06:37.697525-05:
      DOI: 10.1111/jav.00688
       
  • A Test for Repertoire Matching in Eastern Song Sparrows
    • Authors: Adrienne L. DuBois; Stephen Nowicki, William A. Searcy
      First page: 146
      Abstract: Repertoire matching occurs when one songbird replies to another with a song type that the two birds share. Repertoire matching has previously been demonstrated to occur at well above chance levels in a western population of song sparrows, where it is hypothesized to serve as a low level threat in a hierarchy of aggressive signals. Here we test for repertoire matching in an eastern population of song sparrows. Previous work indicates that this eastern population differs from the western one in having lower levels of song sharing between neighboring males and in showing no association between song sharing and territory tenure. Here we confirm that males in this eastern population on average share few whole songs with their neighbors. The eastern males are familiar with their neighbors’ repertoires, as evidenced by a stronger singing response to stranger song than to neighbor song. Males in the eastern population did not repertoire match: when played an unshared song type from a specific neighbor, they did not reply with a song type shared with that neighbor more often than expected by chance or more often than in response to playback of a control song (an unshared stranger song). The results thus demonstrate a qualitative difference in vocal signaling strategies between two populations of the same species. This article is protected by copyright. All rights reserved.
      PubDate: 2015-08-18T22:06:05.390341-05:
      DOI: 10.1111/jav.00811
       
  • Does nest predation risk affect the frequency of extra‐pair
           paternity in a socially monogamous passerine'
    • Authors: Teru Yuta; Itsuro Koizumi
      First page: 153
      Abstract: While considerable variations in both the frequency of extra‐pair paternity (EPP) and the behavioral events that produce it are recognized among species, populations, individuals, and breeding attempts, the determinants of these variations are surprisingly difficult to establish. Nest predation may be one such determinant, since it is the most important source of reproductive failure, and past studies have suggested a variety of reproductive flexibilities under nest predation risk. However, despite its potentially significant effect on mating behaviors, nest predation risk has rarely been discussed in association with variations in intraspecific EPP patterns. Here, we examined the effect of naturally occurring nest predation, which varied between sites, years, and breeding attempts, on patterns of EPP in 92 broods (132 adults and 710 nestlings) of the Japanese great tit Parus major minor. We found that the frequency of extra‐pair offspring was positively correlated with the nest predation rate, along with a correlation to breeding attempts in a season, but not with other factors such as individual quality or breeding density. Under high nest‐predation risk, it may be adaptive for males to search for additional extra‐pair copulation to spread the risk of losing all offspring and to invest less in mate‐guarding, which also enables females to seek additional extra‐mating. The results of this study suggest that nest predation risk, among other factors, may significantly influence paternity allocation in birds. This article is protected by copyright. All rights reserved.
      PubDate: 2015-08-14T06:07:34.029219-05:
      DOI: 10.1111/jav.00713
       
  • Integrative taxonomy reveals Europe's rarest songbird species, the Gran
           Canaria Blue Chaffinch Fringilla polatzeki
    • First page: 159
      Abstract: The conservation of endangered taxa often critically depends on accurate taxonomic designations. The status of the Gran Canaria population of the Blue Chaffinch Fringilla t. polatzeki has not been reevaluated since the early 1900s when this taxon was described as a subspecies and combined with the much more common Tenerife Blue Chaffinch F. t. teydea in a single species. We show that multiple diagnostic differences in plumage, songs, calls and morphometrics distinguish F. t. polatzeki from F. t. teydea. Preliminary playback experiments suggest that F. t. polatzeki is able to discriminate between songs of both taxa. Along with previously reported differences in mitochondrial DNA, these findings show that the blue chaffinches on Gran Canaria and Tenerife represent two highly distinctive species: F. polatzeki and F. teydea. Gran Canaria Blue Chaffinch is Europe's rarest passerine species and should be classified as Critically Endangered. Its long‐term survival in the wild currently depends on a very small (
      PubDate: 2015-09-24T07:52:23.814083-05:
      DOI: 10.1111/jav.00825
       
  • The role of pigment based plumage traits in resolving conflicts
    • Authors: Catherine Mary Young; Kristal Elaine Cain, Nina Svedin, Patricia Ruth Yvonne Backwell, Sarah Rosalind Pryke
      First page: 167
      Abstract: The role of melanin ‘badges of status’, in male‐male competition has been well‐studied, in contrast, carotenoid based plumage has largely been examined in the context of female mate choice. Recent work has shown that carotenoid signals can also function in male‐male competition, although the functions of the two types of signals is currently unclear. Here, we examine the relationships between colouration, dominance and aggression in the crimson finch (Neochmia phaeton), a species where males have both conspicuous red carotenoid plumage and a black melanin patch. We examined the importance of carotenoid and melanin based signals in three contexts: 1) among free‐living birds interacting at a feeding station: we found that neither colour signal influenced the outcome of interactions; 2) in staged dyadic contest in captivity: we found that coloration from carotenoid pigments was positively related to the probability of winning a contest, while the size of the melanin plumage patch was not related to winning; and 3) in staged dyadic contests where male plumage colour had been masked: we found that the number of interactions required to determine dominance increased. While the underlying natural plumage colour was still important in these contests, birds with more intense carotenoid colouration were now more likely to lose. These results confirm carotenoid‐based signalling in male‐male contests. However this signal is used in conjunction with other factors such as self‐assessment and body condition. Contrary to traditional expectations, the black melanin patch was not found to be important in this context. This article is protected by copyright. All rights reserved.
      PubDate: 2015-07-30T03:51:52.176948-05:
      DOI: 10.1111/jav.00742
       
  • Condition‐dependent expression of carotenoid‐ and
           melanin‐based plumage colour of northern flicker nestlings revealed
           by manipulation of brood size
    • Authors: Annessa B. Musgrove; Karen L. Wiebe
      First page: 176
      Abstract: Carotenoid‐based colouration in feathers is widely accepted to be a reliable signal of the health of an individual, but the condition‐dependence of melanin‐based plumage ornaments has been highly debated. Using broods that were manipulated in size, we tested whether nutritional stress during rearing affected the carotenoid pigmentation in secondary feathers and the size, shape, and symmetry of melanin spots on breast plumage of northern flicker (Colaptes auratus) nestlings. Two measures of carotenoid colour (chroma and brightness) of secondary flight feathers did not vary according to brood size treatment, but in a larger dataset from the population, carotenoid chroma was positively associated with nestling mass. Nestlings from experimentally enlarged broods had smaller melanin spots than those from reduced broods, which is some of the first experimental evidence that melanin ornament size in growing nestlings is condition‐dependent. However, the shape and symmetry of the melanin breast spots was not associated with nestling mass. Sexual dimorphism was apparent in both types of pigmentation and future studies should investigate whether there are any trade‐offs for nestlings between investing in carotenoid colouration and melanisation and whether trade‐offs differ between the sexes. This article is protected by copyright. All rights reserved.
      PubDate: 2015-07-31T08:57:45.914275-05:
      DOI: 10.1111/jav.00730
       
  • Comparative demographics of a Hawaiian forest bird community
    • Authors: Alban Guillaumet; Bethany L. Woodworth, Richard J. Camp, Eben H. Paxton
      First page: 185
      Abstract: Estimates of demographic parameters such as survival and reproductive success are critical for guiding management efforts focused on species of conservation concern. Unfortunately, reliable demographic parameters are difficult to obtain for any species, but especially for rare or endangered species. Here we derived estimates of adult survival and recruitment in a community of Hawaiian forest birds, including eight native species (of which three are endangered) and two introduced species at Hakalau Forest National Wildlife Refuge, Hawaiʻi. Integrated population models (IPM) were used to link mark‐recapture data (1994‐1999) with long‐term population surveys (1987‐2008). To our knowledge, this is the first time that IPM have been used to characterize demographic parameters of a whole avian community, and provides important insights into the life history strategies of the community. The demographic data were used to test two hypotheses: (i) arthropod specialists, such as the ‘Akiapōlā‘au (Hemignathus munroi), are 'slower' species characterized by a greater relative contribution of adult survival to population growth, i.e. lower fecundity and increased adult survival; and (ii) a species’ susceptibility to environmental change, as reflected by its conservation status, can be predicted by its life history traits. We found that all species were characterized by a similar population growth rate around one, independently of conservation status, origin (native vs. non‐native), feeding guild, or life history strategy (as measured by 'slowness'), which suggested that the community had reached an equilibrium. However, such stable dynamics were achieved differently across feeding guilds, as demonstrated by a significant increase of adult survival and a significant decrease of recruitment along a gradient of increased insectivory, in support of hypothesis (i). Supporting our second hypothesis, we found that slower species were more vulnerable species at the global scale than faster ones. The possible causes and conservation implications of these patterns are discussed. This article is protected by copyright. All rights reserved.
      PubDate: 2015-08-14T06:07:16.72257-05:0
      DOI: 10.1111/jav.00756
       
  • Multi‐decadal trends in spring arrival of avian migrants to the
           central Arctic coast of Alaska: effects of environmental and ecological
           factors
    • Authors: Ward D. H; J. Helmericks, J. W. Hupp, L. McManus, M. Budde, D. C. Douglas, K. D. Tape
      First page: 197
      Abstract: Warming in the Arctic has caused the transition from winter to summer to occur weeks earlier over the last half century, yet little is known about whether avian migrants have altered their timing of arrival on breeding areas to match this earlier seasonal transition. Over a 50‐year period, we examined trends in the timing of the first arrival for 16 avian migrant species at the terminus of their northward migration along the central Arctic coast of Alaska and compared these trends to factors potentially influencing migration phenology. Date of first arrival occurred an average of 0.12 d yr‐1 or 6 d (range = 3–10 d) earlier across all species and did not differ significantly among species between 1964 and 2013. Local climatic variables, particularly temperature, had a greater effect on a species first arrival date than did large‐scale climatic predictors. First arrival date was 1.03 d earlier for every 1°C annual change in temperature, but there was nearly a 2‐fold difference in the range of responses across species (0.69–1.33 d °C‐1), implying that some species did better than others at timing their arrival with changing temperature. There was weak support for an influence of foraging strategy, migration distance, and flight path on timing of first arrival. Our findings, like others from temperate latitudes, indicate that avian migrants are responsive to changing environmental conditions, though some species appear to be more adaptive than others. This article is protected by copyright. All rights reserved.
      PubDate: 2015-09-03T04:37:23.728383-05:
      DOI: 10.1111/jav.00774
       
  • Climate variability and the timing of spring raptor migration in eastern
           North America
    • Authors: Alexis R. Sullivan; David J. Flaspohler, Robert E. Froese, Daena Ford
      First page: 208
      Abstract: Many birds have advanced their spring migration and breeding phenology in response to climate change, yet some long‐distance migrants appear constrained in their adjustments. In addition, bird species with long generation times and those in higher trophic positions may also be less able to track climate‐induced shifts in food availability. Migratory birds of prey may therefore be particularly vulnerable to climate change because: 1) most are long‐lived and have relatively low reproductive capacity, 2) many feed predominately on insectivorous passerines, and 3) several undertake annual migrations totaling tens of thousands of kilometers. Using multi‐decadal datasets for 14 raptor species observed at six sites across the Great Lakes region of North America, we detected phenological shifts in spring migration consistent with decadal climatic oscillations and global climate change. While the North Atlantic and El Niño Southern Oscillations exerted heterogeneous effects on the phenology of a few species, arrival dates more generally advanced by 1.18 days per decade, a pattern consistent with the effects of global climate change. After accounting for heterogeneity across observation sites, five of the 10 most abundant species advanced the bulk of their spring migration phenology. Contrary to expectations, we found that long‐distance migrants and birds with longer generation times tended to make the greatest advancements to their spring migration. Such results may indicate that phenotypic plasticity can facilitate climatic responses among these long‐lived predators. This article is protected by copyright. All rights reserved.
      PubDate: 2015-09-05T00:07:01.193797-05:
      DOI: 10.1111/jav.00692
       
  • Trans‐equatorial range of a land bird lineage (Aves: Rallidae) from
           tropical forests to subantarctic grasslands
    • First page: 219
      Abstract: Despite the capacity for dispersal, range size varies considerably among birds species. Many species have restricted geographic spread, whilst others routinely travel long distances to reach preferred habitat. These alternatives are well expressed amongst the rails (Rallidae) and a varying tendency for movement results in overlapping distribution patterns. Here, we examine the situation of a particular lineage, the Lewinia rails (L. mirifica, L. pectoralis and L. muelleri) that inhabit a very wide spatial and ecological range. Lewinia occurs from the Philippines, north of the equator in Oceania, to Australia and the subantarctic Auckland Islands far to the south. Allopatric distribution and differences in plumage colour result in their treatment as distinct species but our molecular analysis reveals genetic distances of less than < 1%. The genetic and phylogeographical structure in the Lewinia lineage includes shared nuclear sequence alleles and this is consistent with a callibrated multigene phylogeny suggesting trans‐hemispheric dispersal since the middle Pleistocene. Despite this recent history, available morphometric data indicates that the subantarctic population has relatively small wings for its mass, and this implies adaptation away from flight. Lewinia provides a nice example of the way dispersal and adaptation intersect over short time frames to generate diversity. This article is protected by copyright. All rights reserved.
      PubDate: 2015-09-05T00:06:45.203644-05:
      DOI: 10.1111/jav.00804
       
  • A reliable technique to quantify the individual variability of iridescence
           in birds
    • First page: 227
      Abstract: The study of iridescence in birds emerged only recently, mainly due to the difficulty inherent in quantifying its directionality. Directionality restrains color perception to a limited angle and thereby causes drastic changes in brightness when an animal is in motion. Although a versatile goniometer for quantifying iridescence has been developed recently (Meadows et al. 2011), so far, it has only been applied to measuring the highly directional iridescence in a hummingbird species. Thus, the reliability of the goniometer for species displaying more common and less directional iridescent coloration has yet to be evaluated. Additionally, two important methodological aspects remain to be assessed before this apparatus can be used confidently: 1) whether directionality, which could be subject to sexual selection, can be quantified in a repeatable way; and 2) whether the apparatus gives more precise and accurate measurements than a less complex traditional method. Using feathers collected from 271 male tree swallows (Tachycineta bicolor) over two years, we found that the goniometer provided repeatable measurements of directionality across individuals and across three body regions, namely the crown, mantle and rump. The apparatus was also more repeatable than a traditional method involving a bifurcated probe and reduced a brightness bias associated with individual differences in barbule tilt. We strongly encourage researchers to invest in this methodological change considering the multiple advantages demonstrated and to quantify the directionality of iridescence as to unveil its role in signaling and sexual selection. This article is protected by copyright. All rights reserved.
      PubDate: 2015-09-24T07:48:03.613695-05:
      DOI: 10.1111/jav.00750
       
  • Double brooding and offspring desertion in the barn owl (Tyto alba)
    • First page: 235
      Abstract: Many bird species produce two annual broods during a single breeding season. However, not all individuals reproduce twice in the same year suggesting that double brooding is condition‐dependent. In contrast to most raptors and owls, the barn owl (Tyto alba) produces two annual clutches in most worldwide distributed populations. Nevertheless, the determinants of double brooding are still poorly studied. We performed such a study in a Swiss barn owl population monitored between 1990 and 2014. The annual frequency of double brooding varied from 0 to 14% for males and 0 to 59% for females. The likelihood of double brooding was higher when individuals initiated their first clutch early rather than late in the season and when males had few rather than many offspring at the first nest. Despite the reproductive benefits of double brooding (single‐ and double‐brooded individuals produced 3.97±0.11 and 7.07±0.24 fledglings, respectively), double brooding appears to be traded off against offspring quality because at the first nest double‐brooded males produced poorer quality offspring than single‐brooded males. This might explain why females desert their first mate to produce a second brood with another male without jeopardizing reproductive success at the first nest. Furthermore, the reproductive cycle being very long in the barn owl (120 days from start of laying to offspring independence), selection may have favoured behaviours that accelerate the initiation of a second annual brood. Accordingly, half of the double‐brooded females abandoned their young offspring to look for a new partner in order to initiate the second breeding attempt, 9.48 days earlier than when producing the second brood with the same partner. We conclude that male and female barn owls adopt different reproductive strategies. Females have more opportunities to reproduce twice in a single season than males because mothers are not strictly required during the entire rearing period in contrast to fathers. A high proportion of male floaters may also encourage females to desert their first brood to re‐nest with a new male who is free of parental care duties. This article is protected by copyright. All rights reserved.
      PubDate: 2015-09-08T21:07:12.672176-05:
      DOI: 10.1111/jav.00800
       
  • Do neophobia and dietary wariness explain ecological flexibility' An
           analysis with two seed‐eating birds of contrasting habits
    • First page: 245
      Abstract: The neophobia threshold hypothesis (NTH) suggests that the acquisition and maintenance of a high behavioral and ecological flexibility in the evolutionary and adaptive history of a species is the consequence of lower levels of neophobia towards new micro‐habitats and of dietary wariness of novel foods. To test this idea we assessed the degree of neophobia and dietary wariness in two seed‐eating bird species with contrasting degrees of ecological flexibility that inhabit the central Monte desert (Argentina): a grass‐seed specialist, the many‐colored chaco‐finch, and a generalist feeder, the rufous‐collared sparrow. We expected that both species would exhibit neophobia and wariness when faced with new foraging opportunities but that the rufous‐collared sparrow would be less neophobic and less wary than the specialized many‐colored chaco‐finch. Experimental indicators of neophobia and dietary wariness included willingness to eat near novel objects and willingness to eat novel seeds, respectively. Both species showed similar levels of reluctance to novelty, although the sparrow could be slightly more reluctant than the finch. Contrary to our predictions, the sparrow was neither less hesitant nor faster or greedier than the finch. This experimental evidence does not support a negative relationship between neophobia / wariness and ecological flexibility in these two seed‐eating birds and it coincides with the growing evidence that challenges the NTH[0]. Some of our results provide support for the dangerous niche hypothesis (DNH), especially as the rufous‐collared sparrow, that feeds on more diverse and potentially dangerous food, showed higher levels of neophobia in some cases. Although the idea of neophobia and wariness being plausible causes of ecological specialization sounds attractive, the current situation calls for further research so that the causes of ecological flexibility in granivorous birds can be better understood. This article is protected by copyright. All rights reserved.
      PubDate: 2015-09-24T07:49:33.53167-05:0
      DOI: 10.1111/jav.00697
       
  • Nesting success of native and introduced forest birds on the island of
           Kaua‘i
    • Authors: Ruby L. Hammond; Lisa H. Crampton, Jeffrey T. Foster
      First page: 252
      Abstract: Forests of the Hawaiian archipelago are a global hotspot for conserving avian diversity and contain among the world's most imperiled species. Demographic studies are necessary to determine primary causes of Hawaiian forest bird population declines. We conducted research on the nesting success of multiple bird families on the island of Kaua‘i, allowing us to investigate the importance of factors related to breeding biology on forest bird declines at a community scale. Our study included two Hawaiian honeycreepers, ‘anianiau (Magumma parva) and ‘apapane (Himatione sanguinea), a native monarch flycatcher, Kaua‘i ‘elepaio (Chasiempis sclateri), and one introduced species, Japanese white‐eye (Zosterops japonicus). Data from 123 nests showed that nesting success ± SE, estimated using program MARK, was low for ‘apapane (0.23 ± 0.10), but did not vary substantially among our other study species (‘anianiau = 0.56 ± 0.09, Kaua‘i ‘elepaio = 0.63 ± 0.08, Japanese white‐eye = 0.52 ± 0.11). Causes of nest loss for 51 nest failures included nest predation (43%), unknown (25%), empty after termination with no signs of nest predation (e.g., eggshell or chick remains in nest, disheveled nest) (24%), and abandoned clutch or brood (4% each). Kaua‘i ‘elepaio suffered more than twice as many nest losses to predation compared to our other study species, but also had the highest nesting success; and, ‘apapane suffered least to nest predation, but had the lowest nesting success. Further, rates of nesting success derived in our study were relatively high compared to multi‐species studies in mainland tropics. Therefore, although nest predation accounted for the greatest proportion of nest failures, it may not be a cause of forest bird population declines in our system. We suggest that future demographic studies focus on post‐fledgling, juvenile, and adult survival, in addition to the importance of double‐brooding and renesting attempts on annual reproductive success. This article is protected by copyright. All rights reserved.
      PubDate: 2015-09-25T02:05:53.175644-05:
      DOI: 10.1111/jav.00763
       
  • Shaped by uneven Pleistocene climate: mitochondrial phylogeographic
           pattern and population history of White Wagtail Motacilla alba (Aves:
           Passeriformes)
    • First page: 263
      Abstract: We studied the phylogeography and population history of the White Wagtail Motacilla alba, which has a vast breeding range, covering areas with different Pleistocene climatic histories. The mitochondrial NADH dehydrogenase subunit II gene (ND2) and Control Region (CR) were analyzed for 273 individuals from 45 localities. Our data comprised all nine subspecies of White Wagtail. Four primary clades were inferred (M, N, SW and SE), with indications of M. grandis being nested within M. alba. The oldest split was between two haplotypes from the endemic Moroccan M. a. subpersonata (clade M) and the others, at 0.63–0.96 Mya; other divergences were at 0.31–0.38 Mya. The entire differentiation falls within the part of the Pleistocene characterized by Milankovitch cycles of large amplitudes and durations. Clade N was distributed across the northern Palearctic; clade SW in southwestern Asia plus the British Isles and was predicted by Ecological niche models (ENMs) to occur also in Central and South Europe; and clade SE was distributed in Central and East Asia. The deep divergence within M. a. subpersonata may reflect retention of ancestral haplotypes. Regional differences in historical climates have had different impacts on different populations: clade N expanded after the last glacial maximum (LGM), whereas milder Pleistocene climate of East Asia allowed clade SE a longer expansion time (since MIS 5); clade SW expanded over a similarly long time as clade SE, which is untypical for European species. ENMs supported these conclusions in that the northern part of the Eurasian continent was unsuitable during the LGM, whereas southern parts remained suitable. The recent divergences and poor structure in the mitochondrial tree contrasts strongly with the pronounced, well defined phenotypical differentiation, indicating extremely fast plumage divergence. This article is protected by copyright. All rights reserved.
      PubDate: 2015-09-24T07:55:22.544234-05:
      DOI: 10.1111/jav.00826
       
  • Complex migration and breeding strategies in an elusive bird species
           illuminated by genetic and isotopic markers
    • First page: 275
      Abstract: Unlike the annual bi‐directional movements of over 200 bird species within the Palaearctic‐Afrotropical region, irregular movements such as irruptive migration with a low degree of philopatry are reported for a variety of species depending on highly seasonal and unpredictable resources. These flexible movements allow for itinerant breeding ‐ consecutive breeding attempts in two or more geographically different regions during the same annual reproductive cycle. In order to illuminate migratory and breeding strategies of the erratic wetland species Baillon's Crake (Zapornia pusilla) across the W‐Palaearctic –Afrotropical region, we used a set of six DNA microsatellites as well as δ2Hf values of individuals sampled at one African and four European breeding sites. We investigated the degree of genetic population structure within and among different sites and assigned individuals′ feathers of unknown origin to their probable moulting (hence breeding) site using a likelihood approach. We found three genetic clusters, differentiating into one “European” and two “African” populations. Connectivity between the sampling sites was probable as genetic “African” individuals were found in breeding conditions in Europe and vice versa. Likewise, assigned moulting locations based on δ2H isoscapes suggested trans‐continental movements as well as moulting and possibly breeding by the same individual both in African and European breeding grounds. Both isotopic and genetic data reveal the Baillon's Crake pursue a complex migration and breeding strategy, allowing as well for irruptive movements and itinerant breeding across the W‐Palaearctic‐Afrotropical region. However, a better knowledge about the species’ distribution as well as a more comprehensive data set, including samples from the Southern and Eastern boundaries of the distribution area would be necessary to improve the spatial resolution to the precision required to unambiguously infer migration directions and extent of exchange between African and European breeding grounds. This article is protected by copyright. All rights reserved.
      PubDate: 2015-09-24T07:46:24.406278-05:
      DOI: 10.1111/jav.00751
       
  • Chemical defence in avian brood parasites: production and function of
           repulsive secretions in common cuckoo chicks
    • First page: 288
      Abstract: The use of active chemical defence against predators is relatively rare in birds. Among others, it has been reported for some members of family Cuculidae whose chicks, when threatened, expel dark foul‐smelling liquid from their cloaca. Apart from the brood parasitic great spotted cuckoo Clamator glandarius, however, this phenomenon has not yet been systematically studied in any other cuckoo species. Here we investigated the repellent behaviour in the evicting brood parasite, the common cuckoo Cuculus canorus, parasitizing the great reed warbler Acrocephalus arundinaceus. We explored whether production of secretions varies with chick age or size, and tested its presumed repellent function against various types of predators. We found that the production of secretions commenced at the age of approximately eight days, then gradually increased and decreased again shortly before fledging. Furthermore, we experimentally confirmed a more intensive repellent effect of the secretions on mammal predators than on avian predators, such as raptors and owls. The secretions have, however, no effect on corvid predators, probably because these scavengers often consume malodorous food. Further experimental studies together with phylogenetic comparative analyses are needed to elucidate the origin and function of this intriguing phenomenon both in parasitic and non‐parasitic cuckoos. This article is protected by copyright. All rights reserved.
      PubDate: 2015-08-14T06:06:55.628599-05:
      DOI: 10.1111/jav.00785
       
 
 
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