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ZOOLOGY (140 journals)                  1 2     

Acta Herpetologica     Open Access   (Followers: 3)
Acta Theriologica     Full-text available via subscription   (Followers: 6)
Acta Zoologica     Hybrid Journal   (Followers: 3)
Acta Zoologica Cracoviensia     Free   (Followers: 2)
Acta zoológica mexicana     Open Access  
Advances in Zoology     Open Access  
Advances in Zoology and Botany     Open Access  
African Invertebrates     Open Access  
African Journal of Herpetology     Full-text available via subscription   (Followers: 1)
African Journal of Wildlife Research     Full-text available via subscription   (Followers: 1)
African Zoology     Hybrid Journal   (Followers: 5)
American Journal of Zoological Research     Open Access  
animal     Hybrid Journal   (Followers: 3)
Animal Behaviour     Hybrid Journal   (Followers: 99)
Animal Biology     Hybrid Journal   (Followers: 7)
Animal Biology & Animal Husbandry     Open Access   (Followers: 4)
Animal Biotelemetry     Open Access   (Followers: 1)
Animal Genetics     Hybrid Journal   (Followers: 6)
Animal Migration     Open Access   (Followers: 2)
Animal Studies Journal     Open Access   (Followers: 5)
Annales Zoologici     Full-text available via subscription  
Annales Zoologici Fennici     Open Access  
Annals of Animal Science     Open Access   (Followers: 1)
Annals of the Ditsong National Museum of Natural History     Full-text available via subscription  
Annual Review of Animal Biosciences     Full-text available via subscription   (Followers: 4)
Anthrozoos : A Multidisciplinary Journal of The Interactions of People & Animals     Hybrid Journal   (Followers: 6)
Applied Animal Behaviour Science     Hybrid Journal   (Followers: 17)
Applied Entomology and Zoology     Partially Free   (Followers: 2)
Aquatic Mammals     Full-text available via subscription   (Followers: 8)
Aquatic Sciences     Hybrid Journal   (Followers: 12)
Arquivos de Ciências Veterinárias e Zoologia da UNIPAR     Open Access  
Arthropod Management Tests     Hybrid Journal   (Followers: 2)
Asian Journal of Animal and Veterinary Advances     Open Access   (Followers: 6)
Australian Journal of Zoology     Hybrid Journal  
Bangladesh Journal of Zoology     Open Access  
Bioacoustics : The International Journal of Animal Sound and its Recording     Partially Free   (Followers: 3)
Bird Conservation International     Hybrid Journal   (Followers: 18)
Bird Study     Full-text available via subscription   (Followers: 21)
Brazilian Journal of Veterinary Research and Animal Science     Open Access   (Followers: 8)
British Birds     Full-text available via subscription   (Followers: 21)
Bulletin of the Museum of Comparative Zoology     Full-text available via subscription   (Followers: 2)
Canadian Journal of Animal Science     Full-text available via subscription   (Followers: 3)
Canadian Journal of Zoology     Full-text available via subscription   (Followers: 14)
Contributions to Zoology     Open Access   (Followers: 3)
Der Zoologische Garten     Full-text available via subscription   (Followers: 2)
Ecology of Freshwater Fish     Hybrid Journal   (Followers: 16)
Edentata     Open Access  
European Journal of Taxonomy     Open Access   (Followers: 3)
Euscorpius     Open Access  
EvoDevo     Open Access   (Followers: 1)
Fieldiana Zoology     Full-text available via subscription  
Fish and Fisheries     Hybrid Journal   (Followers: 25)
Frontiers in Zoology     Open Access   (Followers: 7)
Graellsia     Open Access  
Herpetology Notes     Open Access  
Hystrix, the Italian Journal of Mammalogy     Open Access  
i-Perception     Open Access   (Followers: 2)
Iheringia. Série Zoologia     Open Access  
In Vitro Cellular & Developmental Biology - Animal     Hybrid Journal   (Followers: 1)
Integrative Zoology     Hybrid Journal  
International Journal of Odonatology     Hybrid Journal   (Followers: 1)
International Journal of Zoological Research     Open Access   (Followers: 1)
International Journal of Zoology     Open Access   (Followers: 2)
International Studies on Sparrows     Open Access  
International Zoo Yearbook     Hybrid Journal   (Followers: 2)
Invertebrate Reproduction & Development     Hybrid Journal   (Followers: 3)
Italian Journal of Animal Science     Open Access   (Followers: 2)
Italian Journal of Zoology     Hybrid Journal   (Followers: 1)
Journal of Agrobiology     Open Access   (Followers: 3)
Journal of Animal Ecology     Hybrid Journal   (Followers: 51)
Journal of Animal Physiology and Animal Nutrition     Hybrid Journal   (Followers: 5)
Journal of Apicultural Science     Open Access   (Followers: 1)
Journal of Applied Animal Research     Hybrid Journal   (Followers: 1)
Journal of Basic & Applied Zoology : Physiology     Open Access   (Followers: 1)
Journal of Experimental Zoology Part A: Ecological Genetics and Physiology     Hybrid Journal   (Followers: 3)
Journal of Experimental Zoology Part B : Molecular and Developmental Evolution     Hybrid Journal   (Followers: 1)
Journal of Freshwater Ecology     Hybrid Journal   (Followers: 14)
Journal of Herpetology     Full-text available via subscription   (Followers: 6)
Journal of Insects     Open Access  
Journal of Venomous Animals and Toxins     Open Access   (Followers: 4)
Journal of Venomous Animals and Toxins including Tropical Diseases     Open Access  
Journal of Wildlife Management     Hybrid Journal   (Followers: 32)
Journal of Zoo and Aquarium Research     Open Access   (Followers: 2)
Journal of Zoological Systematics and Evolutionary Research     Hybrid Journal   (Followers: 3)
Journal of Zoology     Hybrid Journal   (Followers: 19)
Laboratory Animals     Hybrid Journal   (Followers: 11)
Mammalia     Hybrid Journal   (Followers: 6)
Marine Ecology Progress Series MEPS     Hybrid Journal   (Followers: 19)
Memorias de la Conferencia Interna en Medicina y Aprovechamiento de Fauna Silvestre, Exótica y no Convencional     Open Access  
Monographs of the Transvaal Museum     Full-text available via subscription  
Natural History Sciences     Hybrid Journal  
Neotropical Primates     Open Access   (Followers: 1)
New Zealand Journal of Zoology     Hybrid Journal   (Followers: 2)
Papéis Avulsos de Zoologia     Open Access  
Parasite     Open Access   (Followers: 4)
Physiological and Biochemical Zoology     Full-text available via subscription   (Followers: 5)
Polish Journal of Entomology     Open Access   (Followers: 4)
Primate Biology     Open Access  
Protist Genomics     Open Access  
Redia : Journal of Zoology     Open Access  

        1 2     

Journal Cover Journal of Animal Ecology
  [SJR: 3.074]   [H-I: 102]   [51 followers]  Follow
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 0021-8790 - ISSN (Online) 1365-2656
   Published by John Wiley and Sons Homepage  [1598 journals]
  • Within guild co‐infections influence parasite community membership:
           a longitudinal study in African Buffalo
    • Authors: Brian Henrichs; Marinda C. Oosthuizen, Milana Troskie, Erin Gorsich, Carmen Gondhalekar, Brianna Beechler, Vanessa O. Ezenwa, Anna E. Jolles
      Abstract: 1.Experimental studies in laboratory settings have demonstrated a critical role of parasite interactions in shaping parasite communities. The sum of these interactions can produce diverse effects on individual hosts as well as influence disease emergence and persistence at the population level. 2.A predictive framework for the effects of parasite interactions in the wild remains elusive, largely because of limited longitudinal or experimental data on parasite communities of free‐ranging hosts. 3.This four year study followed a community of haemoparasites in free‐ranging African buffalo (Syncerus caffer). We detected infection by 11 haemoparasite species using PCR‐based diagnostic techniques, and analyzed drivers of infection patterns using generalized linear mixed models to understand the role of host characteristics and season on infection likelihood. We tested for (1) effects of co‐infection by other haemoparasites (within guild) and (2) effects of parasites infecting different tissue types (across guild). 4.We found that within guild co‐infections were the strongest predictors of haemoparasite infections in the buffalo; but that seasonal and host characteristics also had important effects. In contrast, the evidence for across‐guild effects of parasites utilizing different tissue on haemoparasite infection was weak. 5.These results provide a nuanced view of the role of co‐infections in determining haemoparasite infection patterns in free living mammalian hosts. Our findings suggest a role for interactions among parasites infecting a single tissue type in determining infection patterns. This article is protected by copyright. All rights reserved.
      PubDate: 2016-04-16T06:25:42.43273-05:0
      DOI: 10.1111/1365-2656.12535
  • Good Reasons To Leave Home: Proximate Dispersal Cues In A Social Spider
    • Abstract: 1.Natal dispersal is a successful tactic under a range of conditions in spite of significant costs. Habitat quality is a frequent proximate cause of dispersal, and studies have shown that dispersal increases both when natal habitat quality is good or poor. In social species kin competition, favoring dispersal, may be balanced by the benefits of group living, favoring philopatry. 2.We investigated the effect of changes in the local environment on natal dispersal of adult females in a social spider species, Stegodyphus dumicola (Araneae, Eresidae), with a flexible breeding system, where females can breed either within the colony or individually following dispersal. 3.We manipulated foraging opportunities in colonies by either removing the capture webs or by adding prey and recorded the number of dispersing females around each focal colony, and their survival and reproductive success. We predicted that increasing kin competition should increase dispersal of less‐competitive individuals, while reducing competition could cause either less dispersal (less competition) or more dispersal (a cue indicating better chances to establish a new colony). 4.Dispersal occurred earlier and at a higher rate in both food‐augmented and web‐removal colonies than in control colonies. Fewer dispersing females survived and reproduced in the web‐removal group than in the control or food augmented groups. 5.The results support our prediction that worsening conditions in web‐removal colonies favor dispersal, whereby increased kin competition and increased energy expenditure on web renewal cause females to leave the natal colony. By contrast, prey augmentation may serve as a habitat‐quality cue; when the surrounding habitat is expected to be of high quality, females assess the potential benefit of establishing a new colony to be greater than the costs of dispersal. This article is protected by copyright. All rights reserved.
      PubDate: 2016-04-16T06:20:42.722507-05:
      DOI: 10.1111/1365-2656.12534
  • Dietary niche constriction when invaders meet natives: evidence from
           freshwater decapods
    • Authors: Michelle C. Jackson; Jonathan Grey, Katie Miller, J Robert Britton, Ian Donohue
      Abstract: 1.Invasive species are a key driver of global environmental change, with frequently strong negative consequences for native biodiversity and ecosystem processes. Understanding competitive interactions between invaders and functionally similar native species provides an important benchmark for predicting the consequences of invasion. However, even though having a broad dietary niche is widely considered a key factor determining invasion success, little is known about the effects of competition with functionally similar native competitors on the dietary niche breadths of invasive species. 2.We used a combination of field experiments and field surveys to examine the impacts of competition with a functionally similar native crab species on the population densities, growth rates and diet of the globally widespread invasive red swamp crayfish in an African river ecosystem. 3.The presence of native crabs triggered significant dietary niche constriction within the invasive crayfish population. Further, growth rates of both species were reduced significantly, and by a similar extent, in the presence of one another. In spite of this, crayfish maintained positive growth rates in the presence of crabs, whereas crabs lost mass in the presence of crayfish. Consequently, over the three year duration of the study, crab abundance declined at those sites invaded by the crayfish, becoming locally extinct at one. 4.The invasive crayfish had a dramatic effect on ecosystem structure and functioning, halving benthic invertebrate densities and increasing decomposition rates four‐fold compared to the crabs. This indicates that replacement of native crabs by invasive crayfish likely alters the structure and functioning of African river ecosystems significantly. 5.This study provides a novel example of the constriction of the dietary niche of a successful invasive population in the presence of competition from a functionally similar native species. This finding highlights the importance of considering both environmental and ecological contexts in order to predict and manage the impacts of invasive species on ecosystems. This article is protected by copyright. All rights reserved.
      PubDate: 2016-04-16T06:05:40.590434-05:
      DOI: 10.1111/1365-2656.12533
  • Interactions between plants and primates shape community diversity in a
           rainforest in Madagascar
    • Authors: James Paul Herrera
      Abstract: 1.Models of ecological community assembly predict how communities of interacting organisms may be shaped by abiotic and biotic factors. Competition and environmental filtering are the predominant factors hypothesized to explain community assembly. 2.This study tested the effects of habitat, phylogenetic and phenotypic trait predictors on species co‐occurrence patterns and abundances, with the endemic primates of Madagascar as an empirical system. 3.The abundance of 11 primate species was estimated along gradients of elevation, food resource abundance, and anthropogenic habitat disturbance at local scales in southeast Madagascar. Community composition was compared to null models to test for phylogenetic and functional structure, and the effects of phylogenetic relatedness of co‐occurring species, their trait similarity, and environmental variables on species’ abundances were tested using mixed models and quantile regressions. 4.Resource abundance was the strongest predictor of community structure. Where food tree abundance was high, closely related species with similar traits dominated communities. High elevation communities with lower food tree abundance consisted of species that were distantly related and had divergent traits. Closely related species had dissimilar abundances where they co‐occurred, partially driven by trait dissimilarity, indicating character displacement. 5.By integrating local‐scale variation in primate community composition, evolutionary relatedness and functional diversity, this study found strong evidence that community assembly in this system can be explained by competition and character displacement along ecological gradients. This article is protected by copyright. All rights reserved.
      PubDate: 2016-04-16T06:00:47.301212-05:
      DOI: 10.1111/1365-2656.12532
  • Energy storage and fecundity explain deviations from ecological
           stoichiometry predictions under global warming and size‐selective
    • Authors: Chao Zhang; Mieke Jansen, Luc De Meester, Robby Stoks
      Abstract: 1.A key challenge for ecologists is to predict how single and joint effects of global warming and predation risk translate from the individual level up to ecosystem functions. Recently, stoichiometric theory linked these levels through changes in body stoichiometry, predicting that both higher temperatures and predation risk induce shifts in energy storage (increases in C‐rich carbohydrates and reductions in N‐rich proteins) and body stoichiometry (increases in C:N and C:P). This promising theory, however, is rarely tested and assumes that prey will divert energy away from reproduction under predation risk, while under size‐selective predation, prey instead increase fecundity. 2.We exposed the water flea Daphnia magna to 4 °C warming and fish predation risk to test whether C‐rich carbohydrates increase and N‐rich proteins decrease and as a result C:N and C:P increase under warming and predation risk. 3.Unexpectedly, warming decreased body C:N, which was driven by reductions in C‐rich fat and sugar contents while the protein content did not change. This reflected a trade‐off where the accelerated intrinsic growth rate under warming occurred at the cost of a reduced energy storage. Warming reduced C:N less and only increased C:P and N:P in the fish‐period Daphnia. These evolved stoichiometric responses to warming were largely driven by stronger warming‐induced reductions in P than in C and N and could be explained by the better ability to deal with warming in the fish‐period Daphnia. 4.In contrast to theory predictions, body C:N decreased under predation risk due to a strong increase in the N‐rich protein content that offset the increase in C‐rich fat content. The higher investment in fecundity (more N‐rich eggs) under predation risk contributed to this stronger increase in protein content. Similarly, the lower body C:N of pre‐fish Daphnia also matched their higher fecundity. 5.Warming and predation risk independently shaped body stoichiometry, largely by changing levels of energy storage molecules. Our results highlight that two widespread patterns, the trade‐off between rapid development and energy storage and the increased investment in reproduction under size‐selective predation cause predictable deviations from current ecological stoichiometry theory. This article is protected by copyright. All rights reserved.
      PubDate: 2016-04-15T00:36:29.495401-05:
      DOI: 10.1111/1365-2656.12531
  • Widespread correlations between climatic niche evolution and species
           diversification in birds
    • Authors: Christopher R. Cooney; Nathalie Seddon, Joseph A. Tobias
      Abstract: 1.The adaptability of species’ climatic niches can influence the dynamics of colonisation and gene flow across climatic gradients, potentially increasing the likelihood of speciation, or reducing extinction in the face of environmental change. However, previous comparative studies have tested these ideas using geographically, taxonomically and ecologically restricted samples, yielding mixed results, and thus the processes linking climatic niche evolution with diversification remain poorly understood. 2.Focusing on birds, the largest and most widespread class of terrestrial vertebrates, we test whether variation in species diversification among clades is correlated with rates of climatic niche evolution, and the extent to which these patterns are modified by underlying gradients in biogeography and species’ ecology. 3.We quantified climatic niches, latitudinal distribution and ecological traits for 7657 (~75%) bird species based on geographical range polygons, and then used Bayesian phylogenetic analyses to test whether niche evolution was related to species richness and rates of diversification across genus and family‐level clades. 4.We found that the rate of climatic niche evolution has a positive linear relationship with both species richness and diversification rate at two different taxonomic levels (genus and family). Furthermore, this positive association between labile climatic niches and diversification was detected regardless of variation in clade latitude or key ecological traits. 5.Our findings suggest either that rapid adaptation to unoccupied areas of climatic niche space promotes avian diversification, or that diversification promotes adaptation. Either way, we propose that climatic niche evolution is a fundamental process regulating the link between climate and biodiversity at global scales, irrespective of the geographical and ecological context of speciation and extinction. This article is protected by copyright. All rights reserved.
      PubDate: 2016-04-11T09:15:40.980765-05:
      DOI: 10.1111/1365-2656.12530
  • Experimental parasite community ecology: intraspecific variation in a
           large tapeworm affects community assembly
    • Authors: D.P Benesh; M Kalbe
      Abstract: 1.Non‐random species associations occur in naturally‐sampled parasite communities. The processes resulting in predictable community structure (e.g. particular host behaviours, cross‐immunity, interspecific competition) could be affected by traits that vary within a parasite species, like growth or antigenicity. 2.We experimentally infected three‐spined sticklebacks with a large tapeworm (Schistocephalus solidus) that impacts the energy needs, foraging behaviour, and immune reactions of its host. The tapeworms came from two populations, characterized by high or low growth in sticklebacks. Our goal was to evaluate how this parasite, and variation in its growth, affects the acquisition of other parasites. 3.Fish infected with S. solidus were placed into cages in a lake to expose them to the natural parasite community. We also performed a lab experiment in which infected fish were exposed to a fixed dose of a common trematode parasite. 4.In the field experiment, infection with S. solidus affected the abundance of four parasite species, relative to controls. For two of the four species, changes occurred only in fish harbouring the high‐growth S. solidus; one species increased in abundance and the other decreased. These changes did not appear to be directly linked to S. solidus growth though. The parasite exhibiting elevated abundance was the same trematode used in the lab infection. In that experiment, we found a similar infection pattern, suggesting that S. solidus affects the physiological susceptibility of fish to this trematode. 5.Associations between S. solidus and other parasites occur and vary in direction. However, some of these associations were contingent on the S. solidus population, suggesting that intraspecific variability can affect the assembly of parasite communities. This article is protected by copyright. All rights reserved.
      PubDate: 2016-04-08T03:17:03.791584-05:
      DOI: 10.1111/1365-2656.12527
  • Phylogenetic Community Structure of North American Desert Bats: Influence
           of Environment at Multiple Spatial and Taxonomic Scales
    • Authors: Lorelei E. Patrick; Richard D. Stevens
      Abstract: 1.Numerous processes influence community structure. The relative importance of these processes are thought to vary with spatial, temporal, and taxonomic scale: density dependent interactions are thought to be most influential at small scales, at intermediate scales environmental conditions may be the most influential factor, and biogeographic processes are thought to be of greater importance at larger scales. Additionally, the stress‐dominance hypothesis suggests that communities experiencing harsher environmental conditions will be predominantly structured by habitat filtering whereas communities experiencing more favorable conditions will be structured predominantly by density dependent interactions such as competition. 2.The aim of this study was to investigate the influence of environmental factors on phylogenetic community structure (PCS) of North American desert bats at multiple spatial and taxonomic scales. We also examined if the stress‐dominance hypothesis is upheld in desert bats across an environmental gradient. 3.PCS metrics were calculated using species pools that differed in spatial (from all deserts to individual deserts) and taxonomic (all bat taxa, a single family, and a single genus) scale. We calculated mean temperature, precipitation, and seasonality for each site to determine if environmental gradients were related to degree of community structure. 4.At the largest spatial and taxonomic scales, communities were significantly phylogenetically clustered while degree of clustering decreased at the smallest spatial and taxonomic scales. Climatic data, particularly mean temperature and temperature seasonality, were important predictors of PCS at larger scales and under harsher conditions, but at smaller scales and in less stressful conditions there was a weaker relationship between PCS and climate. 5.This suggests that North American deserts, while harsh, are not uniform in the challenges they present to the faunas residing in them. Overall, the relationship between PCS and climatic data at large spatial and taxonomic scales, and in harsher conditions, suggests the influence of habitat filtering has been important in North American desert bat community assembly and that other processes have been important at smaller scales. This article is protected by copyright. All rights reserved.
      PubDate: 2016-04-08T03:16:33.085744-05:
      DOI: 10.1111/1365-2656.12529
  • Foraging modality and plasticity in foraging traits determine the strength
           of competitive interactions among carnivorous plants, spiders, and toads
    • Authors: David E. Jennings; James J. Krupa, Jason R. Rohr
      Abstract: 1.Foraging modalities (e.g., passive, sit‐and‐wait, active) and traits are plastic in some species, but the extent to which this plasticity affects interspecific competition remains unclear. 2.Using a long‐term laboratory mesocosm experiment, we quantified competition strength and the plasticity of foraging traits in a guild of generalist predators of arthropods with a range of foraging modalities. 3.Each mesocosm contained eight passively foraging pink sundews, and we employed an experimental design where treatments were the presence or absence of a sit‐and‐wait foraging spider and actively foraging toad crossed with five levels of prey abundance. We hypothesized that actively foraging toads would outcompete the other species at low prey abundance, but that spiders and sundews would exhibit plasticity in foraging traits to compensate for strong competition when prey were limited. 4.Results generally supported our hypotheses. Toads had a greater effect on sundews at low prey abundances, and toad presence caused spiders to locate webs higher above the ground. Additionally, the closer large spider webs were to the ground, the greater the trichome densities produced by sundews. Also, spider webs were larger with than without toads and as sundew numbers increased, and these effects were more prominent as resources became limited. Finally, spiders negatively affected toad growth only at low prey abundance. 5.These findings highlight the long‐term importance of foraging modality and plasticity of foraging traits in determining the strength of competition within and across taxonomic kingdoms. Future research should assess whether plasticity in foraging traits helps to maintain coexistence within this guild and whether foraging modality can be used as a trait to reliably predict the strength of competitive interactions. This article is protected by copyright. All rights reserved.
      PubDate: 2016-04-08T03:01:34.125136-05:
      DOI: 10.1111/1365-2656.12526
  • The challenges of the first migration: movement and behavior of juvenile
           versus adult white storks with insights regarding juvenile mortality
    • Authors: Shay Rotics; Michael Kaatz, Yehezkel S Resheff, Sondra Feldman Turjeman, Damaris Zurell, Nir Sapir, Ute Eggers, Andrea Flack, Wolfgang Fiedler, Florian Jeltsch, Martin Wikelski, Ran Nathan
      Abstract: 1.Migration conveys an immense challenge especially for juvenile birds coping with enduring and risky journeys shortly after fledging. Accordingly, juveniles exhibit considerably lower survival rates compared to adults, particularly during migration. Also, juvenile white storks (Ciconia ciconia), which are known to rely on adults during their first fall migration, presumably for navigational purposes, display much lower annual survival than adults. 2.Using detailed GPS and body acceleration data, we examined the patterns and potential causes of age‐related differences in fall migration properties of white storks by comparing first‐year juveniles and adults. We compared juvenile and adult parameters of movement, behavior and energy expenditure (estimated from overall dynamic body acceleration, ODBA) and placed this in the context of the juveniles’ lower survival rate. 3.Juveniles used flapping flight versus soaring flight 23% more than adults and were estimated to expend 14% more energy during flight. Juveniles did not compensate for increased flight costs by increased refueling or resting during migration. When juveniles and adults migrated together in the same flock, the juvenile flew mostly behind the adult and was left behind when they separated. Juveniles showed greater improvement in flight efficiency throughout migration compared to adults which appears crucial because juveniles exhibiting higher flight costs suffered increased mortality. 4.Our findings demonstrate the conflict between the juveniles’ inferior flight skills and their urge to keep up with mixed adult‐juvenile flocks. We suggest that increased flight costs are an important proximate cause of juvenile mortality in white storks and likely in other soaring migrants, and that natural selection is operating on juvenile variation in flight efficiency. This article is protected by copyright. All rights reserved.
      PubDate: 2016-04-05T01:26:38.429253-05:
      DOI: 10.1111/1365-2656.12525
  • Fight‐flight or freeze‐hide' Personality and metabolic
           phenotype mediate physiological defence responses in flatfish
    • Authors: E.J. Rupia; S.A. Binning, D.G. Roche, W. Lu
      Abstract: 1.Survival depends on appropriate behavioural and physiological responses to danger. In addition to active “fight‐flight” defence responses, a passive “freeze‐hide” response is adaptive in some contexts. However, the physiological mechanisms determining which individuals choose a given defence response remain poorly understood. 2.We examined the relationships among personality, metabolic performance and physiological stress responses across an environmental gradient in the olive flounder, Paralichthys olivaceus. 3.We employed four behavioural assays to document the existence of two distinct behavioural types (“bold” and “shy”) in this species. We found consistent metabolic differences between individuals of a given behavioural type across an environmental gradient: shy individuals had overall lower aerobic scope, maximum metabolic rate and standard metabolic rate than bold individuals in both high (25ppt) and low (3ppt) salinity. 4.These behavioural and metabolic differences translated into divergent physiological responses during acute stress: shy individuals adopted a passive “freeze‐hide” response by reducing their oxygen consumption rates (akin to shallow breathing) whereas bold individuals adopted an active “fight‐flight” response by increasing their rates of respiration. These distinct defence strategies were repeatable within individuals between salinity treatments. 5.Although it has been suggested theoretically, this is the first empirical evidence that the metabolic response to stressful situations differs between bold and shy individuals. Our results emphasize the importance of incorporating physiological measures to understand the mechanisms driving persistent inter‐individual differences in animals. This article is protected by copyright. All rights reserved.
      PubDate: 2016-04-05T01:26:01.434406-05:
      DOI: 10.1111/1365-2656.12524
  • Host and parasite thermal acclimation responses depend on the stage of
    • Authors: Karie A. Altman; Sara H. Paull, Pieter T. J. Johnson, Michelle N. Golembieski, Jeffrey P. Stephens, Bryan E. LaFonte, Thomas R. Raffel
      Abstract: Global climate change is expected to alter patterns of temperature variability, which could influence species interactions including parasitism. Species interactions can be difficult to predict in variable‐temperature environments because of thermal acclimation responses, i.e. physiological changes that allow organisms to adjust to a new temperature following a temperature shift. The goal of this study was to determine how thermal acclimation influences host resistance to infection and to test for parasite acclimation responses, which might differ from host responses in important ways. We tested predictions of three, non‐mutually exclusive hypotheses regarding thermal acclimation effects on infection of green frog tadpoles (Lithobates clamitans) by the trematode parasite Ribeiroia ondatrae with fully replicated controlled‐temperature experiments. Trematodes or tadpoles were independently acclimated to a range of ‘acclimation temperatures’ prior to shifting them to new ‘performance temperatures’ for experimental infections. Trematodes that were acclimated to intermediate temperatures (19–22 °C) had greater encystment success across temperatures than either cold‐ or warm‐acclimated trematodes. However, host acclimation responses varied depending on the stage of infection (encystment vs. clearance): warm‐ (22–28 °C) and cold‐acclimated (13–19 °C) tadpoles had fewer parasites encyst at warm and cold performance temperatures, respectively, whereas intermediate‐acclimated tadpoles (19–25 °C) cleared the greatest proportion of parasites in the week following exposure. These results suggest that tadpoles use different immune mechanisms to resist different stages of trematode infection, and that each set of mechanisms has unique responses to temperature variability. Our results highlight the importance of considering thermal responses of both parasites and hosts when predicting disease patterns in variable‐temperature environments. Temperature variability can have complex effects on parasitism, particularly if hosts and parasites acclimate to new temperatures. The authors used replicated temperature experiments to demonstrate nonlinear thermal acclimation responses in the trematode parasite Ribeiroia ondatrae and its tadpole host Lithobates clamitans. They tracked parasite encystment and clearance using fluorescent dye.
      PubDate: 2016-04-04T03:52:49.213894-05:
      DOI: 10.1111/1365-2656.12510
  • The contribution of developmental experience vs. condition to life
           history, trait variation, and individual differences
    • Abstract: 1.Developmental experience, for example food abundance during juvenile stages, is known to affect life history and behaviour. However, the life history and behavioural consequences of developmental experience have rarely been studied in concert. As a result it is still unclear whether developmental experience affects behaviour through changes in life history, or independently of it. 2.The effect of developmental experience on life history and behaviour may also be masked or affected by individual condition during adulthood. Thus, it is critical to tease apart the effects of developmental experience and current individual condition on life history and behaviour. 3.In this study we manipulated food abundance during development in the western black widow spider, Latrodectus hesperus, by rearing spiders on either a restricted or ad lib diet. We separated developmental from condition dependent effects by assaying adult foraging behaviour (tendency to attack prey and to stay on out of the refuge following an attack) and web structure multiple times under different levels of satiation following different developmental treatments. 4.Spiders reared under food restriction matured slower and at a smaller size than spiders reared in ad lib conditions. Spiders reared on a restricted diet were more aggressive towards prey and built webs structured for prey capture while spiders reared on an ad lib diet were less aggressive and build safer webs. Developmental treatment affected which traits were plastic as adults: restricted spiders built safer webs when their adult condition increased, while ad‐lib spiders reduced their aggression when their adult condition increased. The amount of individual variation in behaviour and web structure varied with developmental treatment. Spiders reared on a restricted diet exhibited consistent variation in all aspects of foraging behaviour and web structure, while spiders reared on an ad lib diet exhibited consistent individual variation in aggression and web weight only. 5.Developmental experience affected the average life history, behaviour, and web structure of spiders, but also shaped the amount of phenotypic variation observed among individuals. Surprisingly, developmental experience also determined the particular way in which individuals plastically adjusted their behaviour and web structure to changes in adult condition. This article is protected by copyright. All rights reserved.
      PubDate: 2016-03-24T09:20:47.95106-05:0
      DOI: 10.1111/1365-2656.12512
  • Does primary productivity modulate the indirect effects of large
           herbivores' A global meta‐analysis
    • Authors: Joshua H. Daskin; Robert M. Pringle
      Abstract: 1.Indirect effects of large mammalian herbivores (LMH), while much less studied than those of apex predators, are increasingly recognized to exert powerful influences on communities and ecosystems. The strength of these effects is spatiotemporally variable, and several sets of authors have suggested that they are governed in part by primary productivity. However, prior theoretical and field studies have generated conflicting results and predictions, underscoring the need for a synthetic global analysis. 2.We conducted a meta‐analysis of the direction and magnitude of large mammalian herbivore‐initiated indirect interactions using 67 published studies comprising 456 individual responses. We georeferenced 41 of these studies (comprising 253 responses from 33 locations on 5 continents) to a satellite‐derived map of primary productivity. Because predator assemblages might also influence the impact of large herbivores, we conducted a similar analysis using a global map of large‐carnivore species richness. 3.In general, LMH reduced the abundance of other consumer species and also tended to reduce consumer richness, although the latter effect was only marginally significant. 4.There was a pronounced reduction in the strength of negative (i.e., suppressive, due e.g. to competition) indirect effects of LMH on consumer abundance in more productive ecosystems. In contrast, positive (facilitative) indirect effects were not significantly correlated with productivity, likely because these comprised a more heterogeneous array of mechanisms. We found no effect of carnivore species richness on herbivore‐initiated indirect effect strength. 5.Our findings help to resolve the fundamental problem of ecological contingency as it pertains to the strength of an under‐studied class of multi‐trophic interactions. Moreover, these results will aid in predicting the indirect effects of anthropogenic wildlife declines and irruptions, and how these effects might be mediated by climatically driven shifts in resource availability. To the extent that intact ungulate guilds help to suppress populations of small animals that act as agricultural pests and disease reservoirs, the negative impacts of large‐mammal declines on human well‐being may be relatively stronger in low‐productivity areas. This article is protected by copyright. All rights reserved.
      PubDate: 2016-03-23T09:10:41.70089-05:0
      DOI: 10.1111/1365-2656.12522
  • Mimicry refinement: Phenotypic variations tracking the local optimum
    • Abstract: 1.Müllerian mimicry between chemically defended preys is a textbook example of natural selection favouring phenotypic convergence onto a shared warning signal. Studies of mimicry have concentrated on deciphering the ecological and genetic underpinnings of dramatic switches in mimicry association, producing a well‐known mosaic distribution of mimicry patterns across geography. However, little is known about the accuracy of resemblance between natural co‐mimics when the local phenotypic optimum varies. 2.In this study, using analyses of wing shape, pattern and hue, we quantify multimodal phenotypic similarity between butterfly co‐mimics sharing the so‐called postman pattern in different localities with varying species composition. 3.We show that subtle but consistent variation between populations of the localised species, Heliconius timareta thelxinoe, enhance resemblance to the abundant co‐mimics which drive the mimicry in each locality. 4.Those results suggest that rarer co‐mimics track the changes in the phenotypic optimum caused by gradual changes in the composition of the mimicry community, providing insights into the process by which intra‐specific diversity of mimetic pattern may arise. Furthermore, our results suggest a multimodal evolution of similarity, with coordinated convergence in different features of the phenotype such as wing outline, pattern and hue. 5.Finally, multilocus genotyping allows estimating local hybridization rates between H. timareta and co‐mimic H. melpomene in different populations, raising the hypothesis that mimicry refinement between closely‐related co‐mimics may be enhanced by adaptive introgression at loci modifying the accuracy of resemblance. This article is protected by copyright. All rights reserved.
      PubDate: 2016-03-22T08:15:49.420547-05:
      DOI: 10.1111/1365-2656.12521
  • Antagonistic interactions between an invasive alien and a native
           coccinellid species may promote coexistence
    • Authors: William T. Hentley; Adam J. Vanbergen, Andrew P. Beckerman, Melanie N. Brien, Rosemary S. Hails, Hefin T. Jones, Scott N. Johnson
      Abstract: Despite the capacity of invasive alien species to alter ecosystems, the mechanisms underlying their impact remain only partly understood. Invasive alien predators, for example, can significantly disrupt recipient communities by consuming prey species or acting as an intraguild predator (IGP). Behavioural interactions are key components of interspecific competition between predators, yet these are often overlooked invasion processes. Here, we show how behavioural, non‐lethal IGP interactions might facilitate the establishment success of an invading alien species. 3) We experimentally assessed changes in feeding behaviour (prey preference and consumption rate) of native UK coccinellid species (Adalia bipunctata and Coccinella septempunctata), whose populations are, respectively, declining and stable, when exposed to the invasive intraguild predator, Harmonia axyridis. Using a population dynamics model parameterised with these experimental data, we predicted how intraguild predation, accommodating interspecific behavioural interactions, might impact the abundance of the native and invasive alien species over time. 4) When competing for the same aphid resource, the feeding rate of A. bipunctata significantly increased compared to the feeding in isolation, while the feeding rate of H. axyridis significantly decreased. This suggests that despite significant declines in the UK, A. bipunctata is a superior competitor to the intraguild predator H. axyridis. In contrast, the behaviour of non‐declining C. septempunctata was unaltered by the presence of H. axyridis. 5) Our experimental data show the differential behavioural plasticity of competing native and invasive alien predators, but do not explain A. bipunctata declines observed in the UK. Using behavioural plasticity as a parameter in a population dynamic model for A. bipunctata and H. axyridis, coexistence is predicted between the native and invasive alien following an initial period of decline in the native species. We demonstrate how empirical and theoretical techniques can be combined to understand better the processes and consequences of alien species invasions for native biodiversity. This article is protected by copyright. All rights reserved.
      PubDate: 2016-03-21T06:08:28.808892-05:
      DOI: 10.1111/1365-2656.12519
  • Evidence of the phenotypic expression of a lethal recessive allele under
           inbreeding in a wild population of conservation concern
    • Authors: Amanda E. Trask; Eric M. Bignal, Davy I. McCracken, Pat Monaghan, Stuart B. Piertney, Jane M. Reid
      Abstract: Deleterious recessive alleles that are masked in outbred populations are predicted to be expressed in small, inbred populations, reducing both individual fitness and population viability. However, there are few definitive examples of phenotypic expression of lethal recessive alleles under inbreeding conditions in wild populations. Studies that demonstrate the action of such alleles, and infer their distribution and dynamics, are required to understand their potential impact on population viability and inform management responses. The Scottish population of red‐billed choughs (Pyrrhocorax pyrrhocorax), which currently totals
      PubDate: 2016-03-21T01:10:49.27152-05:0
      DOI: 10.1111/1365-2656.12503
  • Food availability and predation risk, rather than intrinsic attributes are
           the main factors shaping the reproductive decisions of a long‐lived
    • Authors: Sarah R. Hoy; Alexandre Millon, Steve J. Petty, D. Philip Whitfield, Xavier Lambin
      Abstract: Deciphering the causes of variation in reproductive success is a fundamental issue in ecology, as the number of offspring produced is an important driver of individual fitness and population dynamics. Little is known however, about how different factors interact to drive variation in reproduction, such as whether an individual's response to extrinsic conditions (e.g. food availability or predation) varies according to its intrinsic attributes (e.g. age, previous allocation of resources towards reproduction). We used 29 years of reproductive data from marked female tawny owls and natural variation in food availability (field vole) and predator abundance (northern goshawk) to quantify the extent to which extrinsic and intrinsic factors interact to influence owl reproductive traits (breeding propensity, clutch size and nest abandonment). Extrinsic and intrinsic factors appeared to interact to affect breeding propensity (which accounted for 83% of the variation in owl reproductive success). Breeding propensity increased with vole density, although increasing goshawk abundance reduced the strength of this relationship. Owls became slightly more likely to breed as they aged, although this was only apparent for individuals who had fledged chicks the year before. Owls laid larger clutches when food was more abundant. When owls were breeding in territories less exposed to goshawk predation, 99.5% of all breeding attempts reached the fledging stage. In contrast, the probability of breeding attempts reaching the fledging stage in territories more exposed to goshawk predation depended on the amount of resources an owl had already allocated towards reproduction (averaging 87.7% for owls with clutches of 1‐2 eggs compared to 97.5% for owls with clutches of 4‐6 eggs). Overall, our results suggested that changes in extrinsic conditions (predominantly food availability, but also predator abundance) had the greatest influence on owl reproduction. In response to deteriorating extrinsic conditions (fewer voles and more goshawks) owls appeared to breed more frequently, but allocated fewer resources per breeding attempt. However, intrinsic attributes also appeared to have a relatively small influence on how an individual responded to variation in extrinsic conditions, which indicates that reproductive decisions were shaped by a complex series of extrinsic and intrinsic trade‐offs. This article is protected by copyright. All rights reserved.
      PubDate: 2016-03-15T06:06:25.967881-05:
      DOI: 10.1111/1365-2656.12517
  • Family morph matters: factors determining survival and recruitment in a
           long‐lived polymorphic raptor
    • Authors: P. Sumasgutner; G. J. Tate, A. Koeslag, A. Amar
      Abstract: From an evolutionary perspective recruitment into the breeding population represents one of the most important life history stages and ultimately determines the effective population size. In order to contribute to the next generation, offspring must survive to sexual maturity, secure a territory and find a mate. In this study we explore factors influencing both offspring survival and their subsequent recruitment into the local breeding population in a long‐lived urban raptor, the black sparrowhawk (Accipiter melanoleucus). Adult black sparrowhawks show discrete colour polymorphism (dark and light morphs) and in South Africa morphs are distributed clinally with the highest proportion of dark morphs (c.75%) present in our study population on the Cape Peninsula. Parental morph was associated with both survival and recruitment. For survival, parental morph combination was important – with young produced by pairs of contrasting morphs having higher survival rates than young fledged from like‐pairs. The association between recruitment and morph was more complex; with an interaction between male morph and breeding time, whereby recruitment of offspring from dark morph fathers was more likely when fledging earlier in the season. The opposite relationship was found for light morph fathers, with their offspring more likely to be recruited if fledged later in the season. This interaction may be due to differential morph‐specific hunting success of fathers (males contribute most food provisioning), linked to background matching and crypsis in different weather conditions. Dark morph males may hunt more successfully in rainier and cloudier conditions which occur more frequently earlier in the breeding season and light morph males may be more successful later on, when weather conditions become increasingly brighter and drier. Our results reveal a complex situation whereby the family morph combination influences survival, and the father morph specifically recruitment, revealing morph specific benefits dependent on the timing of breeding. These empirical data are amongst the first to support the idea that differential fitness consequence of morph combination may explain balanced polymorphism in a vertebrate population. This article is protected by copyright. All rights reserved.
      PubDate: 2016-03-15T05:40:49.179961-05:
      DOI: 10.1111/1365-2656.12518
  • A test of the effects of timing of a pulsed resource subsidy on stream
    • Abstract: 1.Spatial resource subsidies can alter bottom‐up and top‐down forces of community regulation across ecosystem boundaries. Most subsidies are temporally variable, and recent theory has suggested that consumer‐resource dynamics can be stabilized if the peak timing of a subsidy is desynchronized with that of prey productivity in the recipient ecosystem. However, magnitude of consumer responses per se could depend on the subsidy timing, which may be a critical component for community dynamics and ecosystem processes. 2.The aim of this study was to test (1) whether a recipient consumer (cutthroat trout) responds differently to a resource subsidy occurring early in its growing season than to a subsidy occurring late in the season, and, if this is the case, (2) whether the timing‐dependent consumer response has cascading effects on communities and ecosystem functions in streams. 3.To test those hypotheses, we conducted a large‐scale field experiment, in which we directly manipulated the timing of augmentation of the terrestrial invertebrates that enter stream (i.e., peak timing of June‐August vs. August‐October), keeping constant the total amounts of the invertebrates entered. 4.We found large increases in the individual growth rate and population biomass of the cutthroat trout, in response to the early resource pulse, but not to the late pulse. This timing‐dependent consumer response cascaded down to reduce benthic invertebrates and leaf break‐down rate, and increased water nutrient concentrations. Furthermore, the early resource pulse resulted in higher maturity rate of the cutthroat trout in the following spring, demonstrating the importance of the subsidy timing on long‐term community dynamics via the consumer's numerical response. 5.Our results emphasize the need to acknowledge timing‐dependent consumer responses in understanding the effects of subsidies on communities and ecosystem processes. Elucidating the mechanisms by which consumers effectively exploit pulsed subsidies is an important avenue to better understand community dynamics in spatially coupled ecosystems. This article is protected by copyright. All rights reserved.
      PubDate: 2016-03-12T10:25:42.761997-05:
      DOI: 10.1111/1365-2656.12516
  • Negative relationships between population density and metabolic rates are
           not general
    • Abstract: 1.Population density has recently been suggested to be an important factor influencing metabolic rates, and to represent an important ‘third axis’ explaining variation beyond that explained by body mass and temperature. In situations where population density influences food consumption, the immediate effect on metabolism acting through specific dynamic action (SDA), and downregulation due to fasting over longer periods, is well understood. However, according to a recent review, previous studies suggest a more general effect of population density per se, even in the absence of such effects. It has been hypothesised that this results from animals performing anticipatory responses (i.e. reduced activity) to expected declines in food availability. 2.Here we test the generality of this finding by measuring density effects on metabolic rates in 10 clones from two different species of the zooplankton Daphnia (Daphnia pulex Leydig and D. magna Straus). Using fluorescence‐based respirometry we obtain high‐precision measures of metabolism. 3.We also identify additional studies on this topic that were not included in the previous review, compare the results, and evaluate the potential for measurement bias in all previous studies. 4.We demonstrate significant variation in mass‐specific metabolism among clones within both species. However, we find no evidence for a negative relationship between population density and mass‐specific metabolism. The previously reported pattern also disappeared when we extended the set of studies analysed. 5.We discuss potential reasons for the discrepancy among studies, including two main sources of potential bias (microbial respiration and declining oxygen consumption due to reduced oxygen availability). Only one of the previous studies gives sufficient information to conclude absence of such biases, and consistent with our results no effect of density on metabolism was found. We conclude that population density per se does not have a general effect on mass‐specific metabolic rate. This article is protected by copyright. All rights reserved.
      PubDate: 2016-03-11T09:34:10.778801-05:
      DOI: 10.1111/1365-2656.12515
  • Colonization history and clonal richness of asexual Daphnia in periglacial
           habitats of contrasting age in West Greenland
    • Authors: Tsegazeabe H Haileselasie; Joachim Mergeay, Lawrence J . Weider, Erik Jeppesen, Luc De Meester
      Abstract: 1.Due to climate change, Arctic ice sheets are retreating. This leads to the formation of numerous new periglacial ponds and lakes, which are being colonized by planktonic organisms such as the water flea Daphnia. This system provides unique opportunities to test genotype colonization dynamics and the genetic assemblage of populations. Here, we studied clonal richness of the Daphnia pulex species complex in novel periglacial habitats created by glacial retreat in the Jakobshavn Isbræ area of western Greenland. 2.Along a 10 km transect, we surveyed 73 periglacial habitats out of which 61 were colonized by Daphnia pulex. Hence for our analysis we used 21 ponds and 40 lakes in two clusters of habitats differing in age (estimated 150 years). We tested the expectation that genetic diversity would be low in recently‐formed (i.e., young), small habitats, but would increase with increasing age and size. 3.We identified a total of 42 genetically‐distinct clones belonging to two obligately asexual species of the D. pulex species complex: D. middendorffiana and the much more abundant D. pulicaria. While regional clonal richness was high, most clones were rare: 16 clones were restricted to a single habitat and the five most widespread clones accounted for 68% of all individuals sampled. On average 3.2 clones (range: 1‐12) coexisted in a given pond or lake. There was no relationship between clonal richness and habitat size when we controlled for habitat age. Whereas clonal richness was statistically higher in the cluster of older habitats when compared with the cluster of younger ponds and lakes, most young habitats were colonized by multiple genotypes. 4.Our data suggest that newly‐formed (periglacial) ponds and lakes are within decades colonized by multiple genotypes via multiple colonization events, even in the smallest of our study systems (4 m2). This article is protected by copyright. All rights reserved.
      PubDate: 2016-03-08T03:15:51.251358-05:
      DOI: 10.1111/1365-2656.12513
  • Beyond neutral and forbidden links: morphological matches and the assembly
           of mutualistic hawkmoth‐plant networks
    • Abstract: 1.A major challenge in evolutionary ecology is to understand how coevolutionary processes shape patterns of interactions between species at community level. Pollination of flowers with long corolla tubes by long‐tongued hawkmoths has been invoked as a showcase model of coevolution. Recently, optimal foraging models have predicted that there might be a close association between mouthparts length and the corolla depth of the visited flowers, thus favouring trait convergence and specialisation at community level. 2.Here, we assessed whether hawkmoths more frequently pollinate plants with floral tube lengths similar to their proboscis lengths (morphological match hypothesis) against abundance‐based processes (neutral hypothesis) and ecological trait mismatches constraints (forbidden links hypothesis), in structuring hawkmoth‐plant mutualistic networks from five communities in four biogeographical regions of South America. 3.We found convergence in morphological traits across the five communities and that the distribution of morphological differences between hawkmoths and plants is consistent with expectations under the morphological match hypothesis in three of the five communities. In the two remaining communities, which are ecotones between two distinct biogeographic areas, interactions are better predicted by the neutral hypothesis. 4.Our findings are consistent with the idea that diffuse coevolution drives the evolution of extremely long proboscises and flower tubes, and highlight the importance of morphological traits, beyond the forbidden links hypothesis, in structuring interactions between mutualistic partners, revealing that the role of niche‐based processes can be much more complex than previously known. This article is protected by copyright. All rights reserved.
      PubDate: 2016-03-02T02:45:04.321843-05:
      DOI: 10.1111/1365-2656.12509
  • Larval traits carry over to affect post‐settlement behaviour in a
           common coral reef fish
    • Authors: Andrea L. Dingeldein; J Wilson White
      Abstract: 1.Most reef fishes begin life as planktonic larvae before settling to the reef, metamorphosing, and entering the benthic adult population. Different selective forces determine survival in the planktonic and benthic life stages, but traits established in the larval stage may carry over to affect post‐settlement performance. We tested the hypothesis that larval traits affect two key post‐settlement fish behaviours: social group‐joining and foraging. 2.Certain larval traits of reef fishes are permanently recorded in the rings in their otoliths. In the bluehead wrasse (Thalassoma bifasciatum), prior work has shown that key larval traits recorded in otoliths (growth rate, energetic condition at settlement) carry‐over to affect post‐settlement survival on the reef, with higher‐larval‐condition fish experiencing less post‐settlement mortality. We hypothesized that this selective mortality is mediated by carry‐over effects on post‐settlement anti‐predator behaviours. We predicted that better‐condition fish would forage less and be more likely to join groups, both behaviours that would reduce predation risk. 3.We collected 550 recently settled bluehead wrasse (Thalassoma bifasciatum) from three reef sites off St. Croix (USVI), and performed two analyses. First, we compared each settler's larval traits to the size of its social group to determine whether larval traits influenced group‐joining behaviour. Second, we observed foraging behaviour in a subset of focal grouped and solitary fish (n = 14) for 1‐4 days post‐settlement. We then collected the fish and tested whether larval traits influenced the proportion of time spent foraging. 4.Body length at settlement, but not condition, affected group‐joining behaviour; smaller fish were more likely to remain solitary or in smaller groups. However, both greater length and better condition were associated with greater proportions of time spent foraging over four consecutive days post‐settlement. 5.Larval traits carry‐over to affect post‐settlement behavior, though not as we expected: higher‐quality larvae join groups more frequently (safer) but then forage more. Foraging is risky but may allow faster post‐settlement growth, reducing mortality risk in the long run. This shows that behaviour likely serves as a mechanistic link connecting larval traits to post‐settlement selective mortality. This article is protected by copyright. All rights reserved.
      PubDate: 2016-02-23T13:32:11.585206-05:
      DOI: 10.1111/1365-2656.12506
  • Endemicity of chytridiomycosis features pathogen over‐dispersion
    • Authors: Laura F. Grogan; Andrea. D. Phillott, Benjamin C. Scheele, Lee Berger, Scott D. Cashins, Sara C. Bell, Robert Puschendorf, Lee F. Skerratt
      Abstract: 1.Pathogens can be critical drivers of the abundance and distribution of wild animal populations. The presence of an over‐dispersed pathogen load distribution between hosts (where few hosts harbor heavy parasite burdens and light infections are common) can have an important stabilizing effect on host‐pathogen dynamics where infection intensity determines pathogenicity. This may potentially lead to endemicity of an introduced pathogen rather than extirpation of the host and/or pathogen. 2.Over‐dispersed pathogen load distributions have rarely been considered in wild animal populations as an important component of the infection dynamics of microparasites such as bacteria, viruses, protozoa and fungi. 3.Here we examined the abundance, distribution and transmission of the model fungal pathogen Batrachochytrium dendrobatidis (Bd, cause of amphibian chytridiomycosis) between wild‐caught Litoria rheocola (common mist frogs) to investigate the effects of an over‐dispersed pathogen load distribution on the host population in the wild. We quantified host survival, infection incidence and recovery probabilities relative to infectious burden, and compared the results of models where pathogen over‐dispersion either was or was not considered an important feature of host‐pathogen dynamics. 4.We found the distribution of Bd load between hosts to be highly over‐dispersed. We found that host survival was related to infection burden, and that accounting for pathogen over‐dispersion allowed us to better understand infection dynamics and their implications for disease control. In addition, we found that the pattern of host infections and recoveries varied markedly with season whereby (i) infections established more in winter, consistent with temperature dependent effects on fungal growth, and (ii) recoveries (loss of infection) occurred frequently in the field throughout the year but were less likely in winter. 5.Our results suggest that pathogen over‐dispersion is an important feature of endemic chytridiomycosis, and that intensity of infection determines disease impact. These findings have important implications for our understanding of chytridiomycosis dynamics and the application of management strategies for disease mitigation. We recommend quantifying individual infectious burdens rather than infection state where possible in microparasitic diseases. This article is protected by copyright. All rights reserved.
      PubDate: 2016-02-04T21:14:08.663191-05:
      DOI: 10.1111/1365-2656.12500
  • Integrating the pace‐of‐life syndrome across species, sexes
           and individuals: covariation of life history and personality under
           pesticide exposure
    • Abstract: 1.The pace‐of‐life syndrome (POLS) hypothesis integrates covariation of life‐history traits along a fast‐slow continuum and covariation of behavioural traits along a proactive‐reactive personality continuum. Few studies have investigated these predicted life‐history/personality associations among species and between sexes. Furthermore, whether and how contaminants interfere with POLS patterns remains unexplored. 2.We tested for covariation patterns in life history and in behaviour, and for life‐history/personality covariation among species, among individuals within species and between sexes. Moreover, we investigated whether pesticide exposure affects covariation between life history and behaviour and whether species and sexes with a faster POLS strategy have a higher sensitivity to pesticides. 3.We reared larvae of four species of Ischnura damselflies in a common garden experiment with an insecticide treatment (chlorpyrifos absent/present) in the final instar. We measured four life‐history traits (larval growth rate during the pesticide treatment and development time; adult mass and lifespan) and two behavioural traits (larval feeding activity and boldness, each before and after the pesticide treatment). 4.At the individual level, life‐history traits and behavioural traits aligned along a fast‐slow and a proactive‐reactive continuum, respectively. Species‐specific differences in life history, with fast‐lived species having a faster larval growth and development, a lower mass at emergence and a shorter lifespan, suggested that time constraints in the larval stage were predictably driving life‐history evolution both in the larval stage and across metamorphosis in the adult stage. Across species, females were consistently more slow‐lived than males, reflecting that a large body size and a long lifespan are generally more important for females. In contrast to the POLS hypothesis, there was only little evidence for the expected positive coupling between life‐history pace and proactivity. Pesticide exposure decreased larval growth rate and affected life‐history/personality covariation in the most fast‐lived species. 5.Our study supports the existence of life‐history and behavioural continua with limited support for life‐history/personality covariation. Variation in digestive physiology may explain this decoupling of life history and behaviour and provide valuable mechanistic insights to understand and predict the occurrence of life‐history/personality covariation patterns. This article is protected by copyright. All rights reserved.
      PubDate: 2016-02-04T12:51:17.123915-05:
      DOI: 10.1111/1365-2656.12499
  • The rules for symbiont community assembly change along a
           mutualism‐parasitism continuum
    • Authors: James Skelton; Sam Doak, Meredith Leonard, Robert P. Creed, Bryan L. Brown
      Abstract: 1.Symbiont community assembly is driven by host‐symbiont and symbiont‐symbiont interactions.The effects that symbionts exert on their hosts are often context‐dependent and existing theoretical frameworks of symbiont community assembly do not consider the implications of variable outcomes to assembly processes. 2.We hypothesized that symbiont‐symbiont interactions become increasingly important along a parasitism/mutualism continuum because; a) negative outcomes favor host resistance which in turn reduces symbiont colonization and subsequently reduce symbiont‐symbiont interactions, whereas b) positive host outcomes favor tolerance and consequently higher symbiont colonization rates, leading to stronger interactions among symbionts. We found support for this hypothesis in the cleaning symbiosis between crayfish and ectosymbiotic branchiobdellidan worms. 3.The symbiosis between crayfish and their worms can shift from parasitism/commensalism to mutualism as crayfish age. Here, field surveys identified changes in worm density, diversity, and composition that were concomitant to changing symbiosis outcomes. We conducted several laboratory experiments and behavioral assays to relate patterns from the field to their likely causal processes. 4.Young crayfish typically hosted only two relatively small worm species. Older crayfish hosted two additional larger species. In laboratory experiments, young crayfish exhibited a directed grooming response to all worm species, but were unable to remove small species. Conversely, adult crayfish did not exhibit grooming responses to any worm species. Relaxed grooming allowed the colonization of large worm species and initiated symbiont‐symbiont intraguild predation that reduced the abundance and altered the behavior of small worm species. Thus, the dominant processes of symbiont community assembly shifted from host resistance to symbiont‐symbiont interactions through host ontogeny and a concomitant transition towards mutualism. 5.This work shows that host resistance can have a prevailing influence over symbiont community assembly when symbiosis is disadvantageous to the host. However, when symbiosis is advantageous and resistance is relaxed, symbiont colonization rate and consequently abundance and diversity increases, and interactions among symbionts become increasingly important to symbiont community assembly. This article is protected by copyright. All rights reserved.
      PubDate: 2016-02-01T01:51:42.019059-05:
      DOI: 10.1111/1365-2656.12498
  • Staying out of the heat: how habitat use is determined by local
    • Authors: Martin J. Genner
      Pages: 611 - 613
      Abstract: Atlantic cod (Gadus morhua) and the Tvedestrand fjord on the Norwegian Skagerrak coast studied by Freitas et al. (). Photographs by Øystein Paulsen (left), and Institute of Marine Research, Norway (right). In Focus: Freitas, C., Olsen, E. M., Knutsen, H., Albretsen, J. & Moland, E. (2016) Temperature‐associated habitat selection in a cold‐water marine fish. Journal of Animal Ecology, 85, 611–613. In the marine environment, species distributions are closely linked to temperature gradients, but how individual behaviour is affected by local temperatures is less well understood. Freitas et al. () tracked Atlantic cod within a Norwegian fjord using electronic acoustic tags. They showed that when surface waters were warm, cod occupied the cold deep non‐vegetated habitats. However, when surface waters cooled, fish moved into shallow seagrass and macroalgae beds that were previously out‐of‐bounds. The study provides a clear example of how thermal regimes determine habitat use over fine spatial and temporal scales, with potential implications for population dynamics under climate warming. Atlantic cod (Gadus morhua) and the Tvedestrand fjord on the Norwegian Skagerrak coast studied by Freitas et al. (2016). Photographs by Øystein Paulsen (top), and Institute of Marine Research, Norway (bottom).
      PubDate: 2016-04-25T11:03:09.760361-05:
      DOI: 10.1111/1365-2656.12502
  • Do animals exercise to keep fit'
    • Authors: Lewis G. Halsey
      First page: 614
      Abstract: We humans know we are not physically fit unless we do extra, voluntary exercise. Yet we have never asked whether the same is true for animals. If it is, then give that energy will be spent keeping fit this raises important issues about new energetic trade‐offs, which have never been considered.
      PubDate: 2016-01-21T02:00:03.242992-05:
      DOI: 10.1111/1365-2656.12488
  • Are generalist parasites being lost from their hosts'
    • Authors: Giovanni Strona; Simone Fattorini
      First page: 621
      Abstract: Co‐extinctions should be regarded as fundamental co‐evolutionary events promoting species turnover, prior than a consequence of human induced biodiversity loss. Focusing on current scenarios is key to biodiversity conservation, but predicting future trends could be harder and less fruitful than trying to get a better grasp on the past.
      PubDate: 2016-01-11T06:38:11.850337-05:
      DOI: 10.1111/1365-2656.12443
  • Response to Strona & Fattorini: are generalist parasites being lost
           from their hosts'
    • Authors: Maxwell J. Farrell; Patrick R. Stephens, T. Jonathan Davies
      First page: 624
      Abstract: We respond to criticism of our recent paper by examining assumptions about the structure of host‐parasite networks, and discuss the implications of host extinction on our perception of parasite specificity.
      PubDate: 2016-01-11T06:38:34.48114-05:0
      DOI: 10.1111/1365-2656.12470
  • Stable coexistence of ecologically identical species: conspecific
           aggregation via reproductive interference
    • Authors: Lasse Ruokolainen; Ilkka Hanski
      First page: 638
      Abstract: 1.Stable coexistence of ecologically identical species is not possible according to the established ecological theory. Many coexistence mechanisms have been proposed, but they all involve some form of ecological differentiation among the competing species. 2.The aggregation model of coexistence would predict coexistence of identical species if there would be a mechanism that generates spatially aggregated distributions that are not completely correlated among the species. Our aim is to demonstrate that continued dispersal, triggered by reproductive interference between ecologically identical species is such a mechanism. This study has been motivated by species using ephemeral patchy resources, such as decomposing fruits, fungal sporophores, carrion, and dung. 3.We analyse an individual‐based model with sexual reproduction, in which the progeny develops in ephemeral resource patches and the new generation disperses to a new set of patches. We assume spatially restricted dispersal, that patches differ in detectability, and that unmated females continue dispersal. 4.In the model, reproductive interference (males spend some time searching for and/or attempting to mate with heterospecific females) reduces the mating rate of females, especially in the less common species, which leads to increased dispersal and reduces spatial correlation in species’ distributions. 5.For a wide range of parameter values, coexisting species show a systematic difference in their relative abundances due to two opposing forces: uncommon species have reduced growth rate (Allee effect), which decreases abundance, but an abundance difference between the species reduces interspecific spatial correlation, which in turn reduces interspecific competition and allows the rarer species to persist at low density. 6.Our results demonstrate a new mechanism for coexistence that is not based on ecological differentiation between species. This article is protected by copyright. All rights reserved.
      PubDate: 2016-01-18T21:23:21.728038-05:
      DOI: 10.1111/1365-2656.12490
  • The response of migratory populations to phenological change: a Migratory
           Flow Network modelling approach
    • Authors: Caz M. Taylor; Andrew J. Laughlin, Richard J. Hall
      First page: 648
      Abstract: 1.Declines in migratory species have been linked to anthropogenic climate change through phenological mismatch, which arises due to asynchronies between the timing of life‐history events (such as migration) and the phenology of available resources. Long‐distance migratory species may be particularly vulnerable to phenological change in their breeding ranges, since the timing of migration departure is based on environmental cues at distant non‐breeding sites. 2.Migrants may, however, be able to adjust migration speed en route to the breeding grounds and thus ability of migrants to update their timing of migration may depend critically on stopover frequency during migration; however, understanding how migratory strategy influences population dynamics is hindered by a lack of predictive models explicitly linking habitat quality to demography and movement patterns throughout the migratory cycle. 3.Here, we present a novel modelling framework, the Migratory Flow Network (MFN), in which the seasonally varying attractiveness of breeding, winter, and stopover regions drives the direction and timing of migration based on a simple general flux law. 4.We use the MFN to investigate how populations respond to shifts in breeding site phenology based on their frequency of stopover and ability to detect and adapt to these changes. 5.With perfect knowledge of advancing phenology, ‘jump’ migrants (low frequency stopover) require more adaptation for populations to recover than ‘hop’ and ‘skip’ (high or medium frequency stopover) migrants. If adaptation depends on proximity, hop and skip migrants’ populations can recover but jump migrants cannot adjust and decline severely. 6.These results highlight the importance of understanding migratory strategies and maintaining high‐quality stopover habitat to buffer migratory populations from climate‐induced mismatch. 7.We discuss how MFNs could be applied to diverse migratory taxa, and highlight the potential of MFNs as a tool for exploring how migrants respond to other environmental changes such as habitat loss. This article is protected by copyright. All rights reserved.
      PubDate: 2016-01-19T08:08:49.079154-05:
      DOI: 10.1111/1365-2656.12494
  • Adding constraints to predation through allometric relation of scats to
    • Authors: Stotra Chakrabarti; Yadvendradev V. Jhala, Sutirtha Dutta, Qamar Qureshi, Riaz F. Kadivar, Vishwadipsinh J. Rana
      First page: 660
      Abstract: 1.A thorough understanding of mechanisms of prey consumption by carnivores and the constraints on predation help us in evaluating the role of carnivores in an ecosystem. This is crucial in developing appropriate management strategies for their conservation and mitigating human‐carnivore conflict. Current models on optimal foraging suggest that mammalian carnivores would profit most from killing the largest prey that they can subdue with minimal risk of injury to themselves. 2.Wild carnivore diets are primarily estimated through analysis of their scats. Using extensive feeding experiments (n=68) on a wide size range (4.5 kg ‐ 130 kg) of obligate carnivores ‐ lion, leopard, jungle cat and domestic cat, we parameterize biomass models that best relate consumption to scat production. We evaluate additional constraints of gut‐fill, prey digestibility and carcass utilization on carnivory that were hereto not considered in optimal foraging studies. 3.Our results show that patterns of consumption to scat production against prey size are similar and asymptotic, contrary to established linear models, across these carnivores after accounting for the effect of carnivore size. This asymptotic, allometric relationship allowed us to develop a generalized model; biomass consumed per collectable scat/predator weight = 0.033 ‐0.025exp 4.284(prey weight/predator weight), which is applicable to all obligate carnivores to compute prey biomass consumed from scats. Our results also depict a relationship for prey digestibility which saturates at about 90% for prey larger than predator size. Carcass utilization declines exponentially with prey size. These mechanisms result in digestible biomass saturating at prey weights approximately equal to predator weight. 4.Published literature on consumption by tropical carnivores that has relied on linear biomass models is substantially biased. We demonstrate the nature of these biases by correcting diets of tiger, lion and leopard in recent publications. Our analysis suggests that consumption of medium sized prey was significantly under‐estimated, while large prey consumption was grossly over‐estimated in large carnivore diets to date. We highlight that additional constraints of prey‐ digestibility and utilization combined with escalating handling time and risks of killing large prey, make prey larger than the predator size unprofitable for obligate carnivores. This article is protected by copyright. All rights reserved.
      PubDate: 2016-03-25T07:10:49.516185-05:
      DOI: 10.1111/1365-2656.12508
  • Impacts of warming revealed by linking resource growth rates with consumer
           functional responses
    • Authors: Derek C. West; David M. Post
      First page: 671
      Abstract: Summary 1.Warming global temperatures are driving changes in species distributions, growth and timing, but much uncertainty remains regarding how climate change will alter species interactions. 2.Consumer‐Resource interactions in particular can be strongly impacted by changes to the relative performance of interacting species. While consumers generally gain an advantage over their resources with increasing temperatures, nonlinearities can change this relation near temperature extremes. 3.We use an experimental approach to determine how temperature changes between 5 and 30 °C will alter the growth of the algae Scenedesmus obliquus and the functional responses of the small bodied Daphnia ambigua and the larger D. pulicaria. 4.The impact of warming generally followed expectations, making both Daphnia species more effective grazers, with the increase in feeding rates outpacing the increases in algal growth rate. At the extremes of our temperature range, however, warming resulted in a decrease in Daphnia grazing effectiveness. Between 25 and 30°C both species of Daphnia experienced a precipitous drop in feeding rates, while algal growth rates remained high, increasing the likelihood of algal blooms in warming summer temperatures. 5.D. pulicaria performed significantly better at cold temperatures than D. ambigua, but by 20°C there was no significant difference between the two species and at 25°C D. ambigua out‐performed D. pulicaria. Warming summer temperatures will favor the smaller D. ambigua, but only over a narrow temperature range and warming beyond 25°C could open D. ambigua to invasion from tropical species. 6.By fitting our results to temperature dependent functions we develop a temperature and density dependent model which produces a metric of grazing effectiveness, quantifying the grazer density necessary to halt algal growth. This approach should prove useful for tracking the transient dynamics of other density dependent consumer‐resource interactions, such as agricultural pests and biological control agents. This article is protected by copyright. All rights reserved.
      PubDate: 2016-01-18T21:26:36.213931-05:
      DOI: 10.1111/1365-2656.12491
  • Hitting the moving target: modelling ontogenetic shifts with stable
           isotopes reveals the importance of isotopic turnover
    • First page: 681
      Abstract: 1.Ontogenetic niche shifts are widely prevalent in nature and are important in shaping the structure and dynamics of ecosystems. Stable isotope analysis is a powerful tool to assess these shifts, with δ15N providing a measure of trophic level and δ13C a measure of energy source. 2.Previous applications of stable isotopes to study ontogenetic niche shifts have not considered the appreciable time‐lag between diet and consumer tissue associated with isotopic turnover. These time‐lags introduce significant complexity into field studies of ontogenetic niche shifts. 3.Juvenile Chinook Salmon (Oncorhynchus tshawytscha) migrate from freshwater to marine ecosystems, and shift their diet from feeding primarily on invertebrates to feeding primarily on fish. This dual ontogenetic habitat and diet shift, in addition to the long time‐lag associated with isotopic turnover, suggests that there is potential for a disconnect between the prey sources that juvenile salmon are consuming, and the inferred prey sources from stable isotope analysis. 4.We developed a model that considered ontogenetic niche shifts and time‐lags associated with isotopic turnover, and compared this ‘ontogeny’ model to one that considered only isotopic turnover. We used a Bayesian framework to explicitly account for parameter uncertainty. 5.Data showed overwhelming support for the ontogeny model relative to the isotopic turnover model. Estimated variables from best model fits indicate that the ontogeny model predicts a much greater reliance on fish prey than does the stomach content data. Overall, we found that this method of quantifying ontogenetic niche shifts effectively accounted for both isotopic turnover and ontogenetic diet shifts; a finding that could be widely applicable to a variety of systems. This article is protected by copyright. All rights reserved.
      PubDate: 2016-02-16T02:20:51.740575-05:
      DOI: 10.1111/1365-2656.12504
  • Fitness consequences of early life conditions and maternal size effects in
           a freshwater top predator
    • First page: 692
      Abstract: 1.Conditions experienced in early life stages can be an important determinant of individual life histories. In fish, environmental conditions are known to affect early survival and growth, but recent studies have also emphasized maternal effects mediated by size or age. However, the relative sensitivity of the mean fitness (population growth rate λ) to different early life impacts remain largely unexplored. 2.Using a female‐based integral projection model (IPM) parameterised from unique long‐term demographic data for pike (Esox lucius), we evaluated the relative fitness consequences of different early life impacts, including i) maternal effects of length on egg weight, potentially affecting offspring (first year) survival, and ii) effects of temperature on offspring growth and survival. Of the seven vital rates defining the model, offspring survival could not be directly estimated and four scenarios were defined for this rate. 3.Elasticity analyses of the IPM were performed to calculate i) the total contribution from different lengths to the elasticity of λ to the projection kernel, and ii) the elasticity of λ to underlying variables of female current length, female offspring length at age 1, and temperature. These elasticities were decomposed into contributions from different vital rates across length. 4.Egg weight increased with female length, as expected, but the effect leveled off for the largest females. However, λ was largely insensitive to this effect, even when egg weight was assumed to have a strong effect on offspring survival. In contrast, λ was sensitive to early temperature conditions through growth and survival. Among mature females, the total elasticity of λ to the projection kernel generally increased with length. The results were robust to a wide range of assumptions. 5.These results suggest that environmental conditions experienced in early life represent a more important driver of mean population growth and fitness of pike than maternal effects of size on offspring survival.We discuss two general mechanisms underlying the weak influence of this maternal effect, suggesting that these may be general for long‐lived and highly fecund fishes. This model and results are relevant for management of long‐lived top‐predators, including many commercially important fish species. This article is protected by copyright. All rights reserved.
      PubDate: 2016-01-19T03:08:21.407067-05:
      DOI: 10.1111/1365-2656.12489
  • Age‐dependent and age‐independent sexual selection on multiple
           male traits in the lekking black grouse (Lyrurus tetrix)
    • Authors: Matti Kervinen; Christophe Lebigre, Carl D. Soulsbury
      First page: 715
      Abstract: 1.Individuals’ reproductive success is often strongly associated with their age, with typical patterns of early life reproductive improvement and late life senescence. These age‐related patterns are due to the inherent trade‐offs between life history traits competing for a limited amount of resources available to the organisms. In males, such trade‐offs are exacerbated by the resource requirements associated with the expression of costly sexual traits, leading to dynamic changes in trait expression throughout their lifespan. 2.Due to the age‐dependency of male phenotypes, the relationship between the expression of male traits and mating success can also vary with male age. Hence, using longitudinal data in a lekking species with strong sexual selection – the black grouse Lyrurus tetrix – we quantified the effects of age, lifespan and age of first lek attendance (AFL) on male annual mating success (AMS) to separate the effects of within‐individual improvement and senescence on AMS from selective (dis)appearance of certain phenotypes. Then, we used male AMS to quantify univariate and multivariate sexual selection gradients on male morphological and behavioural traits with and without accounting for age and age‐related effects of other traits. 3.Male AMS increased with age and there was no significant reproductive senescence. Most males never copulated and of the ones that did, the majority had only one successful year. Lifespan was unrelated to AMS, but early AFL tended to lead to higher AMS at ages 1 to 3. AMS was related to morphological and behavioural traits when male age was ignored. Accounting for age and age‐specific trait effects (i.e. the interaction between a trait and age) reduced the magnitude of the selection gradients and revealed that behavioural traits are under consistent sexual selection, while sexual selection on morphological traits is stronger in old males. 4.Therefore, sexual selection in black grouse operates primarily on male behaviour and morphological traits may act as additional cues to supplement female choice. These results demonstrate the multifaceted influence of age on both fitness and sexual traits and highlight the importance of accounting for such effects when quantifying sexual selection. This article is protected by copyright. All rights reserved.
      PubDate: 2016-01-22T02:46:46.498887-05:
      DOI: 10.1111/1365-2656.12496
  • Exploring the universal ecological responses to climate change in a
           univoltine butterfly
    • Authors: Phillip B. Fenberg; Angela Self, John R. Stewart, Rebecca J. Wilson, Stephen J. Brooks
      First page: 739
      Abstract: Animals with distinct life stages are often exposed to different temperatures during each stage. Thus, how temperature affects these life stages should be considered for broadly understanding the ecological consequences of climate warming on such species. For example, temperature variation during particular life stages may affect respective change in body size, phenology and geographic range, which have been identified as the “universal” ecological responses to climate change. While each of these responses has been separately documented across a number of species, it is not known whether each response occurs together within a species. The influence of temperature during particular life stages may help explain each of these ecological responses to climate change. Our goal was to determine if monthly temperature variation during particular life stages of a butterfly species can predict respective changes in body size and phenology. We also refer to the literature to assess if temperature variability during the adult stage influences range change over time. Using historical museum collections paired with monthly temperature records, we show that changes in body size and phenology of the univoltine butterfly, Hesperia comma, are partly dependent upon temporal variation in summer temperatures during key stages of their life cycle. June temperatures, which are likely to affect growth rate of the final larval instar, are important for predicting adult body size (for males only; showing a positive relationship with temperature). July temperatures, which are likely to influence the pupal stage, are important for predicting the timing of adult emergence (showing a negative relationship with temperature). Previous studies show that August temperatures, which act on the adult stage, are linked to range change. Our study highlights the importance of considering temperature variation during each life stage over historic time‐scales for understanding intraspecific response to climate change. Range edge studies of ectothermic species that have annual life cycles, long time‐series occurrence data, and associated temperature records (ideally at monthly resolutions) could be useful model systems for intraspecific tests of the universal ecological responses to climate change and for exploring interactive effects. Animals with distinct life stages experience different temperatures during each stage. Thus, how each life stage separately and collectively responds to temperature is essential for understanding the biotic consequences of climate change. Using historical data and reference to previous literature, the authors show that temperature variation during particular life stages influences body size, phenology, and the geographic range of a British butterfly.
      PubDate: 2016-02-15T01:27:28.774872-05:
      DOI: 10.1111/1365-2656.12492
  • Migratory connectivity and effects of winter temperatures on migratory
           behaviour of the European robin Erithacus rubecula: a continent‐wide
    • First page: 749
      Abstract: 1.Many partially migratory species show phenotypically divergent populations in terms of migratory behaviour, with climate hypothesized to be a major driver of such variability through its differential effects on sedentary and migratory individuals. 2.Based on long‐term (1947‐2011) bird ringing data, we analysed phenotypic differentiation of migratory behaviour among populations of the European robin Erithacus rubecula across Europe. 3.We showed that clusters of populations sharing breeding and wintering ranges varied from partial (British Isles and Western Europe, NW cluster) to completely migratory (Scandinavia and North‐Eastern Europe, NE cluster). 4.Distance migrated by birds of the NE (but not of the NW) cluster decreased through time because of a north‐eastwards shift in the wintering grounds. Moreover, when winter temperatures in the breeding areas were cold, individuals from the NE cluster also migrated longer distances, while those of the NW cluster moved over shorter distances. 5.Climatic conditions may therefore affect migratory behaviour of robins, although large geographical variation in response to climate seems to exist. This article is protected by copyright. All rights reserved.
      PubDate: 2016-01-28T10:02:50.77945-05:0
      DOI: 10.1111/1365-2656.12497
  • Socially‐mediated effects of climate change decrease survival of
           hibernating Alpine marmots
    • First page: 761
      Abstract: 1.In the context of global change, an increasing challenge is to understand the interaction between weather variables and life histories. Species‐specific life histories should condition the way climate influences population dynamics, particularly those that are associated with environmental constraints, such as lifestyles like hibernation and sociality. However, the influence of lifestyle in the response of organisms to climate change remains poorly understood. 2.Based on a 23‐year longitudinal study of the Alpine marmot, we investigated how their lifestyle, characterized by a long hibernation and a high degree of sociality, interacts with the ongoing climate change to shape temporal variation in age‐specific survival. 3.As generally reported in other hibernating species, we expected survival of Alpine marmots to be affected by the continuous lengthening of the growing season of plants more than by changes in winter conditions. We found, however, that Alpine marmots displayed lower juvenile survival over time. Colder winters associated with a thinner snow layer lowered juvenile survival, which in turn was associated with a decrease in the relative number of helpers in groups in the following years, and therefore lowered the chances of over‐winter survival of juveniles born in the most recent years. 4.Our results provide evidence that constraints on life history traits associated with hibernation and sociality caused juvenile survival to decrease over time, which might prevent Alpine marmots coping successfully with climate change. This article is protected by copyright. All rights reserved.
      PubDate: 2016-02-27T03:38:28.136509-05:
      DOI: 10.1111/1365-2656.12507
  • Intraguild predation leads to cascading effects on habitat choice,
           behaviour and reproductive performance
    • First page: 774
      Abstract: 1.Intraguild predation (IGP) is a commonly recognised mechanism influencing the community structure of predators, but the complex interactions are notoriously difficult to disentangle. The mesopredator suppression hypothesis predicts that a superpredator may either simultaneously repress two mesopredators, restrain the dominant one and thereby release the subdominant mesopredator, or elicit different responses by both mesopredators. 2.We show the outcome arising from such conditions in a three‐level predator assemblage (Eurasian eagle owl Bubo bubo L., northern goshawk Accipiter gentilis L., and common buzzard Buteo buteo L.) studied over 25 years. In the second half of the study period, the eagle owl re‐colonised the study area, thereby providing a natural experiment of superpredator introduction. We combined this setup with detailed GIS‐analysis of habitat use and a field experiment simulating intrusion by the superpredator into territories of the subdominant mesopredator, the buzzard. 3.Although population trends were positive for all three species in the assemblage, the proportion of failed breeding attempts increased significantly in both mesopredators after the superpredator re‐colonised the area. 4.We predicted that superpredator‐induced niche shifts in the dominant mesopredator may facilitate mesopredator coexistence in superpredator‐free refugia. We found significant changes in nesting habitat choice in goshawk, but not in buzzard. Since competition for enemy‐free refugia and the rapid increase in population density may have constrained niche shifts of the subdominant mesopredator, we further predicted behavioural changes in response to the superpredator. The field experiment indeed showed a significant increase in aggressive response of buzzards toward eagle owl territory intrusion over the course of ten years, probably due to phenotypic plasticity in the response towards superpredation risk. 5.Overall, our results show that intraguild predation can be a powerful force of behavioural change, simultaneously influencing habitat use and aggressiveness in predator communities. These changes might help to buffer mesopredator populations against the negative effects of intraguild predation. This article is protected by copyright. All rights reserved.
      PubDate: 2016-01-19T08:11:25.328585-05:
      DOI: 10.1111/1365-2656.12493
  • Behavioral Flexibility in Migratory Behavior in a Long‐Lived Large
    • Authors: Scott L. Eggeman; Mark Hebblewhite, Holger Bohm, Jesse Whittington, Evelyn H. Merrill
      First page: 785
      Abstract: 1.Migratory animals are predicted to enhance lifetime fitness by obtaining higher quality forage and/or reducing predation risk compared to non‐migratory conspecifics. Despite evidence for behavioral flexibility in other taxa, previous research on large mammals has often assumed that migratory behavior is a fixed behavioral trait. 2.Migratory behavior may be plastic for many species, although few studies have tested for individual‐level flexibility using long‐term monitoring of marked individuals, especially in large mammals such as ungulates. 3.We tested variability in individual migratory behavior using a ten‐year telemetry dataset of 223 adult female elk (Cervus elaphus) in the partially migratory Ya Ha Tinda population in Alberta, Canada. 4.We used net squared displacement (NSD) to classify migratory strategy for each individual elk year. Individuals switched between migrant and resident strategies at a mean rate of 15% per year, and migrants were more likely to switch than residents. We then tested how extrinsic (climate, elk/wolf abundance) and intrinsic (age) factors affected the probability of migrating, and, second, the decision to switch between migratory strategies. 5. Over 630 individual elk‐years, the probability of an individual elk migrating increased following a severe winter, in years of higher wolf abundance, and with increasing age. 6.At an individual elk level, we observed 148 switching events out of 430 possible transitions in elk monitored at least 2 years. We found switching was density‐dependent, where migrants switched to a resident strategy at low elk abundance, but residents switched more to a migrant strategy at high elk abundance. Precipitation during the previous summer had a weak carryover effect, with migrants switching slightly more following wetter summers, whereas residents showed the opposite pattern. Older migrant elk rarely switched, whereas resident elk switched more frequently to migrate at older ages. 7.Our results show migratory behavior in ungulates is an individually variable trait that can respond to intrinsic, environmental, and density‐dependent forces. Different strategies had opposing responses to density‐dependent and intrinsic drivers, providing a stabilizing mechanism for the maintenance of partial migration and demographic fitness in this population. This article is protected by copyright. All rights reserved.
      PubDate: 2016-01-20T10:05:49.391011-05:
      DOI: 10.1111/1365-2656.12495
  • Context‐dependent seed dispersal by a scatter‐hoarding corvid
    • Authors: Mario B. Pesendorfer; T. Scott Sillett, Scott A. Morrison, Alan C. Kamil
      First page: 798
      Abstract: 1.Corvids (crows, jays, magpies and nutcrackers) are important dispersers of large‐seeded plants. Studies on captive or supplemented birds suggest that they flexibly adjust their scatter‐hoarding behavior to the context of social dynamics and relative seed availability. Because many corvid‐dispersed trees show high annual variation in seed, context‐dependent foraging can have strong effects on natural corvid scatter‐hoarding behavior. 2.We investigated how seed availability and social dynamics affected scatter‐hoarding in the island scrub‐jays (Aphelocoma insularis). We quantified rates of scatter‐hoarding behaviour and territorial defense of 26 color‐marked birds over a three‐year period with variable acorn crops. 3.We tested whether caching parameters were correlated with variation in annual seed production of oaks as predicted by the predator dispersal hypothesis, which states that caching rates and distances should vary with seed abundance in ways that benefit tree fitness. We also tested whether antagonistic interactions with conspecifics would affect scatter‐hoarding adversely, as found in experimental studies. 4.Caching behavior varied with acorn availability. Caching distances correlated positively with annual acorn crop size, increasing by as much as 40% between years. Caching rates declined over time in years with small acorn crops, but increased when crops were large. Acorn foraging and caching rates were also negatively correlated with rates of territorial aggression. Overall foraging rates, however, were not associated with aggression, suggesting that reduced dispersal rates were not simply due to time constraints. 5.Our field results support laboratory findings that caching rates and distances by scatter‐hoarding corvids are context‐dependent. Furthermore, our results are consistent with predictions of the predator dispersal hypothesis, and suggest that large seed crops and social interactions among scatter‐horders affect dispersal benefits for oaks and other masting tree species. This article is protected by copyright. All rights reserved.
      PubDate: 2016-03-06T06:33:22.125153-05:
      DOI: 10.1111/1365-2656.12501
  • Parasite infection alters nitrogen cycling at the ecosystem scale
    • Authors: John Mischler; Pieter T.J. Johnson, Valerie J. McKenzie, Alan R. Townsend
      First page: 817
      Abstract: 1.Despite growing evidence that parasites often alter nutrient flows through their hosts and can comprise a substantial amount of biomass in many systems, whether endemic parasites influence ecosystem nutrient cycling, and which nutrient pathways may be important, remains conjectural. 2.A framework to evaluate how endemic parasites alter nutrient cycling across varied ecosystems requires an understanding of: (1) parasite effects on host nutrient excretion, (2) ecosystem nutrient limitation, (3) effects of parasite abundance, host density, host functional role, and host excretion rate on nutrient flows, and (4) how this infection‐induced nutrient flux compares to other pools and fluxes. Pathogens that significantly increase the availability of a limiting nutrient within an ecosystem should produce a measurable ecosystem‐scale response. 3.Here, we combined field‐derived estimates of trematode parasite infections in aquatic snails with measurements of snail excretion and tissue stoichiometry to show that parasites are capable of altering nutrient excretion in their intermediate host snails (dominant grazers). We integrated laboratory measurements of host nitrogen excretion with field‐based estimates of infection in an ecosystem model and compared these fluxes to other pools and fluxes of nitrogen as measured in the field. Eighteen nitrogen limited ponds were examined to determine if infection had a measurable effect on ecosystem‐scale nitrogen cycling. 4.Because of their low nitrogen content and high demand for host carbon, parasites accelerated the rate at which infected hosts excreted nitrogen to the water column in a dose‐response manner, thereby shifting nutrient stoichiometry and availability at the ecosystem scale. Infection‐enhanced fluxes of dissolved inorganic nitrogen were similar to other commonly important environmental sources of bioavailable nitrogen to the system. Additional field measurements within nitrogen‐limited ponds indicated that nitrogen flux rates from the periphyton to the water column in high snail density/high infection ponds were up to 50% higher than low infection ponds. 5.By altering host nutrient assimilation/excretion flexibility, parasites could play a widespread, but currently unrecognized, role in ecosystem nutrient cycling, especially when parasite and host abundances are high and hosts play a central role in ecosystem nutrient cycling. This article is protected by copyright. All rights reserved.
      PubDate: 2016-03-25T23:25:49.16194-05:0
      DOI: 10.1111/1365-2656.12505
  • Host contact and shedding patterns clarify variation in pathogen exposure
           and transmission in threatened tortoise Gopherus agassizii: implications
           for disease modeling and management
    • Authors: Christina M. Aiello; Kenneth E. Nussear, Todd C. Esque, Patrick G. Emblidge, Pratha Sah, Shweta Bansal, Peter J. Hudson
      First page: 829
      Abstract: 1.Most directly transmitted infections require some form of close contact between infectious and susceptible hosts to spread. Often disease models assume contacts are equal and use mean field estimates of transmission probability for all interactions with infectious hosts. 2.Such methods may inaccurately describe transmission when interactions differ substantially in their ability to cause infection. Understanding this variation in transmission risk may be critical to properly model and manage some infectious diseases. In this study, we investigate how varying exposure and transmission may be key to understanding disease dynamics in the threatened desert tortoise Gopherus agassizii. 3.We created heterogeneity in Mycoplasma agassizii exposure (the putative bacterial agent of a respiratory disease) by varying the duration of interactions between naturally infected and uninfected captive desert tortoises. Using qPCR, we identified new infections and compared models of transmission probability as a function of contact duration and pathogen load. We then examined the contact patterns of a wild tortoise population using proximity loggers to identify heterogeneity in contact duration. 4.The top‐ranked model predicting M. agassizii transmission included a dose term defined as the product of the number of days in proximity to an infected host and the infection level of that host. Models predicted low transmission probability for short interactions, unless the infectious host had a high load of M. agassizii: such hosts were predicted to transmit infection at higher rates with any amount of contact. We observed predominantly short‐lived interactions in a free‐ranging tortoise population and thus, expect transmission patterns in this population to vary considerably with the frequency and duration of high infection levels. 5.Mean field models may misrepresent natural transmission patterns in this and other populations depending on the distribution of high‐risk contact and shedding events. Rapid outbreaks in generally solitary species may result from changes to their naturally low‐risk contact patterns or due to increases in the frequency of severe infections or super shedding events – population characteristics that should be further investigated to develop effective management strategies. This article is protected by copyright. All rights reserved.
      PubDate: 2016-03-03T01:46:22.383429-05:
      DOI: 10.1111/1365-2656.12511
  • Temperature‐associated habitat selection in a cold‐water
           marine fish
    • Authors: Carla Freitas; Esben Moland Olsen, Halvor Knutsen, Jon Albretsen, Even Moland
      Abstract: Habitat selection is a complex process, which involves behavioural decisions guided by the multiple needs and constraints faced by individuals. Climate‐induced changes in environmental conditions may alter those trade‐offs and resulting habitat use patterns. In this study we investigated the effect of sea temperature on habitat selection and habitat use of acoustically tagged Atlantic cod (Gadus morhua) at the Norwegian Skagerrak coast. Significant relationships between ocean temperature and habitat selection and use were found. Under favourable sea temperature thresholds (< 16°C), cod selected vegetated habitats, such as eelgrass and macroalgae beds, available in shallow areas. Selection for those habitats was especially high at night, when cod tended to ascend to shallower areas, presumably to feed. Selection and use of those habitats decreased significantly as temperature rose. Under increased sea surface temperature conditions, cod were absent from vegetated shallow habitats, both during the day and night, and selected instead non‐vegetated rocky bottoms and sand habitats, available in deeper, colder areas. This study shows the dynamic nature of habitat selection and strongly suggests that cod in this region have to trade off food availability against favourable temperature conditions. Future increases in ocean temperature are expected to further influence the spatial behaviour of marine fish, potentially affecting individual fitness and population dynamics. This article is protected by copyright. All rights reserved.
      PubDate: 2015-10-17T09:14:24.047631-05:
      DOI: 10.1111/1365-2656.12458
  • A benign juvenile environment reduces the strength of antagonistic
           pleiotropy and genetic variation in the rate of senescence
    • First page: 705
      Abstract: 1.The environment can play an important role in the evolution of senescence because the optimal allocation between somatic maintenance and reproduction depends on external factors influencing life expectancy. 2.The aims of this study were to experimentally test whether environmental conditions during early life can shape senescence schedules, and if so, to examine whether variation among individuals or genotypes with respect to the degree of ageing differs across environments. 3.We tested life‐history plasticity and quantified genetic effects on the pattern of senescence across different environments within a reaction norm framework by using an experiment on the three‐spined stickleback (Gasterosteus aculeatus, Linnaeus) in which F1 families originating from a wild annual population experienced different temperature regimes. 4.Male sticklebacks that had experienced a more benign environment earlier in life subsequently reduced their investment in carotenoid‐based sexual signals early in the breeding season, and consequently senesced at a slower rate later in the season, compared to those that had developed under harsher conditions. This plasticity of ageing was genetically determined. Both antagonistic pleiotropy and genetic variation in the rate of senescence were evident only in the individuals raised in the harsher environment. 5.The experimental demonstration of genotype‐by‐environment interactions influencing the rate of reproductive senescence provides interesting insights into the role of the environment in the evolution of life‐histories. The results suggest that benign conditions weaken the scope for senescence to evolve, and that the dependence on the environment may maintain genetic variation under selection. This article is protected by copyright. All rights reserved.
      PubDate: 2015-11-12T08:07:02.056005-05:
      DOI: 10.1111/1365-2656.12468
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