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ZOOLOGY (138 journals)                     

Showing 1 - 138 of 138 Journals sorted alphabetically
Acta Herpetologica     Open Access   (Followers: 8)
Acta Theriologica     Full-text available via subscription   (Followers: 6)
Acta Zoologica     Hybrid Journal   (Followers: 7)
Acta Zoologica Cracoviensia     Free   (Followers: 2)
Acta zoológica mexicana     Open Access  
Advances in Zoology and Botany     Open Access  
African Invertebrates     Open Access   (Followers: 1)
African Journal of Herpetology     Full-text available via subscription   (Followers: 7)
African Journal of Wildlife Research     Full-text available via subscription   (Followers: 6)
African Zoology     Hybrid Journal   (Followers: 6)
American Journal of Zoological Research     Open Access   (Followers: 1)
animal     Hybrid Journal   (Followers: 3)
Animal Behaviour     Hybrid Journal   (Followers: 189)
Animal Biology     Hybrid Journal   (Followers: 9)
Animal Biology & Animal Husbandry     Open Access   (Followers: 5)
Animal Biotelemetry     Open Access   (Followers: 1)
Animal Genetics     Hybrid Journal   (Followers: 8)
Animal Migration     Open Access   (Followers: 1)
Animal Studies Journal     Open Access   (Followers: 8)
Annales Zoologici     Full-text available via subscription   (Followers: 1)
Annales Zoologici Fennici     Open Access   (Followers: 1)
Annals of Animal Science     Open Access   (Followers: 1)
Annals of the Ditsong National Museum of Natural History     Full-text available via subscription   (Followers: 3)
Annual Review of Animal Biosciences     Full-text available via subscription   (Followers: 5)
Anthrozoos : A Multidisciplinary Journal of The Interactions of People & Animals     Hybrid Journal   (Followers: 9)
Applied Animal Behaviour Science     Hybrid Journal   (Followers: 19)
Applied Entomology and Zoology     Partially Free   (Followers: 3)
Aquatic Mammals     Full-text available via subscription   (Followers: 8)
Aquatic Sciences     Hybrid Journal   (Followers: 13)
Arquivos de Ciências Veterinárias e Zoologia da UNIPAR     Open Access  
Arquivos de Zoologia     Open Access  
Arthropod Management Tests     Hybrid Journal   (Followers: 2)
Asian Journal of Animal and Veterinary Advances     Open Access   (Followers: 8)
Australian Journal of Zoology     Hybrid Journal   (Followers: 1)
Bangladesh Journal of Zoology     Open Access  
Bioacoustics : The International Journal of Animal Sound and its Recording     Partially Free   (Followers: 2)
Biodiversidade     Open Access  
Bird Conservation International     Hybrid Journal   (Followers: 23)
Bird Study     Full-text available via subscription   (Followers: 26)
BMC Zoology     Open Access  
Brazilian Journal of Veterinary Research and Animal Science     Open Access   (Followers: 7)
British Birds     Full-text available via subscription   (Followers: 27)
Bulletin of the Museum of Comparative Zoology     Full-text available via subscription   (Followers: 2)
Canadian Journal of Animal Science     Hybrid Journal   (Followers: 5)
Canadian Journal of Zoology     Hybrid Journal   (Followers: 17)
Canadian Zooarchaeology / Zooarchéologie canadienne     Open Access   (Followers: 2)
Contributions to Zoology     Open Access   (Followers: 3)
Current Zoology     Full-text available via subscription   (Followers: 1)
Der Zoologische Garten     Full-text available via subscription   (Followers: 2)
Ecology of Freshwater Fish     Hybrid Journal   (Followers: 17)
European Journal of Taxonomy     Open Access   (Followers: 4)
European Zoological Journal     Open Access  
Euscorpius     Open Access   (Followers: 1)
EvoDevo     Open Access   (Followers: 3)
Fish and Fisheries     Hybrid Journal   (Followers: 32)
Frontiers in Zoology     Open Access   (Followers: 6)
Graellsia     Open Access   (Followers: 1)
Herpetology Notes     Open Access   (Followers: 6)
Hystrix, the Italian Journal of Mammalogy     Open Access   (Followers: 1)
i-Perception     Open Access   (Followers: 3)
Iheringia. Série Zoologia     Open Access   (Followers: 1)
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: 5)
Invertebrate Reproduction & Development     Hybrid Journal   (Followers: 4)
Italian Journal of Animal Science     Open Access   (Followers: 3)
Italian Journal of Zoology     Hybrid Journal   (Followers: 2)
Journal of Agrobiology     Open Access   (Followers: 3)
Journal of Animal Ecology     Hybrid Journal   (Followers: 68)
Journal of Animal Physiology and Animal Nutrition     Hybrid Journal   (Followers: 6)
Journal of Apicultural Science     Open Access   (Followers: 2)
Journal of Applied Animal Research     Hybrid Journal   (Followers: 5)
Journal of Basic & Applied Zoology : Physiology     Open Access   (Followers: 2)
Journal of Experimental Zoology Part A: Ecological Genetics and Physiology     Hybrid Journal   (Followers: 4)
Journal of Experimental Zoology Part B : Molecular and Developmental Evolution     Hybrid Journal   (Followers: 2)
Journal of Freshwater Ecology     Hybrid Journal   (Followers: 14)
Journal of Herpetology     Full-text available via subscription   (Followers: 16)
Journal of Morphology     Hybrid Journal   (Followers: 6)
Journal of Threatened Taxa     Open Access  
Journal of Venomous Animals and Toxins     Open Access   (Followers: 5)
Journal of Venomous Animals and Toxins including Tropical Diseases     Open Access   (Followers: 1)
Journal of Wildlife Management     Hybrid Journal   (Followers: 40)
Journal of Zoological Systematics and Evolutionary Research     Hybrid Journal   (Followers: 4)
Journal of Zoology     Hybrid Journal   (Followers: 28)
Laboratory Animals     Hybrid Journal   (Followers: 15)
Mammalia     Hybrid Journal   (Followers: 5)
Mastozoología Neotropical     Open Access  
Monographs of the Transvaal Museum     Full-text available via subscription  
Natural History Sciences     Hybrid Journal   (Followers: 3)
New Zealand Journal of Zoology     Hybrid Journal   (Followers: 11)
Papéis Avulsos de Zoologia     Open Access  
Parasite     Open Access   (Followers: 4)
Polish Journal of Entomology     Open Access   (Followers: 4)
Primate Biology     Open Access   (Followers: 1)
Protist Genomics     Open Access   (Followers: 1)
Redia : Journal of Zoology     Open Access   (Followers: 1)
Remote Sensing in Ecology and Conservation     Open Access   (Followers: 20)
Research in Zoology     Open Access   (Followers: 2)
Revista Brasileira de Reprodução Animal     Open Access  
Revista de Biología Marina y Oceanografía     Open Access  
Revista de Educação Continuada em Medicina Veterinária e Zootecnia     Open Access  
Revista de Zoologia     Open Access   (Followers: 1)
Russian Journal of Herpetology     Full-text available via subscription   (Followers: 4)
Scientific Journal of Animal Science     Open Access   (Followers: 6)
Scientific Journal of Zoology     Open Access   (Followers: 5)
SHILAP Revista de Lepidopterologia     Open Access   (Followers: 2)
Skeletal Muscle     Open Access   (Followers: 1)
South American Journal of Herpetology     Full-text available via subscription   (Followers: 6)
Sri Lanka Journal of Aquatic Sciences     Open Access   (Followers: 1)
Therya     Open Access  
Travaux du Muséum National d’Histoire Naturelle “Grigore Antipa”     Open Access  
Tropical Zoology     Partially Free   (Followers: 3)
University Journal of Zoology, Rajshahi University     Open Access  
Veterinária e Zootecnia     Open Access  
Waterbirds     Full-text available via subscription   (Followers: 10)
Wildlife Society Bulletin     Hybrid Journal   (Followers: 8)
World Rabbit Science     Open Access  
Zoo Biology     Hybrid Journal   (Followers: 10)
ZooKeys     Open Access   (Followers: 6)
Zoologia     Open Access  
Zoologia (Curitiba)     Open Access   (Followers: 1)
Zoologica Poloniae : The Journal of Polish Zoological Society     Open Access   (Followers: 1)
Zoologica Scripta     Hybrid Journal   (Followers: 4)
Zoological Journal of the Linnean Society     Hybrid Journal   (Followers: 15)
Zoological Letters     Open Access   (Followers: 1)
Zoological Science     Full-text available via subscription   (Followers: 3)
Zoological Studies     Open Access   (Followers: 2)
Zoologische Mededelingen     Open Access   (Followers: 1)
Zoologischer Anzeiger - A Journal of Comparative Zoology     Hybrid Journal   (Followers: 1)
Zoologist (The)     Full-text available via subscription   (Followers: 1)
Zoology     Hybrid Journal   (Followers: 6)
Zoology and Ecology     Hybrid Journal   (Followers: 5)
Zoomorphology     Hybrid Journal   (Followers: 3)
Zoosystematics and Evolution - Mitteilungen Aus Dem Museum Fur Naturkunde Zu Berlin     Open Access   (Followers: 1)


Journal Cover Journal of Animal Ecology
  [SJR: 3.359]   [H-I: 119]   [68 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  [1597 journals]
  • More invaders do not result in heavier impacts: the effects of nonnative
           bullfrogs on native anurans are mitigated by high densities of nonnative
    • Authors: Xuan Liu; Supen Wang, Zunwei Ke, Chaoyuan Cheng, Yihua Wang, Fang Zhang, Feng Xu, Xianping Li, Xu Gao, Changnan Jin, Wei Zhu, Shaofei Yan, Yiming Li
      Abstract: 1.With accelerating species introductions in an era of globalization, co‐occurring alien species have become increasingly common. Understanding the combined ecological impacts of multiple invaders is not only crucial for wildlife managers attempting to ameliorate biodiversity loss but also provides key insights into invasion success and species coexistence mechanisms in natural ecosystems. Compared with much attentions given to single invader impacts, little is known about the impacts of multiple co‐occurring invaders.2.The American bullfrog (Lithobates catesbeianus = Rana catesbeiana) and the red swamp crayfish (Procambarus clarkii) are two aquatic invasive species in many different areas of the globe. They co‐exist with native anurans in a variety of permanent lentic waters, which provide an ideal model system to explore the combined effects of multiple invaders from different trophic levels on native species.3.Based on a global diet analysis covering 34 native and invasive bullfrog populations, and data from 10‐year field surveys across 157 water bodies in the Zhoushan Archipelago, China, we observed a reduced impact of bullfrogs on native anurans at high crayfish densities when the two invaders co‐occurred.4.The global diet analysis showed that crayfish occurrence reduced the number of native anuran prey consumed by bullfrogs in both native and invasive populations. After accounting for pseudoreplication of different observations among water bodies, islands, and survey time, model averaging analyses based on generalized linear mixed models (GLMMs) showed a negative relationship between bullfrog density and native anuran densities for field observations of invasive bullfrogs alone and co‐invaded observations with low crayfish density. However, this negative relationship disappeared when the two invaders co‐occurred with high crayfish density. Structural equation modeling (SEM) analyses further validated that the impacts of bullfrogs on native frogs were mitigated by the negative interactions between crayfish and bullfrogs.5.Our results provide novel evidence of a density‐dependent antagonistic effect of two sympatric invaders from different trophic levels on native species. This study highlights the importance of considering complex interactions among co‐invaders and native species when prioritizing conservation and management actions and will facilitate the development of a more precise framework to predict invasion impacts.This article is protected by copyright. All rights reserved.
      PubDate: 2017-12-28T00:10:34.386105-05:
      DOI: 10.1111/1365-2656.12793
  • Dynamic occupancy modeling reveals a hierarchy of competition among
           fishers, gray foxes, and ringtails
    • Authors: David S. Green; Sean M. Matthews, Robert C. Swiers, Richard L. Callas, J. Scott Yaeger, Stuart Farber, Michael K. Schwartz, Roger A. Powell
      Abstract: 1.Determining how species coexist is critical for understanding functional diversity, niche partitioning and interspecific interactions. Identifying the direct and indirect interactions among sympatric carnivores that enable their coexistence are particularly important to elucidate because they are integral for maintaining ecosystem function.2.We studied the effects of removing 9 fishers (Pekania pennanti) on their population dynamics and used this perturbation to elucidate the interspecific interactions among fishers, gray foxes (Urocyon cinereoargenteus), and ringtails (Bassariscus astutus). Gray foxes (family: Canidae) are likely to compete with fishers due to their similar body sizes and dietary overlap, and ringtails (family: Procyonidae), like fishers, are semi‐arboreal species of conservation concern. We used spatial capture‐recapture to investigate fisher population numbers and dynamic occupancy models that incorporated interspecific interactions to investigate the effects members of these species had on the colonization and persistence of each other's site occupancy.3.The fisher population showed no change in density for up to three years following the removals of fishers for translocations. In contrast, fisher site occupancy decreased in the years immediately following the translocations. During this same time period, site occupancy by gray foxes increased and remained elevated through the end of the study.4.We found a complicated hierarchy among fishers, foxes, and ringtails. Fishers affected gray fox site persistence negatively but had a positive effect on their colonization. Foxes had a positive effect on ringtail site colonization. Thus, fishers were the dominant small carnivore where present and negatively affected foxes directly and ringtails indirectly.5.Coexistence among the small carnivores we studied appears to reflect dynamic spatial partitioning. Conservation and management efforts should investigate how intraguild interactions may influence the recolonization of carnivores to previously occupied landscapes.This article is protected by copyright. All rights reserved.
      PubDate: 2017-12-28T00:00:41.645473-05:
      DOI: 10.1111/1365-2656.12791
  • Rethinking ‘normal’: The role of stochasticity in the phenology of a
           synchronously breeding seabird
    • Authors: Casey Youngflesh; Stephanie Jenouvrier, Jefferson T. Hinke, Lauren DuBois, Judy St. Leger, Wayne Z. Trivelpiece, Susan G. Trivelpiece, Heather J. Lynch
      Abstract: 1.Phenological changes have been observed in a variety of systems over the past century. There is concern that, as a consequence, ecological interactions are becoming increasingly mismatched in time, with negative consequences for ecological function.2.Significant spatial heterogeneity (inter‐site) and temporal variability (inter‐annual) can make it difficult to separate intrinsic, extrinsic, and stochastic drivers of phenological variability. The goal of this study was to understand the timing and variability of breeding phenology of Adélie penguins under fixed environmental conditions, and to use those data to identify a ‘null model’ appropriate for disentangling the sources of variation in wild populations.3.Data on clutch initiation were collected from both wild and captive populations of Adélie penguins. Clutch initiation in the captive population was modeled as a function of year, individual, and age to better understand phenological patterns observed in the wild population.4.Captive populations displayed as much inter‐annual variability in breeding phenology as wild populations, suggesting that variability in breeding phenology is the norm and thus may be an unreliable indicator of environmental forcing. The distribution of clutch initiation dates was found to be moderately asymmetric (right skewed) both in the wild and in captivity, consistent with the pattern expected under social facilitation.5.The role of stochasticity in phenological processes has heretofore been largely ignored. However, these results suggest that inter‐annual variability in breeding phenology can arise independent of any environmental or demographic drivers and that synchronous breeding can enhance inherent stochasticity. This complicates efforts to relate phenological variation to environmental variability in the wild. Accordingly, we must be careful to consider random forcing in phenological processes, lest we fit models to data dominated by random noise. This is particularly true for colonial species where breeding synchrony may outweigh each individual's effort to time breeding with optimal environmental conditions. Our study highlights the importance of identifying appropriate null models for studying phenology.This article is protected by copyright. All rights reserved.
      PubDate: 2017-12-26T00:05:30.543788-05:
      DOI: 10.1111/1365-2656.12790
  • Disease implications of animal social network structure: a synthesis
           across social systems
    • Authors: Pratha Sah; Janet Mann, Shweta Bansal
      Abstract: 1.The disease costs of sociality have largely been understood through the link between group size and transmission. However, infectious disease spread is driven primarily by the social organization of interactions in a group and not its size.2.We used statistical models to review the social network organization of 47 species, including mammals, birds, reptiles, fish and insects by categorizing each species into one of three social systems, relatively solitary, gregarious and socially hierarchical. Additionally, using computational experiments of infection spread, we determined the disease costs of each social system.3.We find that relatively solitary species have large variation in number of social partners, that socially hierarchical species are the least clustered in their interactions, and that social networks of gregarious species tend to be the most fragmented. However, these structural differences are primarily driven by weak connections, which suggests that different social systems have evolved unique strategies to organize weak ties.4.Our synthetic disease experiments reveal that social network organization can mitigate the disease costs of group living for socially hierarchical species when the pathogen is highly transmissible. In contrast, highly transmissible pathogens cause frequent and prolonged epidemic outbreaks in gregarious species.5.We evaluate the implications of network organization across social systems despite methodological challenges, and our findings offer new perspective on the debate about the disease costs of group living. Additionally, our study demonstrates the potential of meta‐analytic methods in social network analysis to test ecological and evolutionary hypotheses on cooperation, group living, communication, and resilience to extrinsic pressures.This article is protected by copyright. All rights reserved.
      PubDate: 2017-12-15T21:10:29.498809-05:
      DOI: 10.1111/1365-2656.12786
  • A camera‐based method for estimating absolute density in animals
           displaying home range behaviour
    • Authors: Andrea Campos-Candela; Miquel Palmer, Salvador Balle, Josep Alós
      Abstract: 1.The measurement of animal density may take advantage of recent technological achievements in wildlife video recording. Fostering the theoretical links between the patterns depicted by cameras and absolute density is required to exploit this potential.2.We explore the applicability of the Hutchinson‐Waser's postulate (i.e., when animal density is stationary at a given temporal and spatial scale, the absolute density is given by the average number of animals counted per frame), which is a counter‐intuitive statement for most ecologists and managers who are concerned with counting the same individual more than once. We aimed to reconcile such skepticism for animals displaying home range behaviour.3.The specific objectives of this paper are to generalize the Hutchinson‐Waser's postulate for animals displaying home range behaviour and to propose a Bayesian implementation to estimate density from counts per frame using video cameras.4.Accuracy and precision of the method was evaluated by means of computer simulation experiments. Specifically, six animal archetypes displaying well‐contrasted movement features were considered. The simulation results demonstrate that density could be accurately estimated after an affordable sampling effort (i.e., number of cameras and deployment time) for a great number of animals across taxa.5.The proposed method may complement other conventional methods for estimating animal density. The major advantages are that identifying an animal at the individual level and precise knowledge on how animals move are not needed, and that density can be estimated in a single survey. The method can accommodate conventional camera trapping data. The major limitations are related to some implicit assumptions of the underlying model: the home range centres should be homogeneously distributed, the detection probability within the area surveyed by the camera should be known, and animals should move independently to one another. Further improvements for circumventing these limitations are discussed.This article is protected by copyright. All rights reserved.
      PubDate: 2017-12-15T03:37:49.199487-05:
      DOI: 10.1111/1365-2656.12787
  • Social behaviour and gut microbiota in red-bellied lemurs (Eulemur
           rubriventer): In search of the role of immunity in the evolution of
    • Authors: Aura Raulo; Lasse Ruokolainen, Avery Lane, Katherine Amato, Rob Knight, Steven Leigh, Rebecca Stumpf, Bryan White, Karen E. Nelson, Andrea L. Baden, Stacey R. Tecot
      Abstract: Vertebrate gut microbiota form a key component of immunity and a dynamic link between an individual and the ecosystem. Microbiota might play a role in social systems as well, because microbes are transmitted during social contact and can affect host behaviour.Combining methods from behavioural and molecular research, we describe the relationship between social dynamics and gut microbiota of a group-living cooperative species of primate, the red-bellied lemur (Eulemur rubriventer). Specifically, we ask whether patterns of social contact (group membership, group size, position in social network, individual sociality) are associated with patterns of gut microbial composition (diversity and similarity) between individuals and across time.Red-bellied lemurs were found to have gut microbiota with slight temporal fluctuations and strong social group-specific composition. Contrary to expectations, individual sociality was negatively associated with gut microbial diversity. However, position within the social network predicted gut microbial composition.These results emphasize the role of the social environment in determining the microbiota of adult animals. Since social transmission of gut microbiota has the potential to enhance immunity, microbiota might have played an escalating role in the evolution of sociality.The authors show that composition of gut microbial communities reflect the social environment of Red-bellied lemurs: Individuals spending more time together in close physical contact share similar gut microbiota and most sociable individuals have distinct gut microbial communities. This reveals a new way by which social contact can modify individuals: Touch leads to sharing bacteria that have the potential to synchronize physiological processes.
      PubDate: 2017-12-05T00:00:02.566637-05:
      DOI: 10.1111/1365-2656.12781
  • A computer vision for animal ecology
    • Authors: Ben G. Weinstein
      Abstract: 1.A central goal of animal ecology is to observe species in the natural world. The cost and challenge of data collection often limit the breadth and scope of ecological study. Ecologists often use image capture to bolster data collection in time and space. However, the ability to process these images remains a bottleneck.2.Computer vision can greatly increase the efficiency, repeatability, and accuracy of image review. Computer vision uses image features, such as color, shape, and texture to infer image content.3.I provide a brief primer on ecological computer vision to outline its goals, tools and applications to animal ecology.4.I reviewed 187 existing applications of computer vision and divided articles into ecological description, counting, and identity tasks.5.I discuss recommendations for enhancing the collaboration between ecologists and computer scientists and highlight areas for future growth of automated image analysis.This article is protected by copyright. All rights reserved.
      PubDate: 2017-11-29T05:42:05.72346-05:0
      DOI: 10.1111/1365-2656.12780
  • A practical guide for inferring reliable dominance hierarchies and
           estimating their uncertainty
    • Authors: Alfredo Sánchez-Tójar; Julia Schroeder, Damien Roger Farine
      Abstract: 1.Many animal social structures are organized hierarchically, with dominant individuals monopolizing resources. Dominance hierarchies have received great attention from behavioural and evolutionary ecologists.2.There are many methods for inferring hierarchies from social interactions. Yet, there are no clear guidelines about how many observed dominance interactions (i.e. sampling effort) are necessary for inferring reliable dominance hierarchies, nor are there any established tools for quantifying their uncertainty.3.In this study, we simulate interactions (winners and losers) in scenarios of varying steepness (the probability that a dominant defeats a subordinate based on their difference in rank). Using these data, we (1) quantify how the number of interactions recorded and the steepness of the hierarchy affect the performance of five methods for inferring hierarchies, (2) propose an amendment that improves the performance of a popular method, and (3) suggest two easy procedures to measure uncertainty and steepness in the inferred hierarchy.4.We find that the ratio of interactions to individuals required to infer reliable hierarchies is surprisingly low, but depends on the steepness of the hierarchy and the method used. We show that David's score and our novel randomized Elo‐rating are the best methods when hierarchies are not extremely steep, where the original Elo‐rating, the I&SI and the recently described ADAGIO perform less well. In addition, we show that two simple methods can be used to estimate uncertainty at the individual and group level, and that the randomized Elo‐rating repeatability provides researchers with a standardized measure valid for comparing the steepness of different hierarchies. We provide several worked examples to guide researchers interested in studying dominance hierarchies.5.Methods for inferring dominance hierarchies are relatively robust, even when the ratio of observed interactions to individuals is as low as 10 to 20. However, we suggest that implementing simple procedures for estimating uncertainty will benefit researchers, while quantifying the shape of the dominance hierarchy will provide new insights into the social structure of the study organisms.This article is protected by copyright. All rights reserved.
      PubDate: 2017-11-27T08:35:47.595789-05:
      DOI: 10.1111/1365-2656.12776
  • Do host‐associated gut microbiota mediate the effect of an herbicide on
           disease risk in frogs'
    • Authors: Sarah A. Knutie; Caitlin R. Gabor, Kevin D. Kohl, Jason R. Rohr
      Abstract: 1.Environmental stressors, such as pollutants, can increase disease risk in wildlife. For example, the herbicide atrazine affects host defenses (e.g. resistance and tolerance) of the amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd), but the mechanisms for these associations are not always clear. Given that pollutants can alter the gut microbiota of hosts, which in turn can affect their health and immune systems, one potential mechanism by which pollutants could increase infection risk is by influencing host‐associated microbiota.2.Here, we test whether early‐life exposure to the estimated environmental concentration (EEC; 200 μg/L) of atrazine affects the gut bacterial composition of Cuban tree frog (Osteopilus septentrionalis) tadpoles and adults and whether any atrazine‐induced change in community composition might affect host defenses against Bd. We also determine whether early‐life changes in the stress hormone corticosterone affect gut microbiota by experimentally inhibiting corticosterone synthesis with metyrapone.3.With the exception of changing the relative abundances of two bacterial genera in adulthood, atrazine did not affect gut bacterial diversity or community composition of tadpoles (in vivo or in vitro) or adults. Metyrapone did not significantly affect bacterial diversity of tadpoles, but significantly increased bacterial diversity of adults.4.Gut bacterial diversity during Bd exposure did not predict host tolerance or resistance to Bd intensity in tadpoles or adults. However, early‐life bacterial diversity negatively predicted Bd intensity as adult frogs. Specifically, Bd intensity as adults was associated negatively with the relative abundance of phylum Fusobacteria in the guts of tadpoles.5.Our results suggest that the effect of atrazine on Bd infection risk is not mediated by host‐associated microbiota because atrazine does not affect microbiota of tadpoles or adults. However, host‐associated microbes seem important in host resistance to Bd because the early‐life microbiota, during immune system development, predicted later‐life infection risk with Bd. Overall, our study suggests that increasing gut bacterial diversity and relative abundances of Fusobacteria might have lasting positive effects on amphibian health.This article is protected by copyright. All rights reserved.
      PubDate: 2017-11-27T08:31:09.366194-05:
      DOI: 10.1111/1365-2656.12769
  • Why are tropical mountain passes ‘low’ for some species' Genetic
           and stable‐isotope tests for differentiation, migration, and expansion
           in elevational generalist songbirds
    • Authors: Chauncey R. Gadek; Seth D. Newsome, Elizabeth J. Beckman, Andrea N. Chavez, Spencer C. Galen, Emil Bautista, Christopher C. Witt
      Abstract: 1.Most tropical bird species have narrow elevational ranges, likely reflecting climatic specialization. This is consistent with Janzen's Rule, the tendency for mountain passes to be effectively ‘higher’ in the tropics. Hence, those few tropical species that occur across broad elevational gradients (elevational generalists) represent a contradiction to Janzen's Rule.2.Here we aim to address the following questions. Are elevational generalists being sundered by diversifying selection along the gradient' Does elevational movement cause these species to resist diversification or specialization' Have they recently expanded, suggesting that elevational generalism is short‐lived in geological time'3.To answer these questions, we tested for differentiation, movement, and expansion in four elevational generalist songbird species on the Andean west slope. We used morphology and mtDNA to test for genetic differentiation between high‐ and low‐elevation populations. To test for elevational movements, we measured hydrogen isotope (δ2H) values of metabolically inert feathers and metabolically active liver.4.Morphology differed for House Wren (Troglodytes aedon) and Hooded Siskin (Spinus magellanicus), but not for Cinereous Conebill (Conirostrum cinereum) and Rufous‐collared Sparrow (Zonotrichia capensis), respectively. mtDNA was structured by elevation only in Z. capensis. δ2H data indicated elevational movements by two tree‐ and shrub‐foraging species with moderate‐to‐high vagility (C. cinereum and S. magellanicus), and sedentary behavior by two terrestrial‐foraging species with low‐to‐moderate vagility (T. aedon and Z. capensis). In S. magellanicus, elevational movements and lack of mtDNA structure contrast with striking morphological divergence, suggesting strong diversifying selection on body proportions across the ~50 km gradient. All species except C. cinereum exhibited mtDNA‐haplotype variation consistent with recent population expansion across the elevational gradient, potentially concurrent with Holocene anthropogenic habitat conversion for agriculture.5.In different ways, each species defies the tendency for tropical birds to have long‐term stable distributions and sedentary habits. We conclude that tropical elevational generalism is rare due to evolutionary instability.This article is protected by copyright. All rights reserved.
      PubDate: 2017-11-27T08:31:02.774617-05:
      DOI: 10.1111/1365-2656.12779
  • Host effects on microbiota community assembly
    • Authors: Kathrin Näpflin; Paul Schmid-Hempel
      Abstract: 1.To what extent host‐associated microbiota assembly is driven by host selection or simply by happenstance remains an open question in microbiome research.2.Here, we take a first step towards elucidating the relative importance of host selection on the establishing gut microbial community in an ecologically relevant organism.3.We presented germ‐free bumblebee, Bombus terrestris, workers from ten colonies with a “global” microbial species pool comprised of an equal mixture of the gut microbiota of all colonies.4.By means of 16S amplicon sequencing, we found that while overall microbiota community composition was generally shifted between pool‐exposed workers compared to workers that naturally acquired their gut microbiota, but that the specific composition of the established microbiota also depended on colony identity (e.g. genetic background).5.Because the microbiota is protective against parasite infection in this system, variation in the filtering of a beneficial microbial community can have important consequences for host resistance and eventual co‐evolution with parasites.This article is protected by copyright. All rights reserved.
      PubDate: 2017-11-13T05:15:48.961259-05:
      DOI: 10.1111/1365-2656.12768
  • Using host species traits to understand the consequences of resource
           provisioning for host–parasite interactions
    • Authors: Daniel J. Becker; Daniel G. Streicker, Sonia Altizer
      Abstract: 1.Supplemental food provided to wildlife by human activities can be more abundant and predictable than natural resources, and subsequent changes to wildlife ecology can have profound impacts on host–parasite interactions. Identifying traits of species associated with increases or decreases in infection outcomes with resource provisioning could improve assessments of wildlife most prone to disease risks in changing environments.2.We conducted a phylogenetic meta‐analysis of 342 host–parasite interactions across 56 wildlife species and three broad taxonomic groups of parasites to identify host‐level traits that influence whether provisioning is associated with increases or decreases in infection.3.We predicted that dietary generalists that capitalize on novel food would show greater infection in provisioned habitats owing to population growth and food‐borne exposure to contaminants and parasite infectious stages. Similarly, species with fast life histories could experience stronger demographic and immunological benefits from provisioning that affect parasite transmission. We also predicted that wide‐ranging and migratory behaviors could increase infection risks with provisioning if concentrated and non‐seasonal foods promote dense aggregations that increase exposure to parasites.4.We found that provisioning increased infection with bacteria, viruses, fungi, and protozoa (i.e., microparasites) most for wide‐ranging, dietary generalist host species. Effect sizes for ectoparasites were also highest for host species with large home ranges but were instead lowest for dietary generalists. In contrast, the type of provisioning was a stronger correlate of infection outcomes for helminths than host species traits.5.Our analysis highlights host traits related to movement and feeding behavior as important determinants of whether species experience greater infection with supplemental feeding. These results could help prioritize monitoring wildlife with particular trait profiles in anthropogenic habitats to reduce infectious disease risks in provisioned populations.This article is protected by copyright. All rights reserved.
      PubDate: 2017-11-13T05:15:39.853121-05:
      DOI: 10.1111/1365-2656.12765
  • Understanding the role of parasites in food webs using the group model
    • Authors: Matthew J. Michalska-Smith; Elizabeth L. Sander, Mercedes Pascual, Stefano Allesina
      Abstract: 1.Parasites are ubiquitous and have been shown to influence macroscopic measures of ecological network structure, such as connectance and robustness, as well as local structure, such as subgraph frequencies. Nevertheless, they are often underrepresented in ecological studies due to their small size and often complex life cycles.2.We consider whether or not parasites play structurally unique roles in ecological networks; that is, can we distinguish parasites from other species using network structure alone'3.We partition the species in a community statistically using the group model, and we test whether or not parasites tend to cluster in their own groups, using a measure of “imbalance.”4.We find that parasites form highly imbalanced groups, and that concomitant predation, in which a predator consumes a prey and its parasites, but not the number of interactions, improves the group model's ability to distinguish parasites from non‐parasites.5.This work demonstrates that parasites and non‐parasites interact in networks in statistically distinct ways, and that these differences are partly, but not entirely, due to the existence of concomitant predation.This article is protected by copyright. All rights reserved.
      PubDate: 2017-11-08T21:41:04.488107-05:
      DOI: 10.1111/1365-2656.12782
  • Experimental investigation of alternative transmission functions:
           quantitative evidence for the importance of non‐linear transmission
           dynamics in host‐parasite systems
    • Authors: Sarah A. Orlofske; Samuel M. Flaxman, Maxwell B. Joseph, Andy Fenton, Brett A. Melbourne, Pieter T.J. Johnson
      Abstract: 1.Understanding pathogen transmission is crucial for predicting and managing disease. Nonetheless, experimental comparisons of alternative functional forms of transmission remain rare, and those experiments that are conducted are often not designed to test the full range of possible forms.2.To differentiate among ten candidate transmission functions, we used a novel experimental design in which we independently varied four factors—duration of exposure, numbers of parasites, numbers of hosts, and parasite density—in laboratory infection experiments.3.We used interactions between amphibian hosts and trematode parasites as a model system and all candidate models incorporated parasite depletion. An additional manipulation involving anesthesia addressed the effects of host behaviour on transmission form.4.Across all experiments, non‐linear transmission forms involving either a power law or a negative binomial function were the best‐fitting models and consistently outperformed the linear density‐dependent and density‐independent functions. By testing previously published data for two other host‐macroparasite systems, we also found support for the same non‐linear transmission forms.5.Although manipulations of parasite density are common in transmission studies, the comprehensive set of variables tested in our experiments revealed that variation in density alone was least likely to differentiate among competing transmission functions. Across host‐pathogen systems, non‐linear functions may often more accurately represent transmission dynamics and thus provide more realistic predictions for infection.This article is protected by copyright. All rights reserved.
      PubDate: 2017-11-07T06:20:23.819423-05:
      DOI: 10.1111/1365-2656.12783
  • Active migration is associated with specific and consistent changes to gut
           microbiota in Calidris shorebirds
    • Authors: Alice Risely; David Waite, Beata Ujvari, Bethany Hoye, Marcel Klaassen
      Abstract: 1.Gut microbes are increasingly recognised for their role in regulating an animal's metabolism and immunity. However, identifying repeatable associations between host physiological processes and their gut microbiota has proved challenging, in part because microbial communities often respond stochastically to host physiological stress (e.g. fasting, forced exercise or infection).2.Migratory birds provide a valuable system in which to test host‐microbe interactions under physiological extremes because these hosts are adapted to predictable metabolic and immunological challenges as they undergo seasonal migrations, including temporary gut atrophy during long‐distance flights. These physiological challenges may either temporarily disrupt gut microbial ecosystems, or, alternatively, promote predictable host‐microbe associations during migration.3.To determine the relationship between migration and gut microbiota, we compared gut microbiota composition between migrating and non‐migrating (‘resident’) conspecific shorebirds sharing a flock. We performed this across two sandpiper species, Calidris ferruginea and Calidris ruficollis, in north‐western Australia, and an additional C. ruficollis population 3000 km away in southern Australia.4.We found that migrants consistently had higher abundances of the bacterial genus Corynebacterium (average 28% abundance) compared to conspecific residents (average < 1% abundance), with this effect holding across both species and sites. However, other than this specific association, community structure and diversity was almost identical between migrants and residents, with migration status accounting for only 1% of gut community variation when excluding Corynebacterium.5.Our findings suggest a consistent relationship between Corynebacterium and Calidris shorebirds during migration, with further research required to identify causal mechanisms behind the association, and to elucidate functionality to the host. However, outside this specific association, migrating shorebirds broadly maintained gut community structure, which may allow them to quickly recover gut function after a migratory flight. This study provides a rare example of a repeatable and specific response of the gut microbiota to a major physiological challenge across two species and two distant populations.This article is protected by copyright. All rights reserved.
      PubDate: 2017-11-07T06:17:16.994462-05:
      DOI: 10.1111/1365-2656.12784
  • Resistance and tolerance: the role of nutrients on pathogen dynamics and
           infection outcomes in an insect host
    • Authors: Charlotte V. L. Miller; Sheena C. Cotter
      Abstract: 1.Tolerance and resistance are the two ways in which hosts can lessen the effects of infection. Tolerance aims to minimise the fitness effects resulting from incumbent pathogen populations, whereas resistance aims to reduce the pathogen population size within the host. While environmental impacts on resistance have been extensively recorded their impacts on variation in tolerance are virtually unexplored.2.Here we ask how the environment, namely the host diet, influences the capacity of an organism to tolerate and resist infection, using a model host‐parasite system, the burying beetle, Nicrophorus vespilloides and the entomopathogenic bacteria, Photorhabdus luminescens.3.We first considered dose‐responses and pathogen dynamics within the host, and compared our findings to responses known from other host species. We then investigated how investment in tolerance and resistance changed under different nutritional regimes. Beetles were maintained on one of five diets that varied in their ratio of protein to fat for 48 hours and then injected with P. luminescens. Survival was monitored and the phenoloxidase (PO) response and bacterial load at 24 hours post infection were ascertained.4.The dose required to kill 50% of individuals in this species was several magnitudes higher than in other species and the bacteria were shown to display massive decreases in population size, in contrast to patterns of proliferation found in other host species. Diet strongly modified host survival after infection, with those on the high fat/low protein diet showing 30% survival at 8 days, versus almost 0% survival on the low fat/high protein diet. However, this was independent of bacterial load or variation in PO, providing evidence for diet‐mediated tolerance mechanisms rather than immune‐driven resistance.5.Evolutionary ecology has long focussed on immune resistance when investigating how organisms avoid succumbing to infection. Tolerance of infection has recently become a much more prominent concept and is suggested to be influential in disease dynamics. This is one of the first studies to find diet‐mediated tolerance.This article is protected by copyright. All rights reserved.
      PubDate: 2017-11-01T08:45:27.078192-05:
      DOI: 10.1111/1365-2656.12763
  • REVIEW: Dynamic, spatial models of parasite transmission in wildlife:
           their structure, applications, and remaining challenges
    • Authors: Lauren A. White; James D. Forester, Meggan E. Craft
      Abstract: 1.Individual differences in contact rate can arise from host, group, and landscape heterogeneity and can result in different patterns of spatial spread for diseases in wildlife populations with concomitant implications for disease control in wildlife of conservation concern, livestock, and humans. While dynamic disease models can provide a better understanding of the drivers of spatial spread, the effects of landscape heterogeneity have only been modelled in a few well‐studied wildlife systems such as rabies and bovine tuberculosis. Such spatial models tend to be either purely theoretical with intrinsic limiting assumptions or individual‐based models that are often highly species and system specific, limiting the breadth of their utility.2.Our goal was to review studies that have utilized dynamic, spatial models to answer questions about pathogen transmission in wildlife and identify key gaps in the literature. We begin by providing an overview of the main types of dynamic, spatial models (e.g., metapopulation, network, lattice, cellular automata, individual‐based, and continuous‐space) and their relation to each other. We investigate different types of ecological questions that these models have been used to explore: pathogen invasion dynamics and range expansion, spatial heterogeneity and pathogen persistence, the implications of management and intervention strategies, and the role of evolution in host‐pathogen dynamics.3.We reviewed 168 studies that consider pathogen transmission in free‐ranging wildlife and classify them by the model type employed, the focal host‐pathogen system, and their overall research themes and motivation. We observed a significant focus on mammalian hosts, a few well‐studied or purely theoretical pathogen systems, and a lack of studies occurring at the wildlife‐public health or wildlife‐livestock interfaces.4.Finally, we discuss challenges and future directions in the context of unprecedented human‐mediated environmental change. Spatial models may provide new insights into understanding, for example, how global warming and habitat disturbance contribute to disease maintenance and emergence. Moving forward, better integration of dynamic, spatial disease models with approaches from movement ecology, landscape genetics/genomics, and ecoimmunology may provide new avenues for investigation and aid in the control of zoonotic and emerging infectious diseases.This article is protected by copyright. All rights reserved.
      PubDate: 2017-10-22T18:00:25.797266-05:
      DOI: 10.1111/1365-2656.12761
  • Novel insights on population and range edge dynamics using an unparalleled
           spatiotemporal record of species invasion
    • Authors: Kristine L. Grayson; Derek M. Johnson
      Abstract: Quantifying the complex spatial dynamics taking place at range edges is critical for understanding future distributions of species, yet very few systems have sufficient data or the spatial resolution to empirically test these dynamics. This paper reviews how data from a large‐scale pest management program have provided important contributions to the fields of population dynamics and invasion biology.The invasion of gypsy moth (Lymantria dispar) is well‐documented from its introduction near Boston, Massachusetts USA in 1869 to its current extent of over 900,000 km2 in Eastern North America. Over the past two decades, the USDA Forest Service Slow the Spread (STS) program for managing the future spread of gypsy moth has produced unrivaled spatiotemporal data across the invasion front.The STS program annually deploys a grid of 60,000 – 100,000 pheromone‐baited traps, currently extending from Minnesota to North Carolina. The data from this program has provided the foundation for investigations of complex population dynamics and the ability to examine ecological hypotheses previously untestable outside of theoretical venues, particularly regarding invasive spread and Allee effects.This system provides empirical data on the importance of long‐distance dispersal and time lags on population establishment and spatial spread. Studies showing high rates of spatiotemporal variation of the range edge, from rapid spread to border stasis and even retraction, highlight future opportunities to test mechanisms that influence both invasive and native species ranges.The STS trap data have also created a unique opportunity to study low‐density population dynamics and quantify Allee effects with empirical data. Notable contributions include evidence for spatiotemporal variation in Allee effects, demonstrating empirical links between Allee effects and spatial spread, and testing mechanisms of population persistence and growth rates at range edges.There remain several outstanding questions in spatial ecology and population biology that can be tested within this system, such as the scaling of local ecological processes to large‐scale dynamics across landscapes. The gypsy moth is an ideal model of how important ecological questions can be answered by thinking more broadly about monitoring data.This article is protected by copyright. All rights reserved.
      PubDate: 2017-10-17T05:07:00.578779-05:
      DOI: 10.1111/1365-2656.12755
  • Parasite metacommunities: Evaluating the roles of host community
           composition and environmental gradients in structuring symbiont
           communities within amphibians
    • Authors: Joseph R. Mihaljevic; Bethany J. Hoye, Pieter T. J. Johnson
      Abstract: 1.Ecologists increasingly report the structures of metacommunities for free-living species, yet far less is known about the composition of symbiont communities through space and time. Understanding the drivers of symbiont community patterns has implications ranging from emerging infectious disease to managing host microbiomes.2.Using symbiont communities from amphibian hosts sampled from wetlands of California, USA, we quantified the effects of spatial, habitat filtering, and host community components on symbiont occupancy and overall metacommunity structure.3.We built upon a statistical method to describe metacommunity structure that accounts for imperfect detection in survey data – detection error-corrected elements of metacommunity structure (DECEMS) – by adding an analysis to identify covariates of community turnover. We applied our model to a metacommunity of 8 parasite taxa observed in 3571 Pacific chorus frogs (Pseudacris regilla) surveyed from 174 wetlands over 5 years.4.Symbiont metacommunity structure varied across years, showing nested structure in three years and random structure in two years. Species turnover was most consistently influenced by spatial and host community components. Occupancy generally increased in more southeastern wetlands, and snail (intermediate-host) community composition had strong effects on most symbiont taxa.5.We have used sophisticated but accessible statistical methods to reveal that spatial components - which influence colonization - and host community composition - which mediates transmission - both drive symbiont community composition in this system. These methods allow us to associate broad patterns of community turnover to local, species-level effects, ultimately improving our understanding of spatial community dynamics.This article is protected by copyright. All rights reserved.
      PubDate: 2017-10-04T06:05:53.155032-05:
      DOI: 10.1111/1365-2656.12735
  • The index case is not enough: Variation among individuals, groups, and
           social networks modify bacterial transmission dynamics
    • Authors: Carl N. Keiser; Noa Pinter-Wollman, Michael J. Ziemba, Krishna S. Kothamasu, Jonathan N. Pruitt
      Abstract: 1.The traits of the index case of an infectious disease outbreak, and the circumstances for their etiology, potentially influence the trajectory of transmission dynamics. However, these dynamics likely also depend on the traits of the individuals with whom the index case interacts.2.We used the social spider Stegodyphus dumicola to test how the traits of the index case, group phenotypic composition, and group size interact to facilitate the transmission of a GFP-labeled cuticular bacterium. We also compared bacterial transmission across experimentally generated “daisy-chain” versus “star” networks of social interactions. Finally, we compared social network structure across groups of different sizes.3.Groups of 10 spiders experienced more bacterial transmission events compared to groups of 30 spiders, regardless of groups’ behavioral composition. Groups containing only one bold spider experienced the lowest levels of bacterial transmission regardless of group size. We found no evidence for the traits of the index case influencing any transmission dynamics. In a second experiment, bacteria were transmitted to more individuals in experimentally induced star networks than in daisy-chains, on which transmission never exceeded three steps. In both experimental network types, transmission success depended jointly on the behavioral traits of the interacting individuals, however, the behavioral traits of the index case were only important for transmission on star networks.4.Larger social groups exhibited lower interaction density (i.e. had a low ratio of observed to possible connections) and were more modular, i.e., they had more connections between nodes within a sub-group and fewer connections across sub-groups. Thus, larger groups may restrict transmission by forming fewer interactions and by isolating sub-groups that interacted with the index case.5.These findings suggest that accounting for the traits of single exposed hosts has less power in predicting transmission dynamics compared to the larger-scale factors of the social groups in which they reside. Factors like group size and phenotypic composition appear to alter social interaction patterns, which leads to differential transmission of microbes.This article is protected by copyright. All rights reserved.
      PubDate: 2017-09-04T05:22:22.511102-05:
      DOI: 10.1111/1365-2656.12729
  • Strategies for managing rival bacterial communities: lessons from burying
    • Authors: Ana Duarte; Martin Welch, Chris Swannack, Josef Wagner, Rebecca M. Kilner
      Abstract: 1.The role of bacteria in animal development, ecology and evolution is increasingly well-understood, yet little is known of how animal behaviour affects bacterial communities. Animals that benefit from defending a key resource from microbial competitors are likely to evolve behaviours to control or manipulate the animal's associated external microbiota.2.We describe four possible mechanisms by which animals could gain a competitive edge by disrupting a rival bacterial community: ‘weeding’, ‘seeding’, ‘replanting’ and ‘preserving’. By combining detailed behavioural observations with molecular and bioinformatic analyses, we then test which of these mechanisms best explains how burying beetles, Nicrophorus vespilloides, manipulate the bacterial communities on their carcass breeding resource.3.Burying beetles are a suitable species to study how animals manage external microbiota because reproduction revolves around a small vertebrate carcass. Parents shave a carcass and apply antimicrobial exudates on its surface, shaping it into an edible nest for their offspring. We compared bacterial communities in mice carcasses that were either fresh, prepared by beetles or unprepared but buried underground for the same length of time. We also analysed bacterial communities in the burying beetle's gut, during and after breeding, to understand whether beetles could be ‘seeding’ the carcass with particular microbes.4.We show that burying beetles do not ‘preserve’ the carcass by reducing bacterial load, as is commonly supposed. Instead, our results suggest they ‘seed’ the carcass with bacterial groups which are part of the Nicrophorus core microbiome. They may also ‘replant’ other bacteria from the carcass gut onto the surface of their carrion nest. Both these processes may lead to the observed increase in bacterial load on the carcass surface in the presence of beetles. Beetles may also ‘weed’ the bacterial community by eliminating some groups of bacteria on the carcass, perhaps through the production of antimicrobials themselves.5.Whether these alterations to the bacterial community are adaptive from the beetle's perspective, or are simply a by-product of the way in which the beetles prepare the carcass for reproduction, remains to be determined in future work. In general, our work suggests that animals might use more sophisticated techniques for attacking and disrupting rival microbial communities than is currently appreciated.This article is protected by copyright. All rights reserved.
      PubDate: 2017-08-21T07:31:24.291935-05:
      DOI: 10.1111/1365-2656.12725
  • Effects of host species and environment on the skin microbiome of
           Plethodontid salamanders
    • Authors: Carly R. Muletz Wolz; Stephanie A. Yarwood, Evan H. Campbell Grant, Robert C. Fleischer, Karen R. Lips
      Abstract: 1.The amphibian skin microbiome is recognized for its role in defense against pathogens, including the deadly fungal pathogen Batrachochytrium dendrobatidis (Bd). Yet, we have little understanding of evolutionary and ecological processes that structure these communities, especially for salamanders and closely related species. We investigated patterns in the distribution of bacterial communities on Plethodon salamander skin across host species and environments.2.Quantifying salamander skin microbiome structure contributes to our understanding of how host-associated bacteria are distributed across the landscape, among host species, and their putative relationship with disease.3.We characterized skin microbiome structure (alpha-diversity, beta-diversity and bacterial operational taxonomic unit [OTU] abundances) using 16S rRNA gene sequencing for co-occurring Plethodon salamander species (35 P. cinereus, 17 P. glutinosus, 10 P. cylindraceus) at three localities to differentiate the effects of host species from environmental factors on the microbiome. We sampled the microbiome of P. cinereus along an elevational gradient (n = 50, 700 – 1000 masl) at one locality to determine whether elevation predicts microbiome structure. Finally, we quantified prevalence and abundance of putatively anti-Bd bacteria to determine if Bd-inhibitory bacteria are dominant microbiome members.4.Co-occurring salamanders had similar microbiome structure, but among sites salamanders had dissimilar microbiome structure for beta-diversity and abundance of 28 bacterial OTUs. We found that alpha-diversity increased with elevation, beta-diversity and the abundance of 17 bacterial OTUs changed with elevation (16 OTUs decreasing, 1 OTU increasing). We detected 11 putatively anti-Bd bacterial OTUs that were present on 90% of salamanders and made up an average relative abundance of 83% (SD ± 8.5) per salamander. All salamanders tested negative for Bd.5.We conclude that environment is more influential in shaping skin microbiome structure than host differences for these congeneric species, and suggest that environmental characteristics that co-vary with elevation influence microbiome structure. High prevalence and abundance of anti-Bd bacteria may contribute to low Bd levels in these populations of Plethodon salamanders.This article is protected by copyright. All rights reserved.
      PubDate: 2017-08-21T07:30:28.22075-05:0
      DOI: 10.1111/1365-2656.12726
  • The microbiota of diapause: how host-microbe associations are formed after
           dormancy in an aquatic crustacean
    • Authors: Alexandra A. Mushegian; Jean-Claude Walser, Karen E. Sullam, Dieter Ebert
      Abstract: 1.A critical question in symbiosis research is where and how organisms obtain beneficial microbial symbionts in different ecological contexts. Microbiota of juveniles are often derived directly from their mother or from the immediate environment. The origin of beneficial symbionts, however, is less obvious in organisms with diapause and dispersal stages, such as plants with dormant seeds and animals in ephemeral or strongly seasonal habitats. In these cases, parents and offspring are separated in time and space, which may affect opportunities for both vertical and horizontal transmission of symbionts.2.The planktonic crustacean Daphnia produces long-lasting resting eggs to endure winter freezing and summer droughts and requires microbiota for growth and reproduction. It is unknown how hatchlings from resting stages form associations with microbial consorts after diapause.3.Using natural samples of D. magna resting eggs after several years of storage, we show that the total bacterial community derived from both the exterior and interior of the eggs’ ephippial cases is sufficiently beneficial to ensure normal Daphnia functioning in otherwise bacteria-free conditions. We do not find direct evidence that the required bacteria are of maternal origin, though sequencing reveals that the resting stage is accompanied by bacterial taxa previously found in association with adult animals.4.These findings suggest that while Daphnia are strongly dependent on environmental bacteria for normal functioning, host-bacteria associations are somewhat general and availability of specific bacteria is not a strong constraint on host ecology. Nevertheless, animals and microbes may be ecologically linked through co-dispersal.This article is protected by copyright. All rights reserved.
      PubDate: 2017-07-17T05:00:42.970575-05:
      DOI: 10.1111/1365-2656.12709
  • Parasite-microbiota interactions potentially affect intestinal communities
           in wild mammals
    • Authors: Tuomas Aivelo; Anna Norberg
      Abstract: 1.Detecting interaction between species is notoriously difficult, and disentangling species associations in host-related gut communities is especially challenging. Nevertheless, due to contemporary methods, including metabarcoding and 16S sequencing, collecting observational data on community composition has become easier and much more common.2.We studied the previously collected data sets of intestinal bacterial microbiota and parasite compositions within longitudinally followed mouse lemurs by analysing the potential interactions with diversity metrics and novel joint species distribution modelling.3.Both methods showed statistical association between certain parasite species and bacterial microbiota composition. Unicellular Eimeria sp. had an effect on diversity of gut microbiota. The cestode Hymenolepis diminuta had negative associations with several bacterial orders, whereas closely related species H. nana had positive associations with several bacterial orders.4.Our results reveal potential interactions between some, but not all, intestinal parasites and gut bacterial microbiota. Host variables contributed over half of the total variation explained with the model, and sex was the most important single host variable; especially with microbiota, there were sex-related differences in the community composition.5.This study shows how joint species distribution modelling can incorporate both within-host dynamics of several taxa and host characteristics to model potential interactions in intestinal community. These results provide new hypothesis for interactions between and among parasites and bacterial microbiota to be tested further with experimental studies.This article is protected by copyright. All rights reserved.
      PubDate: 2017-07-03T04:21:19.286627-05:
      DOI: 10.1111/1365-2656.12708
  • Consequences of symbiont co-infections for insect host phenotypes
    • Authors: Ailsa H. C. McLean; Benjamin J. Parker, Jan Hrček, James C. Kavanagh, Peter A. D. Wellham, H. Charles J. Godfray
      Abstract: 1.Most animals host communities of symbiotic bacteria. In insects, these symbionts may have particularly intimate interactions with their hosts: many are intracellular and can play important roles in host ecology and evolution, including protection against natural enemies.2.We investigated how interactions between different species or strains of endosymbiotic bacteria within an aphid host influence the outcome of symbiosis for both symbiont and host.3.We first asked whether different combinations of facultative symbiont species or strains can exist in stable co-infections. We then investigated whether the benefits that facultative bacteria confer on their hosts (protection against natural enemies) are enhanced, reduced or unaltered by the presence of a co-infecting symbiont. We asked this both for co-infecting symbionts that confer different phenotypes on their hosts (protection against fungal pathogens vs. parasitoid wasps) and symbionts with overlapping functions. Finally, we investigated the additional survival costs to aphids of carrying multiple infections of symbiont species or strains, and compared symbiont titres in double and single infections.4.We found that stable co-infections were possible between all of the combinations of facultative symbiont species (Regiella insecticola + Hamiltonella defensa, Regiella + Rickettsiella sp., Regiella + Spiroplasma sp.) and strains (Hamiltonella) that we studied. Where symbionts provided protection against different natural enemies, no alteration in protection was observed in the presence of co-infections. Where symbionts provided protection against the same natural enemy, the level of protection corresponded to the higher of the two symbionts present. In some instances, aphid hosts suffered additional survival costs when hosting double infections. In the case of Hamiltonella, however, infection with multiple strains of the same symbiont led to lower symbiont titres than single infections, and actually improved aphid survival.5.We conclude that the long-term maintenance of symbiont co-infections in aphids is likely to be determined primarily by costs of co-infections and in some instances by redundancy of symbiont benefits.This article is protected by copyright. All rights reserved.
      PubDate: 2017-07-03T04:20:23.102587-05:
      DOI: 10.1111/1365-2656.12705
  • Gut microbial communities of American pikas (Ochotona princeps): evidence
           for phylosymbiosis and adaptations to novel diets
    • Authors: Kevin D. Kohl; Johanna Varner, Jennifer L. Wilkening, M. Denise Dearing
      Abstract: 1.Gut microbial communities provide many physiological functions to their hosts, especially in herbivorous animals. We still lack an understanding of how these microbial communities are structured across hosts in nature, especially within a given host species. Studies on laboratory mice have demonstrated that host genetics can influence microbial community structure, but that diet can overwhelm these genetic effects.2.We aimed to test these ideas in a natural system, the American pika (Ochotona princeps). First, pikas are high elevation specialists with significant population structure across various mountain ranges in the USA, allowing us to investigate whether similarities in microbial communities match host genetic differences. Additionally, pikas are herbivorous, with some populations exhibiting remarkable dietary plasticity and consuming high levels of moss, which is exceptionally high in fiber and low in protein. This allows us to investigate adaptations to an herbivorous diet, as well as to the especially challenging diet of moss.3.Here, we inventoried the microbial communities of pika cecal pellets from various populations using 16S rRNA sequencing to investigate structuring of microbial communities across various populations with different natural diets.4.Microbial communities varied significantly across populations, and similarities in microbial community structure were congruent with genetic differences in host population structure, a pattern known as ‘phylosymbiosis’.5.Several microbial members (Ruminococcus, Prevotella, Oxalobacter, Coprococcus) were detected across all samples, and thus likely represent a ‘core microbiome’. These genera are known to perform a number of services for herbivorous hosts such as fiber fermentation and the degradation of plant defensive compounds, and thus are likely important for herbivory in pikas. Moreoever, populations of pikas that feed on moss harbored microbial communities highly enriched in Melainabacteria. This uncultivable candidate phylum has been proposed to ferment fiber for herbivores, and thus may contribute to the ability of some pika populations to consume high amounts of moss.6.These findings demonstrate that both host genetics and diet can influence the microbial communities of the American pika. These animals may be novel sources of fiber-degrading microbes. Last, we discuss the implications of population-specific microbial communities for conservation efforts in this species.This article is protected by copyright. All rights reserved.
      PubDate: 2017-06-26T03:33:10.956297-05:
      DOI: 10.1111/1365-2656.12692
  • Queen presence mediates the relationship between collective behavior and
           disease susceptibility in ant colonies
    • Authors: Carl N. Keiser; Svjetlana Vojvodic, Imani O. Butler, Elizabeth Sartain, Volker H. W. Rudolf, Julia B. Saltz
      Abstract: The success of social living can be explained, in part, by a group's ability to execute collective behaviors unachievable by solitary individuals. However, groups vary in their ability to execute these complex behaviors, often because they vary in their phenotypic composition. Group membership changes over time due to mortality or emigration, potentially leaving groups vulnerable to ecological challenges in times of flux. In some societies, the loss of important individuals (e.g., leaders, elites, queens) may have an especially detrimental effect on groups’ ability to deal with these challenges.Here, we test whether the removal of queens in colonies of the acorn ant Temnothorax curvispinosus alters their ability to execute important collective behaviors and survive outbreaks of a generalist entomopathogen.We employed a split-colony design where one half of a colony was maintained with its queen, while the other half was separated from the queen. We then tested these subcolonies’ performance in a series of collective behavior assays and finally exposed colonies to the entomopathogenic fungus Metarhizium robertsii by exposing two individuals from the colony and then sealing them back into the nest.We found that queenright subcolonies outperformed their queenless counterparts in nearly all collective behaviors. Queenless subcolonies were also more vulnerable to mortality from disease. However, queenless groups that displayed more interactions with brood experienced greater survivorship, a trend not present in queenright subcolonies. Queenless subcolonies that engage in more brood interactions may have had more resources available to cope with two physiological challenges (ovarian development after queen loss and immune activation after pathogen exposure).Our results indicate that queen presence can play an integral role in colony behavior, survivorship, and their relationship. They also suggest that interactions between workers and brood are integral to colonies survival. Overall, a social group's history of social reorganization may have strong consequences on their collective behaviors and their vulnerability to disease outbreaks.This article is protected by copyright. All rights reserved.
      PubDate: 2017-06-22T04:16:07.517986-05:
      DOI: 10.1111/1365-2656.12696
  • Multi-modal defenses in aphids offer redundant protection and increased
           costs likely impeding a protective mutualism
    • Authors: Adam J. Martinez; Matthew R. Doremus, Laura J. Kraft, Kyungsun L. Kim, Kerry M. Oliver
      Abstract: 1.The pea aphid, Acyrthosiphon pisum, maintains extreme variation in resistance to its most common parasitoid wasp enemy, Aphidius ervi, which is sourced from two known mechanisms: protective bacterial symbionts, most commonly Hamiltonella defensa, or endogenously encoded defenses. We have recently found that individual aphids may employ each defense individually, occasionally both defenses together, or neither.2.In field populations, Hamiltonella-infected aphids are found at low to moderate frequencies and while less is known about the frequency of resistant genotypes, they show up less often than susceptible genotypes in field collections. To better understand these patterns, we sought to compare the strengths and costs of both types of defense, individually and together, in order to elucidate the selective pressures that maintain multi-modal defense mechanisms or that may favor one over the other.3.We experimentally infected five aphid genotypes (two lowly and three highly resistant), each with two symbiont strains, Hamiltonella-APSE8 (moderate protection) and Hamiltonella-APSE3 (high protection). This resulted in three sublines per genotype: uninfected, +APSE8, and +APSE3. Each of the fifteen total sublines was first subjected to a parasitism assay to determine its resistance phenotype and in a second experiment a subset were chosen to compare fitness (fecundity and survivorship) in presence and absence of parasitism.4.In susceptible aphid genotypes, parasitized sublines infected with Hamiltonella generally showed increased protection with direct fitness benefits, but clear infection costs to fitness in the absence of parasitism. In resistant genotypes, Hamiltonella infection rarely conferred additional protection, often further reduced fecundity and survivorship when enemy challenged, and resulted in constitutive fitness costs in the absence of parasitism. We also identified strong aphid-genotype X symbiont-strain interactions, such that the best defensive strategy against parasitoids varied for each aphid genotype; one performed best with no protective symbionts, the others with particular strains of Hamiltonella.5.This surprising variability in outcomes helps explain why Hamiltonella infection frequencies are often intermediate and do not strongly track parasitism frequencies in field populations. We also find that variation in endogenous traits, such as resistance, among host genotypes may offer redundancy and generally limit the invasion potential of mutualistic microbes in insects.This article is protected by copyright. All rights reserved.
      PubDate: 2017-04-05T02:35:41.575759-05:
      DOI: 10.1111/1365-2656.12675
  • Immune priming specificity within and across generations reveals the range
           of pathogens affecting evolution of immunity in an insect
    • Authors: Julien Dhinaut; Manon Chogne, Yannick Moret
      Abstract: 1.Many organisms can improve their immune response as a function of their immunological experience or that of their parents. This phenomenon, called immune priming, has likely evolved from repetitive challenges by the same pathogens during the host lifetime or across generation.2.All pathogens may not expose host to the same probability of re-infection and immune priming is expected to evolve from pathogens exposing the host to the greatest probability of re-infection. Under this hypothesis, the priming response to these pathogens should be specifically more efficient and less costly than to others.3.We examined the specificity of immune priming within and across generations in the mealworm beetle, Tenebrio molitor, by comparing survival of individuals to infection with bacteria according to their own immunological experience or that of their mother with these bacteria.4.We found that insects primed with Gram-positive bacteria became highly protected against both Gram-positive and Gram-negative bacterial infections, mainly due to an induced persistent antibacterial response, which did not exist in insects primed with Gram-negative bacteria. Insects primed with Gram-positive bacteria also exhibited enhanced concentration of hemocytes, but their implication in acquired resistance was not conclusive because of the persistent antibacterial activity in the hemolymph. Offspring maternally primed with Gram-positive and Gram-negative bacteria exhibited similarly improved immunity, whatever the bacteria used for the infection. Such maternal protection was costly in the larval development of offspring, but this cost was lower for offspring maternally primed with Gram-positive bacteria.5.While T. molitor can develop some levels of primed response to Gram-negative bacteria, the priming response to Gram-positive bacteria was more efficient and less costly. We concluded that Gram-positive bacterial pathogens were of paramount importance in the evolution of immune priming in this insect species.This article is protected by copyright. All rights reserved.
      PubDate: 2017-02-27T05:00:22.430441-05:
      DOI: 10.1111/1365-2656.12661
  • Effects of an early‐life paraquat exposure on adult resistance to
           oxidative stress, plumage colour and sperm performance in a wild bird
    • Abstract: 1.Early‐life stressful conditions can shape individual phenotypes and ultimately influence fitness. Oxidative stress is a pervasive threat that affects many fitness‐related traits and can modulate life‐history trade‐offs. Yet, the extent to which exposure to oxidative stress during early life can have long‐lasting effects on key fitness‐related traits remains to be elucidated, particularly in natural populations of vertebrates.2.Using a wild population of great tits Parus major, we experimentally dosed 11 day‐old birds with paraquat, a pro‐oxidant molecule, aiming at increasing oxidative stress. One year later, we recaptured 39 of them as adult recruiting breeders and quantified effects of the paraquat exposure on their resistance to oxidative stress, carotenoid‐based plumage colouration and male sperm performance.3.Despite the absence of a short‐term effect of paraquat on oxidative stress measured two days later, the pre‐fledging exposure to paraquat induced a reduction in individual oxidative damage measured at adulthood. Paraquat‐dosed individuals also had brighter plumage, but no effect was observed on male sperm performance.4.For the first time in a natural population of vertebrates, we experimentally show that an early‐life acute exposure to a pro‐oxidant has long‐lasting effects on individual resistance to oxidative stress at adulthood. Our results are in line with the environmental matching and the hormesis hypotheses but may also reflect selective disappearance of individuals with lower resistance to oxidative stress.This article is protected by copyright. All rights reserved.
  • Nocturnal departure timing in songbirds facing distinct migratory
    • Abstract: 1.Most migratory songbirds travel between their breeding areas and wintering grounds through a series of nocturnal flights. The timing of their departures defines the potential flight duration and thus the distance covered during a migratory night. Yet, migratory songbirds show substantial variation in their nocturnal departure timing.2.With this study we aim to assess whether the respective challenges of the migration route, namely its distance and nature, help to explain this variation.3.At a stopover site, we caught Northern Wheatears (Oenanthe oenanthe) of two subspecies that differ in distance and nature of their onward migration route in spring, but not in autumn. We determined the start of their nocturnal migratory restlessness during short‐term captivity, and radio‐tracked their nocturnal departure timing after release in both migration seasons.4.Northern Wheatears started their nocturnal migratory restlessness earlier when facing a long remaining migration distance and an extended sea barrier in spring. Individual departure directions generally affected the nocturnal departure timing with early departures being directed towards the respective migratory destination. In spring, this pattern was predominantly found in birds carrying relatively large fuel stores, but was absent in lean birds. At the same time, birds facing a short remaining migration distance and no extended sea barrier strongly reacted to relatively large fuel stores by an early start of nocturnal migratory behavior (migratory restlessness and departure timing), whereas this reaction was not found in birds facing a long remaining migration distance and sea barrier.5.These results suggest that the basic diel schedule of birds’ migratory activity is adapted to the onward migration route. Further they suggest that birds adjust their behavioral response, i.e. start of nocturnal migratory behavior, to fuel stores in relation to their impending migratory challenges. This is a substantial step in understanding variation of nocturnal departure timing and its adjustments in migratory songbirds. Further, it emphasizes the importance of interpreting birds’ nocturnal migratory behavior in the respective ecological context.This article is protected by copyright. All rights reserved.
  • Effects of chronic anthropogenic disturbance and rainfall on the
           specialization of ant‐plant mutualistic networks in the Caatinga, a
           Brazilian dry forest
    • Abstract: 1.Anthropogenic disturbance and climate change might negatively affect the ecosystem services provided by mutualistic networks. However, the effects of such forces remain poorly characterized. They may be especially important in dry forests, which (1) experience chronic anthropogenic disturbances (CADs) as human populations exploit forest resources and (2) are predicted to face a 22% decline in rainfall under climate change.2.In this study, we investigated the separate and combined effects of CADs and rainfall levels on the specialization of mutualistic networks in the Caatinga, a seasonally dry tropical forest typical of northeastern Brazil. More specifically, we examined interactions between plants bearing extrafloral nectaries (EFNs) and ants. We analyzed whether differences in network specialization could arise from environmentally mediated variation in the species composition, namely via the replacement of specialist by generalist species.3.We characterized these ant‐plant networks in 15 plots (20 x 20 m) that varied in CAD intensity and mean annual rainfall. We quantified CAD intensity by calculating three indices related to the main sources of disturbance in the Caatinga: livestock grazing (LG), wood extraction (WE), and miscellaneous resource use (MU). We determined the degree of ant‐plant network specialization using four metrics: generality, vulnerability, interaction evenness, and H2′.4.Our results indicate that CADs differentially influenced network specialization: we observed positive, negative, and neutral responses along LG, MU, and WE gradients, respectively. The pattern was most pronounced with LG. Rainfall also shaped network specialization, markedly increasing it. While LG and rainfall were associated with changes in network species composition, this trend was not related to the degree of species specialization. This result suggests that shifts in network specialization might be related to changes in species behavior, not species composition.5.Our study highlights the vulnerability of such dry forest ant‐plant networks to climate change. Moreover, dry forests experience highly heterogeneous anthropogenic disturbances, creating a geographic mosaic of selective forces that may shape the coevolution of interactions between ants and EFN‐bearing plants.This article is protected by copyright. All rights reserved.
  • A global database and ‘state of the field’ review of research into
           ecosystem engineering by land animals
    • Abstract: 1.Ecosystem engineers have been widely studied for terrestrial systems, but global trends in research encompassing the range of taxa and functions have not previously been synthesised.2.We reviewed contemporary understanding of engineer fauna in terrestrial habitats and assessed the methods used to document patterns and processes, asking: 1.Which species act as ecosystem engineers and with whom do they interact' 2. What are the impacts of ecosystem engineers in terrestrial habitats and how are they distributed' 3. What are the primary methods used to examine engineer effects and how have these developed over time' We considered the strengths, weaknesses and gaps in knowledge related to each of these questions, and suggested a conceptual framework to delineate ‘significant impacts’ of engineering interactions for all terrestrial animals.3.We collected peer‐reviewed publications examining ecosystem engineer impacts and created a database of engineer species to assess experimental approaches and any additional covariates that influenced the magnitude of engineer impacts.4.One hundred and twenty‐two species from twenty‐eight orders were identified as ecosystem engineers, performing five ecological functions. Burrowing mammals were the most researched group (27%). Half of all studies occurred in dry/arid habitats. Mensurative studies comparing sites with and without engineers (80%) were more common than manipulative studies (20%). These provided a broad framework for predicting engineer impacts upon abundance and species diversity. However, the roles of confounding factors, processes driving these patterns, and the consequences of experimentally adjusting variables, such as engineer density, have been neglected. True spatial and temporal replication has also been limited, particularly for emerging studies of engineer reintroductions.5.Climate change and habitat modification will challenge the roles that engineers play in regulating ecosystems, and these will become important avenues for future research. We recommend future studies include simulation of engineer effects and experimental manipulation of engineer densities to determine the potential for ecological cascades through trophic and engineering pathways due to functional decline. We also recommend improving knowledge of long‐term engineering effects and replication of engineer reintroductions across landscapes to better understand how large‐scale ecological gradients alter the magnitude of engineering impacts.This article is protected by copyright. All rights reserved.
  • Ecological determinants of avian malaria infections: An integrative
           analysis at landscape, mosquito and vertebrate community levels
    • Abstract: Vector and host communities, as well as habitat characteristics, may have important but different impacts on the prevalence, richness and evenness of vector‐borne parasites.We investigated the relative importance of (1) the mosquito community composition, (2) the vertebrate community composition and (3) landscape characteristics on the prevalence, richness and evenness of avian Plasmodium. We hypothesized that parasite prevalence will be more affected by vector‐related parameters, while host parameters should be also important to explain Plasmodium richness and evenness.We sampled 2,588 wild house sparrows (Passer domesticus) and 340,829 mosquitoes, and we performed vertebrate censuses at 45 localities in the Southwest of Spain. These localities included urban, rural and natural landscapes that were characterized by several habitat variables.Twelve Plasmodium lineages were identified in house sparrows corresponding to three major clades. Variation partitioning showed that landscape characteristics explained the highest fraction of variation in all response variables (21.0%–44.8%). Plasmodium prevalence was in addition explained by vector‐related variables (5.4%) and its interaction with landscape (10.2%). Parasite richness and evenness were mostly explained by vertebrate community‐related variables.The structuring role of landscape characteristics in vector and host communities was a key factor in determining parasite prevalence, richness and evenness, although the role of each factor differed according to the parasite parameters studied. These results show that the biotic and abiotic contexts are important to explain the transmission dynamics of mosquito‐borne pathogens in the wild.Las comunidades de vectores y hospedadores, así como las características del hábitat pueden tener importantes efectos sobre la prevalencia, riqueza y diversidad de los parásitos transmitidos por vectores.Hemos investigado la importancia relativa de i) la composición de la comunidad de mosquitos, ii) la composición de la comunidad de vertebrados y iii) las características de uso del suelo sobre la prevalencia, riqueza y diversidad de los parásitos aviares del genero Plasmodium. Predecimos que la prevalencia de parásitos se verá más afectada por los parámetros relacionados con la comunidad de vectores, mientras que las variables relacionadas con los hospedadores deberían ser más explicativas de la riqueza y la diversidad de Plasmodium.Se capturaron 2588 gorriones comunes (Passer domesticus) y 340829 hembras de mosquito y se realizaron censos de vertebrados en 45 localidades en el suroeste de España. Estas localidades incluyeron hábitats urbanos, rurales y naturales que se caracterizaron por distintas variables de uso del suelo.Se identificaron 12 linajes de Plasmodium en los gorriones correspondientes a tres clados filogenéticos principales. La partición de la varianza mostró que las características de uso del suelo explicaron la mayor fracción de variación en todas las variables dependientes (21.0%–44.8%). La prevalencia de Plasmodium se explicó además por variables relacionadas con la comunidad de vectores (5.4%) y su interacción con el ambiente (10.2%). La riqueza y la diversidad de los parásitos se explicaron principalmente por variables relacionadas con la comunidad de vertebrados.El papel de las características de uso del suelo en las comunidades de vectores y hospedadores fue un factor clave para determinar la prevalencia, riqueza y diversidad de Plasmodium, aunque el papel de cada factor difirió según los parámetros estudiados. Estos resultados muestran que los contextos bióticos y abióticos son importantes para explicar la dinámica de transmisión de los patógenos transmitidos por mosquitos en la naturaleza.Vector, host community and habitat characteristics have important but different impacts on the prevalence, richness and evenness of vector‐borne parasites. However, the joint impact of these factors has been neglected. The authors’ results highlight the key role of biotic and abiotic variables in explaining the transmission dynamics of these pathogens.
  • Revisiting concepts of thermal physiology: predicting responses of mammals
           to climate change
    • Abstract: 1.The accuracy of predictive models (also known as mechanistic or causal models) of animal responses to climate change depends on properly incorporating the principles of heat transfer and thermoregulation into those models. Regrettably, proper incorporation of these principles is not always evident.2.We have revisited the relevant principles of thermal physiology and analyzed how they have been applied in predictive models of large mammals, which are particularly vulnerable, to climate change. We considered dry heat exchange, evaporative heat transfer, the thermoneutral zone and homeothermy, and we examined the roles of size and shape in the thermal physiology of large mammals.3.We report on the following misconceptions in influential predictive models: underestimation of the role of radiant heat transfer, misassignment of the role and misunderstanding of the sustainability of evaporative cooling, misinterpretation of the thermoneutral zone as a zone of thermal tolerance or as a zone of sustainable energetics, confusion of upper critical temperature and critical thermal maximum, overestimation of the metabolic energy cost of evaporative cooling, failure to appreciate that the current advantages of size and shape will become disadvantageous as climate change advances, misassumptions about skin temperature, and lastly, misconceptions about the relationship between body core temperature and its variability with body mass in large mammals.4.Not all misconceptions invalidate the models, but we believe that preventing inappropriate assumptions from propagating will improve model accuracy, especially as models progress beyond their current typically‐static format to include genetic and epigenetic adaptation that can result in phenotypic plasticity.This article is protected by copyright. All rights reserved.
  • Linking demographic processes and foraging ecology in wandering albatross
           ‐ conservation implications
    • Abstract: 1.Population dynamics and foraging ecology are two fields of the population ecology that are generally studied separately. Yet foraging determines allocation processes and therefore demography. Studies on Wandering albatrosses Diomedea exulans over the past 50 years have contributed to better understand the links between population dynamics and foraging ecology. This paper reviews how these two facets of population ecology have been combined to better understand ecological processes, but also have contributed fundamentally for the conservation of this long‐lived threatened species.2.Wandering albatross research has combined a 50 year long‐term study of marked individuals with two decades of tracking studies that have been initiated on this species, favoured by its large size and tameness.3.At all stages of their life history the body mass of individuals plays a central role in allocation processes, in particular in influencing adult and juvenile survival, decisions to recruit into the population or to invest into provisioning the offspring or into maintenance.4.Strong age‐related variations in demographic parameters are observed and are linked to age‐related differences in foraging distribution and efficiency. Marked sex specific differences in foraging distribution, foraging efficiency and changes in mass over life time are directly related to the strong sex specific investment in breeding and survival trajectories of the two sexes, with body mass playing a pivotal role especially in males.5.Long‐term study has allowed determining the sex specific and age specific demographic causes of population decline, and the tracking studies have been able to derive where and how these impacts occur, in particular the role of long line fisheries.This article is protected by copyright. All rights reserved.
  • Of poisons and parasites: the defensive role of tetrodotoxin against
           infections in newts
    • Abstract: 1.Classical research on animal toxicity has focused on the role of toxins in protection against predators, but recent studies suggest these same compounds can offer a powerful defense against parasites and infectious diseases.2.Newts in the genus Taricha are brightly colored and contain the potent neurotoxin, tetrodotoxin (TTX), which is hypothesized to have evolved as a defense against vertebrate predators such as garter snakes. However, newt populations often vary dramatically in toxicity, which is only partially explained by predation pressure.3.The primary aim of this study was to evaluate the relationships between TTX concentration and infection by parasites. By systematically assessing micro‐ and macroparasite infections among 345 adult newts (sympatric populations of Taricha granulosa and T. torosa), we detected 18 unique taxa of helminths, fungi, viruses, and protozoans.4.For both newt species, per‐host concentrations of TTX, which varied from undetectable to >60 μg cm−2 skin, negatively predicted overall parasite richness as well as the likelihood of infection by the chytrid fungus, Batrachochytrium dendrobatidis, and ranavirus. No such effect was found on infection load among infected hosts. Despite commonly occurring at the same wetlands, T. torosa supported higher parasite richness and average infection load than T. granulosa. Host body size and sex (females > males) tended to positively predict infection levels in both species. For hosts in which we quantified leukocyte profiles, total white blood cell count correlated positively with both parasite richness and total infection load.5.By coupling data on host toxicity and infection by a broad range of micro‐ and macroparasites, these results suggest that – alongside its effects on predators – tetrodotoxin may help protect newts against parasitic infections, highlighting the importance of integrative research on animal chemistry, immunological defenses, and natural enemy ecology.This article is protected by copyright. All rights reserved.
  • Erratum
  • Erratum
  • Spatiotemporal heterogeneity in prey abundance and vulnerability shapes
           the foraging tactics of an omnivore
    • Abstract: 1.Prey abundance and prey vulnerability vary across space and time, but we know little about how they mediate predator‐prey interactions and predator foraging tactics. To evaluate the interplay between prey abundance, prey vulnerability, and predator space use, we examined patterns of black bear (Ursus americanus) predation of caribou (Rangifer tarandus) neonates in Newfoundland, Canada using data from 317 collared individuals (9 bears, 34 adult female caribou, 274 caribou calves).2.During the caribou calving season, we predicted that landscape features would influence calf vulnerability to bear predation, and that bears would actively hunt calves by selecting areas associated with increased calf vulnerability. Further, we hypothesized that bears would dynamically adjust their foraging tactics in response to spatiotemporal changes in calf abundance and vulnerability (collectively, calf availability). Accordingly, we expected bears to actively hunt calves when they were most abundant and vulnerable, but switch to foraging on other resources as calf availability declined.3.As predicted, landscape heterogeneity influenced risk of mortality, and bears displayed the strongest selection for areas where they were most likely to kill calves, which suggested they were actively hunting caribou. Initially, the per‐capita rate at which bears killed calves followed a type‐I functional response, but as the calving season progressed and calf vulnerability declined, kill rates dissociated from calf abundance. In support of our hypothesis, bears adjusted their foraging tactics when they were less efficient at catching calves, highlighting the influence that predation phenology may have on predator space use. Contrary to our expectations, however, bears appeared to continue to hunt caribou as calf availability declined, but switched from a tactic of selecting areas of increased calf vulnerability to a tactic that maximized encounter rates with calves.4.Our results reveal that generalist predators can dynamically adjust their foraging tactics over short time scales in response to changing prey abundance and vulnerability. Further, they demonstrate the utility of integrating temporal dynamics of prey availability into investigations of predator‐prey interactions, and move towards a mechanistic understanding of the dynamic foraging tactics of a large omnivore.This article is protected by copyright. All rights reserved.
  • Under the weather' –The direct effects of climate warming on a
           threatened desert lizard are mediated by their activity phase and burrow
    • Abstract: 1.For ectotherms such as lizards, the importance of behavioral thermoregulation in avoiding thermal extremes is well established and is increasingly acknowledged in modern studies of climate warming and its impacts. Less appreciated and understood are the buffering roles of retreat sites and activity phase, in part because of logistical challenges of studying below‐ground activity. Burrowing and nocturnal activity are key behavioral adaptations that have enabled a diverse range of reptiles to survive extreme environmental temperatures within hot desert regions. Yet, the direct impact of recent global warming on activity potential has been hypothesised to have caused extinctions in desert lizards, including the Australian arid zone skink Liopholis kintorei.2.We test the relevance of this hypothesis through a detailed characterisation of the above‐ and below‐ground thermal and hydric microclimates available to, and used by, Liopholis kintorei.3.We integrate operative temperatures with observed body temperatures to construct daily activity budgets, including the inference of subterranean behavior. We then assess the likelihood that contemporary and future local extinctions in this species, and those of similar burrowing habits, could be explained by the direct effects of warming on its activity budget and exposure to thermal extremes.4.We found that Liopholis kintorei spent only 4% of its time active on the surface, primarily at dusk, and that overall potential surface activity will be increased, not restricted, with climate warming. The burrow system provides an exceptional buffer to current and future maximum extremes of temperature (≈ 40 °C reduction from potential surface temperatures), and desiccation (burrows near 100% humidity). Therefore any climate warming impacts on this species are likely to be indirect.5.Our findings reflect the general buffering capacity of underground microclimates, therefore our conclusions for Liopholis kintorei are more generally applicable to nocturnal and crepuscular ectotherms, and highlight the need to consider the buffering properties of retreat sites and activity phase when forecasting climate change impacts.This article is protected by copyright. All rights reserved.
  • Experimental evidence that density mediates negative frequency‐dependent
           selection on aggression
    • Abstract: 1.Aggression can be beneficial in competitive environments if aggressive individuals are more likely to access resources than non‐aggressive individuals. However, variation in aggressive behaviour persists within populations, suggesting that high levels of aggression might not always be favoured.2.The goal of this study was to experimentally assess the effects of population density and phenotypic frequency on selection on aggression in a competitive environment.3.We compared survival of two strains of Drosophila melanogaster that differ in aggression across three density treatments and five frequency treatments (single strain groups, equal numbers of each strain, and strains mixed at 3:1 and 1:3 ratios) during a period of limited resources.4.While there was no difference in survival across single‐strain treatments, survival was strongly density‐dependent, with declining survival as density increased. Furthermore, at medium and high densities, there was evidence of negative frequency‐dependent selection, where rare strains experienced greater survival than common strains. However, there was no evidence of negative frequency‐dependent selection at low density.5.Our results indicate that the benefits of aggression during periods of limited resources can depend on the interaction between the phenotypic composition of populations and population density, both of which are mechanisms that could maintain variation in aggressive behaviours within natural populations.This article is protected by copyright. All rights reserved.
  • Validating dispersal distances inferred from autoregressive occupancy
           models with genetic parentage assignments
    • Abstract: 1.Dispersal distances are commonly inferred from occupancy data but have rarely been validated. Estimating dispersal from occupancy data is further complicated by imperfect detection and the presence of unsurveyed patches.2.We compared dispersal distances inferred from seven years of occupancy data for 212 wetlands in a metapopulation of the secretive and threatened California black rail (Laterallus jamaicensis coturniculus) to distances between parent‐offspring dyads identified with 16 microsatellites.3.We used a novel autoregressive multi‐season occupancy model that accounted for both unsurveyed patches and imperfect detection to quantify patch isolation using buffer radius (BRM) and incidence function (IFM) connectivity measures at 15 scales (1–10, 15, 20, 25, and 30 km). Connectivity measures were then fit as colonization covariates in occupancy models to estimate a model‐averaged dispersal distance.4.As predicted, colonization was more strongly related to connectivity at small spatial scales (< 10 km). AIC weights were greatest at 7 km for BRM and at 4 km for IFM.5.Model‐averaged dispersal distances (BRM = 7.46 km; IFM = 5.48 km) showed good agreement with the mean (± SE) dispersal distance from 23 parent‐offspring dyads (5.58 ± 1.92 km), indicating reasonably accurate mean dispersal distances can be inferred from occupancy data when isolation strongly affects colonization.This article is protected by copyright. All rights reserved.
  • Competition‐driven niche segregation on a landscape scale: evidence for
           escaping from syntopy toward allotopy in two coexisting sibling passerine
    • Abstract: 1.The role of interspecific competition for generating patterns in species’ distribution is hotly debated and studies taking into account processes occurring at both large and small spatial scales are almost missing. Theoretically, competition between species with overlapping niches should result in divergence of their niches in sympatry to reduce the costs of competition. Many species show a mosaic distribution within sympatric zones, with the syntopic sites occupied by both species, and allotopic sites where only one species occurs. It is unclear whether such mosaics arise as a consequence of competition‐driven niche segregation or due to the decline of their abundances towards range edges driven by environmental gradients.2.If the interspecific competition matters, we should observe (i) a shift in habitat preferences of one or both species between syntopy and allotopy, and (ii) between allopatry and allotopy. Moreover, (iii) species should show greater divergence in their habitat preferences in allotopy than in allopatry where (iv) no differences in habitat preferences may occur. Finally, (v) shifts should be generally greater in the competitively subordinate species than in the dominant species.3.We used a unique dataset on abundance of two closely related passerine species, the Common Nightingale (Luscinia megarhynchos) and the Thrush Nightingale (Luscinia luscinia), collected across their syntopy, allotopy and allopatry. The predictions were tested within a generalized mixed‐effects modelling framework.4.After accounting for environmental gradients perpendicular to the species’ contact zone, we found a strong support for all but one prediction. Habitat preferences of both species shifted markedly between syntopy and allotopy, as well as between allopatry and allotopy. Whereas the species preferred the same habitats in allopatry, their preferences became strikingly different in allotopy where the abundance of the Common Nightingale increased towards dry and warm sites with low coverage of pastures, while the abundance of the Thrush Nightingale showed exactly opposite trends. Fifth prediction was not supported.5.Our results indicate that the competition between closely related species can result in considerable changes in habitat use across their geographic ranges accompanied with divergence in their habitat preferences in sympatry. Here the species “escape” from competition to allotopic sites covered by habitats avoided by the competitor. Therefore, we argue that the interspecific competition is an important driver of species’ distribution at both large and small spatial scales.This article is protected by copyright. All rights reserved.
  • Foraging responses of sheep to plant spatial micro‐patterns can cause
           diverse associational effects of focal plant at individual and population
    • Abstract: 1.Multiple‐scale foraging decisions by large herbivores can cause associational effects of focal plant individuals neighbored with different species. Spatial micro‐patterns between the focal plant and its neighboring species within patches can affect herbivore foraging selectivity at within‐ and between‐patch scale, which may consequently lead to associational plant effects occurring at both plant individual and population levels. However, these associational effects have not been explored together in the plant‐herbivore interaction studies.2.We aim to evaluate how plant spatial micro‐pattern within different quality patches mediate herbivore foraging selectivity, thereby affecting the associational effects of focal plant individuals and population.3.Using sheep as the model herbivore and a medium preferred species as the focal plant, we conducted a manipulative experiment by allowing sheep grazing freely among three different quality patches, each of which consisted of preferred, un‐preferred and focal plant species with different abundances forming spatially aggregated or dispersed micro‐patterns.4.Results showed that, compared with the aggregated plant micro‐pattern, dispersed plant micro‐patterns within different quality patches increased sheep within‐patch selectivity, and caused diverse associational effects of focal plant individuals. Focal plant individuals experienced neighbor contrast defense (i.e. got protection in the high quality patch) and associational defense (i.e. got protection in the low quality patch), respectively, when plants distributed dispersedly in the low and high quality patch. Focal plant individuals simultaneously experienced associational susceptibility (i.e. got damage in the high quality patch) and neighbor contrast susceptibility (i.e. got damage in the low quality patch) when plants distributed dispersedly in the medium quality patch. Furthermore, dispersed plant micro‐patterns reduced sheep foraging selectivity between patches, and led to a lower consumption of focal plant population compared with the aggregated plant micro‐pattern.5.Herbivores adopt different within‐ and between‐patch foraging decisions to maintain a high intake of the preferred species in response to various plant micro‐patterns, and consequently cause diverse associational effects of both focal plant individuals and population. These associational effects have important implications for understanding the species coexistence and plant community assembly in the grazing ecosystems.This article is protected by copyright. All rights reserved.
  • Related herbivore species show similar temporal dynamics
    • Abstract: 1.Within natural communities, different taxa display different dynamics in time. Why this is the case we do not fully know. This thwarts our ability to predict changes in community structure, which is important for both the conservation of rare species in natural communities and for the prediction of pest outbreaks in agriculture.2.Species sharing phylogeny, natural enemies and/or life history traits have been hypothesized to share similar temporal dynamics. We operationalized these concepts into testing whether feeding guild, voltinism, similarity in parasitoid community, and/or phylogenetic relatedness explained similarities in temporal dynamics among herbivorous community members.3.Focusing on two similar data sets from different geographical regions (Finland and Japan), we used asymmetric eigenvector maps as temporal variables to characterize species‐ and community‐level dynamics of specialist insect herbivores on oak (Quercus). We then assessed whether feeding guild, voltinism, similarity in parasitoid community, and/or phylogenetic relatedness explained similarities in temporal dynamics among taxa.4.Species‐specific temporal dynamics varied widely, ranging from directional decline or increase to more complex patterns. Phylogeny was a clear predictor of similarity in temporal dynamics at the Finnish site, whereas for the Japanese site, the data were uninformative regarding a phylogenetic imprint. Voltinism, feeding guild and parasitoid overlap explained little variation at either location. Despite the rapid temporal dynamics observed at the level of individual species, these changes did not translate into any consistent temporal changes at the community level in either Finland or Japan.5.Overall, our findings offer no direct support for the notion that species sharing natural enemies and/or life history traits would be characterised by similar temporal dynamics, but reveal a strong imprint of phylogenetic relatedness. As this phylogenetic signal cannot be attributed to guild, voltinism or parasitoids, it will likely derive from shared microhabitat, microclimate, anatomy, physiology or behaviour. This has important implications for predicting insect outbreaks and for informing insect conservation. We hope that future studies will assess the generality of our findings across plant‐feeding insect communities and beyond, and establish the more precise mechanism(s) underlying the phylogenetic imprint.This article is protected by copyright. All rights reserved.
  • Sexual Signal Loss: The Link between Behavior and Rapid Evolutionary
           Dynamics in a Field Cricket
    • Abstract: 1.Sexual signals may be acquired or lost over evolutionary time, and are tempered in their exaggeration by natural selection.2.In the Pacific field cricket, Teleogryllus oceanicus, a mutation (“flatwing”) causing loss of the sexual signal, the song, spread in < 20 generations in two of three Hawaiian islands where the crickets have been introduced. Flatwing (as well as some normal‐wing) males behave as satellites, moving towards and settling near calling males to intercept phonotactic females.3.From 2005‐2012, we surveyed crickets and their responses to conspecific song, noting the morph and number of males and females before and after experimental playbacks. The three Hawaiian islands consistently contained different proportions of flatwing crickets, ranging from about 90% of males on Kauai to 50% on Oahu to rare on the Big Island of Hawaii.4.Flatwing and normal‐wing males do not appear to differ in responsiveness to playback, a behavior that should influence the likelihood of a male encountering a phonotactic female. Instead, male and female crickets from populations in which little to no calling song is perceptible during development tended to seek out callers more readily than crickets that developed in noisier environments. Such increased phonotaxis makes females more likely to find either the caller to which they are responding or to encounter a flatwing (or normal male satellite) that has also been attracted to the song.5.Our evidence suggests that pre‐existing behavioral plasticity (manifest as flexible responses to social – particularly acoustic – information in the environment) is associated with the rapid spread of the flatwing trait. Different social environments select for differential success of flatwing or normal‐wing males, which in turn alters the social environment itself.This article is protected by copyright. All rights reserved.
  • Animal host–microbe interactions
  • Good Daphnia parents do not control the offspring microbiome
    • Abstract: In Focus: Mushegian, A. A., Walser, J. ‐C., Sullam, K. E., & Ebert, D. (2018). The microbiota of diapause: How host–microbe associations are formed after dormancy in an aquatic crustacean. Journal of Animal Ecology, 87, 400–413. animals are colonized by micro‐organisms, most of which are benign or beneficial. Where do these micro‐organisms come from' Theory predicts that micro‐organisms which are transmitted vertically from parent to offspring are especially likely to be beneficial to the host, while horizontally acquired micro‐organisms are opportunistic and more variable in their impact on host performance. In this issue, Mushegian et al. () investigate the source of bacteria that are required for the growth and development of Daphnia water fleas to reproductive adults. They find that, although vertically transmitted bacteria can occur in the capsule enclosing the Daphnia eggs, the micro‐organisms that promote Daphnia performance are associated with the external surface of the capsule and are of likely environmental origin. This mode of transmission may be adaptive for Daphnia because, linked to the longevity and capacity for long‐distance dispersal of these eggs, the environmental circumstances encountered by parent and offspring may be different; with the implication, the parental micro‐organisms may not be optimal for the offspring. This study demonstrates that, although some animals require symbioses with specific coevolved, vertically transmitted microbial symbionts, other animals have evolved dependence on taxonomically variable micro‐organisms of environmental origin.Experimental approaches to investigate the source of microorganisms required by Daphnia. The starting material for the experiments of Mushegian et al were resting eggs that were either deprived of microorganisms in different locations (Experiment 1) or rendered microbe‐free by surface‐sterilization and then administered different microbial treatments (Experiment 2). The ephippium photo was taken by Frida Ben‐Ami and Liron Goren, the Daphnia photo was taken by Dieter Ebert and the egg photo taken by Elham Sheikh‐Jabbari.
  • Density regulation in Northeast Atlantic fish populations: density
           dependence is stronger in recruitment than in somatic growth
    • Abstract: 1.Population regulation is a central concept in ecology, yet in many cases its presence and the underlying mechanisms are difficult to demonstrate. The current paradigm maintains that marine fish populations are predominantly regulated by density‐dependent recruitment.2.While it is known that density‐dependent somatic growth can be present too, its general importance is unknown and most practical applications neglect it. This study aimed to close this gap by for the first time quantifying and comparing density dependence in growth and recruitment over a large set of fish populations.3.We fitted density‐dependent models to time series data on population size, recruitment and age‐specific weight from commercially exploited fish populations in the Northeast Atlantic Ocean and the Baltic Sea. Data were standardised to enable a direct comparison within and among populations, and estimated parameters were used to quantify the impact of density regulation on population biomass.4.Statistically significant density dependence in recruitment was detected in a large proportion of populations (70%) whereas for density dependence in somatic growth the prevalence of density dependence depended heavily on the method (26% and 69%). Despite age‐dependent variability, the density dependence in recruitment was consistently stronger among age groups and between alternative approaches that use weight‐at‐age or weight increments to assess growth. Estimates of density‐dependent reduction of biomass underlined these results: 97% of populations with statistically significant parameters for growth and recruitment showed a larger impact of density‐dependent recruitment on population biomass.5.The results reaffirm the importance of density‐dependent recruitment in marine fishes, yet they also show that density dependence in somatic growth is not uncommon. Further, the results are important from an applied perspective because density dependence in somatic growth affects productivity and catch composition, and therefore the benefits of maintaining fish populations at specific densities.This article is protected by copyright. All rights reserved.
  • Hunger mediates apex predator's risk avoidance response in
           wildland‐urban interface
    • Abstract: 1.Conflicts between large mammalian predators and humans present a challenge to conservation efforts, as these events drive human attitudes and policies concerning predator species. Unfortunately, generalities portrayed in many empirical carnivore landscape selection studies do not provide an explanation for a predator's occasional use of residential development preceding a carnivore‐human conflict event. In some cases, predators may perceive residential development as a risk‐reward tradeoff.2.We examine whether state dependent mortality‐risk sensitive foraging can explain an apex carnivore's (Puma concolor) occasional utilization of residential areas. We assess whether puma balance the risk and rewards in a system characterized by a gradient of housing densities ranging from wildland to suburban. Puma GPS location data, characterized as hunting and feeding locations, were used to assess landscape variables governing hunting success and hunting site selection. Hunting site selection behavior was then analyzed conditional on indicators of hunger state.3.Residential development provided a high energetic reward to puma, based on increases in prey availability and hunting success rates associated with increased housing density. Despite a higher energetic reward, hunting site selection analysis indicated that pumas generally avoided residential development, a landscape type attributed with higher puma mortality risk. However, when a puma experienced periods of extended hunger, risk avoidance behavior toward housing waned.4.This study demonstrates that an apex carnivore faces a tradeoff between acquiring energetic rewards and avoiding risks associated with human housing. Periods of hunger can help explain an apex predator's occasional use of developed landscapes and thus the rare conflicts in the wildland‐urban interface. Apex carnivore movement behaviors in relation to human conflicts are best understood as a three‐player community level interaction incorporating wild prey distribution.This article is protected by copyright. All rights reserved.
  • Invasion history alters the behavioural consequences of immune system
           activation in cane toads
    • Abstract: 1.Acute activation of the immune system often initiates a suite of behavioural changes. These ‘sickness behaviours’—involving lethargy and decreased activity—may be particularly costly on invasion fronts, where evolutionary pressures on dispersal favour individuals that move large distances.2.We used a combination of field and laboratory studies to compare sickness behaviours of cane toads from populations differing in invasion history. To do this we stimulated immune system activation by injecting lipopolysaccharide (LPS) to mimic bacterial infection.3.We predicted that LPS would result in less severe sickness behaviour in toads from invasion‐front populations because they had undergone selection for rapid and sustained dispersal (activities in conflict with lethargy and decreased activity).4.Contrary to our prediction, LPS injection caused a greater reduction in dispersal‐relevant traits in invasion‐front individuals than in conspecifics from the range core.5.Our data suggest that the rapid invasion of cane toads through tropical Australia has seen an evolutionary shift in the magnitude of sickness behaviour elicited by pathogen infection. The increased sickness behaviour among invasion‐front toads suggests a shift away from pathogen tolerance (seen in range‐core populations) towards resistance to pathogen attack. But as a consequence, when pathogens do become successfully established, toads from invasion‐front populations may have less capacity to tolerate their ill‐effects.This article is protected by copyright. All rights reserved.
  • Decreases in beetle body size linked to climate change and warming
    • Abstract: Body size is a fundamental ecological trait and is correlated with population dynamics, community structure and function, and ecosystem fluxes. Laboratory data from broad taxonomic groups suggest that a widespread response to a warming world may be an overall decrease in organism body size. However, given the myriad of biotic and abiotic factors that can also influence organism body size in the wild, it is unclear whether results from these laboratory assays hold in nature.Here we use datasets spanning 30 to 100 years to examine whether the body size of wild‐caught beetles has changed over time, whether body size changes are correlated with increased temperatures, and we frame these results using predictions derived from a quantitative review of laboratory responses of 22 beetle species to temperature.We found that 95% of laboratory‐reared beetles decreased in size with increased rearing temperature, with larger‐bodied species shrinking disproportionately more than smaller‐bodied beetles. In addition, the museum datasets revealed that larger‐bodied beetle species have decreased in size over time, that mean beetle body size explains much of the interspecific variation in beetle responses to temperature, and that long‐term beetle size changes are explained by increases in autumn temperature and decreases in spring temperature in this region.Our data demonstrate that the relationship between body size and temperature of wild‐caught beetles matches relatively well with results from laboratory studies, and that variation in this relationship is largely explained by interspecific variation in mean beetle body size.This long‐term beetle dataset is one of the most comprehensive arthropod body size datasets compiled to date, it improves predictions regarding the shrinking of organisms with global climate change, and together with the meta‐analysis data, call for new hypotheses to explain why larger‐bodied organisms may be more sensitive to temperature.The study uses long‐term collections of museum specimens to demonstrate that decreases in ground beetle body size over time are linked to increases in autumn temperatures. Field‐collected beetles have decreased in size at a faster rate than predicted by laboratory experiments.
  • Soil temperature effects on the structure and diversity of plant and
           invertebrate communities in a natural warming experiment
    • Abstract: 1.Global warming is predicted to significantly alter species physiology, biotic interactions, and thus ecosystem functioning, as a consequence of coexisting species exhibiting a wide range of thermal sensitivities. There is, however, a dearth of research examining warming impacts on natural communities.2.Here, we used a natural warming experiment in Iceland to investigate the changes in aboveground terrestrial plant and invertebrate communities along a soil temperature gradient (10–30 °C).3.The α‐diversity of plants and invertebrates decreased with increasing soil temperature, driven by decreasing plant species richness and increasing dominance of certain invertebrate species in warmer habitats. There was also greater species turnover in both plant and invertebrate communities with increasing pairwise temperature difference between sites. There was no effect of temperature on percentage cover of vegetation at the community level, driven by contrasting effects at the population level.4.There was a reduction in the mean body mass and an increase in the total abundance of the invertebrate community, resulting in no overall change in community biomass. There were contrasting effects of temperature on the population abundance of various invertebrate species, which could be explained by differential thermal tolerances and metabolic requirements, or may have been mediated by changes in plant community composition.5.Our study provides an important baseline from which the effect of changing environmental conditions on terrestrial communities can be tracked. It also contributes to our understanding of why community‐level studies of warming impacts are imperative if we are to disentangle the contrasting thermal responses of individual populations.This article is protected by copyright. All rights reserved.
  • Cuckoos host range is associated positively with distribution range and
           negatively with evolutionary uniqueness
    • Abstract: 1.The evolutionary distinctiveness (ED) score is a measure of phylogenetic isolation that quantifies the evolutionary uniqueness of a species.2.Here, we compared the ED score of parasitic and non‐parasitic cuckoo species worldwide, to understand whether parental care or parasitism represent the largest amount of phylogenetic uniqueness. Next, we focused only on 46 cuckoo species characterized by brood parasitism with a known number of host species, we explored the associations among ED score, number of host species and breeding range size for these species. We assessed these associations using phylogenetic generalized least squares (PGLS) models, taking into account the phylogenetic signal.3.Parasitic cuckoo species were not more unique in terms of evolutionary distinctiveness than non‐parasitic species. However, we found a significant negative association between the evolutionary uniqueness and host range, and a positive correlation between the number of host species and range size of parasitic cuckoos, probably suggesting a passive sampling of hosts by parasitic species as the breeding range broadens.4.The findings of this study showed that more generalist brood parasites occupied very different positions in a phylogenetic tree, suggesting that they have evolved independently within the Cuculiformes order. Finally, we demonstrated that specialist cuckoo species also represent the most evolutionarily unique species in the order of Cuculiformes.This article is protected by copyright. All rights reserved.
  • Socially informed dispersal in a territorial cooperative breeder
    • Abstract: 1.Dispersal is a key process governing the dynamics of socially and spatially structured populations, and involves three distinct stages: emigration, transience, and settlement. At each stage, individuals have to make movement decisions, which are influenced by social, environmental, and individual factors. Yet, a comprehensive understanding of the drivers that influence such decisions is still lacking, particularly for the transient stage during which free‐living individuals are inherently difficult to follow.2.Social circumstances such as the likelihood of encountering conspecifics can be expected to strongly affects decision making during dispersal, particularly in territorial species where encounters with resident conspecifics are antagonistic. Here we analyzed the movement trajectories of 47 dispersing coalitions of Kalahari meerkats (Suricata suricatta) through a landscape occupied by constantly monitored resident groups, while simultaneously taking into account environmental and individual characteristics.3.We used GPS locations collected on resident groups to create a geo‐referenced social landscape representing the likelihood of encountering resident groups. We used a step‐selection function to infer the effect of social, environmental and individual covariates on habitat selection during dispersal. Lastly, we created a temporal mismatch between the social landscape and the dispersal event of interest to identify the temporal scale at which dispersers perceive the social landscape.4.Including information about the social landscape considerably improved our representation of the dispersal trajectory, compared to analyses that only accounted for environmental variables. The latter were only marginally selected or avoided by dispersers. Before leaving their natal territory, dispersers selected areas frequently used by their natal group. In contrast, after leaving their natal territory, they selectively used areas where they were less likely to encounter unrelated groups. This pattern was particularly marked in larger dispersing coalitions and when unrelated males were part of the dispersing coalition.5.Our results suggest that, in socially and spatially structured species, dispersers gather and process social information during dispersal, and that reducing risk of aggression from unrelated resident groups outweighs benefits derived from conspecific attraction. Finally, our work underlines the intimate link between the social structure of a population and dispersal, which affect each other reciprocally.This article is protected by copyright. All rights reserved.
  • Current Spring Warming as a Driver of Selection on Reproductive Timing in
           a Wild Passerine
    • Abstract: 1.Evolutionary adaptation as a response to climate change is expected for fitness‐related traits affected by climate and exhibiting genetic variance. Although the relationship between warmer spring temperature and earlier timing of reproduction is well documented, quantifications and predictions of the impact of global warming on natural selection acting on phenology in wild populations remain rare. If global warming affects fitness in a similar way across individuals within a population, or if fitness consequences are independent of phenotypic variation in key‐adaptive traits, then no evolutionary response is expected for these traits.2.Here we quantified the selection pressures acting on laying date during a 24‐year monitoring of blue tits in southern Mediterranean France, a hot spot of climate warming. We explored the temporal fluctuation in annual selection gradients and we determined its temperature‐related drivers.3.We first investigated the month‐specific warming since 1970 in our study site and tested its influence on selection pressures using a model averaging approach. Then, we quantified the selection strength associated with temperature anomalies experienced by the blue tit population.4.We found that natural selection acting on laying date significantly fluctuated both in magnitude and in sign across years. After identifying a significant warming in spring and summer, we showed that warmer daily maximum temperatures in April were significantly associated with stronger selection pressures for reproductive timing. Our results indicated an increase in the strength of selection by 46% for every +1°C anomaly.5.Our results confirm the general assumption that recent climate change translates into strong selection favouring earlier breeders in passerine birds. Our findings also suggest that differences in fitness among individuals varying in their breeding phenology increase with climate warming. Such climate driven influence on the strength of directional selection acting on laying date could favour an adaptive response in this trait, since it is heritable.This article is protected by copyright. All rights reserved.
  • Corrigendum
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