The Journal Of Animal Ecology[JOURNAL]
Sun
200 papers
When temperature calls the shots: Pollinators' floral choices in a warming world.
Arroyo-Correa B
J Anim Ecol · 2025 Dec · PMID 41108560 · Publisher ↗
While biotic factors such as traits, abundance or community context have long been recognized as the main determinants of species interactions, abiotic conditions such as temperature can rewire these interactions even wh...
While biotic factors such as traits, abundance or community context have long been recognized as the main determinants of species interactions, abiotic conditions such as temperature can rewire these interactions even when species composition and abundance remain constant. Interaction establishment in plant-pollinator systems is particularly sensitive to these conditions, as pollinator metabolism, cognition and behaviour and floral reward production all respond strongly to thermal variation. Yet empirical evidence for community-wide consequences of such temperature-driven shifts in interactions remains limited. Arrowsmith et al. (2025) demonstrate that changes in temperature, independently of species turnover, can trigger pollinators' flexibility in floral resource use, reshaping which flowers they visit in natural diverse communities. These findings suggest that, alongside trait matching, abundance, phylogeny or spatiotemporal overlap, temperature plays a substantial and previously underappreciated role in shaping plant-pollinator interaction patterns. These thermal effects have particularly important implications at a broader scale as climate change accelerates, as temperature-driven interaction rewiring can cascade through interaction networks, influencing their emerging properties and functional outcomes. This study therefore underscores the need to incorporate the abiotic context into predictive models of these networks for anticipating how climate change may destabilize-or stabilize-ecological systems.
A field test of whether herbivores mitigate the effects of plant invasions on soil biodiversity.
Buchkowski RW
J Anim Ecol · 2026 Feb · PMID 41099184 · Publisher ↗
Research Highlight: Marco Fioratti Junod, Irene Cordero, Nadia Chinn, Jennifer Firn, Julia Holmes, Marcus Klein, Gabrielle Lebbink, Uffe N. Nielsen, Martin Schütz, Stephan Zimmermann, Anita C. Risch. (2025). Herbivory me...
Research Highlight: Marco Fioratti Junod, Irene Cordero, Nadia Chinn, Jennifer Firn, Julia Holmes, Marcus Klein, Gabrielle Lebbink, Uffe N. Nielsen, Martin Schütz, Stephan Zimmermann, Anita C. Risch. (2025). Herbivory mediates the response of below-ground food webs to invasive grasses. Journal of Animal Ecology. https://doi.org/10.1111/1365-2656.70113. A recent paper by Junod et al. (2025) tested whether herbivores could mitigate the effects of invasive African lovegrass on soil biodiversity in Australian grasslands. They found that herbivores, including livestock, native mammals and invertebrates, acted to reverse four of the 13 negative effects that African lovegrass had on soil biodiversity and function. Their work demonstrated two mechanisms through which herbivores may have acted-reducing plant litter and increasing soil temperature. The paper also highlights the difficulty of predicting the response of soil biodiversity to change because of unclear interdependencies among organisms. General techniques such as food web models, isotopic tracers and more detailed study of the lives of soil organisms will help us bridge this knowledge gap.
Deer migration, deer density, tick distribution and incidence of a tick-borne zoonosis.
Mysterud A, Rivrud IM, Meisingset EL … +2 more , Jore S, Viljugrein H
J Anim Ecol · 2025 Dec · PMID 41098021 · Publisher ↗
Our understanding of how migratory wildlife populations affect incidence of infectious diseases spilling over into humans is limited. Ticks are expanding their distribution towards northern latitudes, causing emergence o...
Our understanding of how migratory wildlife populations affect incidence of infectious diseases spilling over into humans is limited. Ticks are expanding their distribution towards northern latitudes, causing emergence of tick-borne diseases. Deer serve as reproduction hosts for adult ticks, supporting the tick populations. However, in northern areas, deer populations are partially migratory, and migrants occupy high elevation summer ranges that are unsuitable for ticks. Migration can thus theoretically lead to escape from exposure to ticks and to deer feeding fewer ticks, which lower disease hazard to humans. Combining data on Ixodes ricinus tick abundance with GPS-tracking data of red deer (Cervus elaphus), we quantified the distributional overlap of ticks and red deer along elevational gradients in Norway. Furthermore, we correlated both deer density and the proportion of migratory deer with the incidence of Lyme disease in humans. We found that migratory deer summer ranges had colder climate and overlapped less with tick distribution than those of resident deer. Deer density consistently increased Lyme disease incidence in humans. However, we found only weak evidence that deer migration negatively affected Lyme disease incidence. Our study provides a rare quantification of how host availability, in terms of both host density and migratory movement, affects risk of a zoonotic disease.
Harvest and natural predation shape selection for behavioural predictability in male wild turkeys.
Gulotta NA, Wightman PH, Collier BA … +1 more , Chamberlain MJ
J Anim Ecol · 2025 Dec · PMID 41090990 · Full text
Previous research has shown that traits increasing prey detectability, such as using open areas, higher activity levels and using areas frequented by hunters, reduce survival rates and are considered risk-taking behaviou...
Previous research has shown that traits increasing prey detectability, such as using open areas, higher activity levels and using areas frequented by hunters, reduce survival rates and are considered risk-taking behaviours. Despite extensive studies on how harvest-induced and natural selection impact average phenotypic expression, the influence of these factors on behaviour predictability remains unclear. Using a double hierarchical generalized linear modelling framework, we assessed variation in both average behavioural expression and predictability in male wild turkeys (n = 108) and explored how it related to susceptibility to harvest and predation. Our analysis revealed individual variation in predictability linked to risk-taking and activity (average speed-CVp = 0.28, 95% CrI = 0.23-0.33), with some males exhibiting more consistent behaviour than others. We also identified a behavioural type-predictability syndrome, where riskier individuals were more predictable, and more active individuals were less predictable (Average speed-r = 0.71, 95% CrI = 0.59-0.81). Additionally, individuals became more predictable and occurred closer to risky areas during the hunting season, coinciding with peak mortality for male wild turkeys. Our data suggest harvest-induced and natural selection on both behavioural types and behavioural predictability. Riskier behaviour types were more predictable in their behavioural expression and were more likely to be killed by both hunters and predators. We also found evidence that hunters selectively targeted individuals that were more active and unpredictable in their activity patterns, whereas predators preferentially targeted turkeys exhibiting less active, more predictable behaviours. Our findings suggest that adopting a cautious, sit-and-wait tactic may help male wild turkeys detect and avoid hunters, but may increase their vulnerability to predators that use a combination of visual and olfactory cues, along with area-restricted search behaviours, to locate prey. Our findings highlight the potential for harvest-induced selection to influence the behavioural composition of male wild turkeys, which has implications for management and conservation strategies.
Disentangling the influence of environmental conditions on sex determination in haplodiploid organisms.
Wittmann K, Klein AM, Pichler M … +1 more , Staab M
J Anim Ecol · 2025 Dec · PMID 41084912 · Full text
Sex determination is essential for the life history of sexually reproducing organisms. Understanding the mechanism behind sex determination decisions, however, is not trivial, as processes such as random meiosis can shap...
Sex determination is essential for the life history of sexually reproducing organisms. Understanding the mechanism behind sex determination decisions, however, is not trivial, as processes such as random meiosis can shape the sex of the offspring besides environmental conditions. Haplodiploid organisms are relatively unconstrained from these internal influences: Males develop from unfertilized and females from fertilized eggs. Females can thus base sex allocation on their individual parental expenditure and account for the prevalent environmental conditions they live in. We aim to disentangle the influence of environmental conditions on sex determination and resource allocation decisions of haplodiploid organisms (population sex ratio, individual sex allocation probability, individual resource allocation and foraging efficiency). For this, we studied the European orchard bee (Osmia cornuta) at a high spatial and temporal resolution in a quantitative field study. We applied a recently developed camera system and deep-learning-based evaluation toolset that allowed us to analyse over 1000 pollen collection flights (food provisioning for offspring) and over 800 clay collection flights (nest-building material) to test whether sex determination and resource allocation in haplodiploid organisms depend on environmental conditions. Contrary to expectations based on established sex determination theories, the overall population sex ratio and individual offspring resource allocation were independent of environmental conditions. Individual sex allocation probability, however, shifted with flower cover, connectivity of seminatural habitat, temperature and progressing season. Pollen and clay collection durations, proxies for foraging efficiency, were not influenced by available resources in the landscape. Instead, pollen collection efficiency decreased with higher temperatures and clay collection efficiency decreased with lower temperatures and progressing season (both represented by increasing flight durations). A short-term insurance strategy may explain the diverse influences of environmental conditions on individual sex allocation probability, whereas long-term bet-hedging might result in consistent offspring resource allocation and population sex ratio within a year, with potential carry-over effects into the next generation. We therefore conclude that sex determination is not monocausal and that nest-provisioning females might pursue multiple aims at the same time. We emphasize the importance of long-term data to further unravel the sex determination mechanisms of sexually reproducing organisms.
Stronger phylogenetic effects on birds than on plants, and on seed dispersal than on pollination mutualistic networks, in a subtropical evergreen broadleaf forest.
He X, Campos-Arceiz A, Lin L
J Anim Ecol · 2025 Dec · PMID 41081323 · Publisher ↗
Uncovering the underlying mechanisms that contribute to the structure of ecological networks is crucial and presents a significant challenge. It has been reported that phylogenetically related species tend to have simila...
Uncovering the underlying mechanisms that contribute to the structure of ecological networks is crucial and presents a significant challenge. It has been reported that phylogenetically related species tend to have similar characteristics within ecological networks, with the strength of the phylogenetic signal varying among interacting groups. However, the patterns of phylogenetic signal in different interacting groups (e.g. plants and birds) across various network types (e.g. seed dispersal and pollination) has yet to be thoroughly investigated. Furthermore, the question of whether phylogenetic specialists also exhibit high degree of interaction specialization in partner selection remains unresolved. We investigated the phylogenetic effect on the structure of annual and monthly plant-bird seed dispersal and pollination networks within a subtropical evergreen broadleaf forest in Ailao Mountains, southwest China. Our study focused on examining phylogenetic signals in species degree, as well as in taxonomic and phylogenetic composition of interacting partners for both birds and plants of these two types of mutualistic networks. Additionally, we explored the relationship between phylogenetic specialization and interaction specialization of each plant/bird species within networks. We found weak phylogenetic signal in species degree for both plants and birds in any of the networks. However, we found variations in the strength of phylogenetic signals that are associated with taxonomic and phylogenetic composition among different interacting groups. Closely related bird species exhibited a tendency to interact with partners that had similar taxonomic and phylogenetic composition, particularly for frugivorous birds. This pattern was not observed in either fruiting or flowering plants. In addition, phylogenetically specialized frugivorous bird species tend to also be interaction specialists. However, no such association was observed among birds within pollination networks or among plants in either type of networks. The phylogenetic effects of birds are stronger than those of plants in plant-bird mutualistic networks. This trend is particularly pronounced in the context of seed dispersal networks, as compared to those involving pollination. Our findings highlight the evolutionary fingerprint on the structure of plant-bird mutualistic networks, revealing varying phylogenetic effects across different interaction groups and network types within a subtropical evergreen broadleaf forest.
Carbon pathways and trophic attributes are conserved in carnivorous reef fishes across a major human disturbance gradient.
Ramirez MD, McMahon KW, Rooney N … +2 more , El-Sabaawi RW, Baum JK
J Anim Ecol · 2026 Jan · PMID 41077885 · Full text
Habitat degradation and overexploitation are key drivers of biodiversity loss globally. Negative, human-driven changes in habitat quality, species abundance, and community composition are well-documented across systems....
Habitat degradation and overexploitation are key drivers of biodiversity loss globally. Negative, human-driven changes in habitat quality, species abundance, and community composition are well-documented across systems. While it is understood that human stressors destabilize consumer-resource interactions, how energy pathways and food webs may reorganize in hyperdiverse tropical systems in response to human disturbance remains poorly understood due to their complexity and past methodological limitations. Leveraging recent advances in molecular isotope techniques, we performed an ecosystem-scale natural experiment to evaluate how human disturbance reorganizes carbon pathways and trophic structure in a hyperdiverse tropical system, Kiritimati Island, the world's largest atoll. We specifically employed novel integrations of bulk tissue and amino acid-specific stable isotope analyses applied to six nominally generalist fish species sampled across Kiritimati's well-documented human disturbance gradient. Sampled fish species comprised 48% of carnivorous reef fish biomass. Essential amino acid stable carbon isotope (δC) fingerprinting and Bayesian stable isotope mixing models indicated that the proportional contribution of the carbon sources supporting five of the six sampled fish species did not vary across the disturbance gradient. Energy disproportionately (>80%) originated from planktonic production and microbially reworked detritus for most species, with only minor contributions of carbon sourced from coral and epilithic algal matrices. Reef fish trophic ecology was also consistent across the atoll, with species maintaining isotopic niches (size and position) and trophic positions across the atoll despite significant human disturbance-mediated changes in community composition and habitat complexity. Our findings suggest that the energy channels connecting basal resources to upper trophic level generalist consumers can be highly conserved following significant human disturbance in hyperdiverse tropical systems. On coral atolls, specifically, robust planktonic or detrital energy channels may buffer nominally generalist carnivorous reef fishes from some negative effects of chronic local human disturbance, promoting the maintenance of dominant energy fluxes in disturbed habitats. These results illustrate that disturbance-mediated changes in ecosystem structure and function do not universally destabilize broad energy fluxes and trophic relationships in hyperdiverse ecosystems. On the contrary, there appear to be mechanisms that promote stability, such as broad reliance on system-dominant production sources.
Intraguild predation in sympatric seals and the effect on a declining population.
Langley I, Brownlow A, Russell DJF
J Anim Ecol · 2025 Dec · PMID 41077884 · Full text
Evidence of intraguild predation (IGP) is found across taxonomic groups but varies in its prevalence within predator populations. The effects of IGP can be similar to traditional predation, but when exploited by few, spe...
Evidence of intraguild predation (IGP) is found across taxonomic groups but varies in its prevalence within predator populations. The effects of IGP can be similar to traditional predation, but when exploited by few, specialist predators the impact on intraguild prey populations is less clear. Grey seals (Halichoerus grypus) and harbour seals (Phoca vitulina) are marine top predators with similar diets of a broad range of fish and cephalopods. However, in recent years, adult male grey seals have been observed predating both grey seals and harbour seals. Combining 11 years of strandings data and direct observations of predation from citizen-science across Scotland, we examined the prevalence, spatial extent and temporal trends of IGP by grey seals. These results informed realistic predation scenarios and the effect of IGP on a small, protected population of harbour seals was explored. IGP was geographically widespread, involving multiple, seemingly specialist adult males across distinct subpopulations. The prevalence of IGP, as revealed by strandings data, appeared to increase through the study. Predation was most pronounced on adult harbour seals during the breeding season, amplifying the population level impact of each predation event through the loss of future reproductive potential. Indeed, in a depleted population in southeast Scotland, the estimated peak predation level was projected to cause declines of 7%-11%, well within the rate of the current harbour seal decline. This study demonstrated the utility of integrating disparate datasets to address conservation challenges and highlights how IGP, while seemingly rare, can hold sympatric species in a predator pit and in small populations may contribute to declines.
Prey selection of a widespread carnivore relative to predator-prey co-occurrence in space and time.
Weiss KCB, Larson RN, Sterner B … +5 more , Wierzbowska I, VandeWoude S, Crooks K, Schipper J, Lewis JS
J Anim Ecol · 2025 Dec · PMID 41064946 · Publisher ↗
Understanding how prey selection relates to food availability and the environment is fundamental to conserving wildlife populations, especially in relation to anthropogenic factors. Most assessments of diet consider the...
Understanding how prey selection relates to food availability and the environment is fundamental to conserving wildlife populations, especially in relation to anthropogenic factors. Most assessments of diet consider the abundance of prey, but rarely temporal availability, prey biomass or the co-occurrence of species in space and time, all of which are particularly important in systems where predator and prey species are spatially ubiquitous. Using a novel method that combines camera trap and scat data, we assessed how the spatial distribution and/or activity of prey taxa influenced prey selection by bobcats (Lynx rufus), a widespread carnivore in urbanized (exurban and wildland-urban interface) and wildland areas of Colorado, USA. We developed prey availability estimates using asymmetric species interaction models (spatial) and activity overlap (temporal) analyses, then used a model selection framework to identify if co-occurrence (i.e. availability) between bobcats and prey species in space, time or both better predicted prey consumption. We further investigated whether different measures of prey consumption (i.e. the frequency of occurrence of prey items in scats vs. the proportion of biomass consumed) influenced the relationship between prey availability and use. Across study areas, bobcats consumed a variety of smaller mammals and birds, with cottontail rabbits appearing as the most important diet item. Our results indicated that incorporating time into availability estimates often better predicted prey consumption compared with spatial availability, particularly in wildland areas. Additionally, we found that both the frequency of occurrence of prey remains in scats and the proportion of biomass consumed had similar relationships to availability in our study system. Our results suggest that including temporal availability in analyses of prey consumption may be particularly informative in areas where prey species are spatially abundant. This study provides a framework for researchers and wildlife managers to consider temporal availability and species co-occurrence in studies evaluating prey selection by carnivores.
Estimating epidemiological parameters of highly pathogenic avian influenza in common terns using exact Bayesian inference.
Ewing DA, Bouwhuis S
J Anim Ecol · 2025 Dec · PMID 41063438 · Full text
Highly pathogenic avian influenza (HPAI) is a contagious viral disease that has led to the culling of huge amounts of poultry as well as the mortality of countless wild birds. The recent panzootic that began in 2021 has...
Highly pathogenic avian influenza (HPAI) is a contagious viral disease that has led to the culling of huge amounts of poultry as well as the mortality of countless wild birds. The recent panzootic that began in 2021 has been particularly notable for its devastating effect on seabird populations around the globe. Whilst transmission of HPAI within poultry has been relatively well studied, the recency of the current panzootic, combined with data collection challenges, means that much less is known about key epidemiological parameters, such as reproduction numbers, , of HPAI in wild populations. We develop methodology to carry out exact Bayesian parameter inference using reversible jump Markov chain Monte Carlo applied to mortality data in the form of daily carcass counts over the duration of subsequent outbreaks in a colony of common terns, Sterna hirundo, in 2022 and 2023. We estimate to be 3.7 (95% CI ) in 2022, and 3.2 (95% CI ) in 2023. The probability of mortality for an infected bird was estimated to drop from 0.26 (95% CI ) in 2022 to 0.14 (95% CI ) in 2023. Our findings furthermore suggest direct bird-to-bird transmission to be the predominant driver of infection within the colony, with environmental transmission playing a negligible role. We interpret our results to suggest that daily carcass removal may have kept environmental transmission at bay and that increased immunity and/or a change of the strain of HPAI may have caused the drop in mortality, but that facilitating 'social distancing', for example by providing more suitable breeding habitat, such that breeding densities can be reduced, will be key to reduce disease transmission in colony-breeding seabirds such as the terns.
Direct and indirect impacts of beaver ecosystem engineering have mixed effects on bats across feeding guilds.
Browning E
J Anim Ecol · 2025 Dec · PMID 41041816 · Publisher ↗
Research Highlight: Moser, V., Capitani, L., Zehnder, L., Hürbin, A., Obrist, M., Ecker, K., Boch, S., Minnig, S., Angst, C., Pomati, F., & Risch, A. (2025). Habitat heterogeneity and food availability in beaver-engineer...
Research Highlight: Moser, V., Capitani, L., Zehnder, L., Hürbin, A., Obrist, M., Ecker, K., Boch, S., Minnig, S., Angst, C., Pomati, F., & Risch, A. (2025). Habitat heterogeneity and food availability in beaver-engineered streams foster bat richness, activity and feeding. Journal of Animal Ecology. https://doi.org/10.1111/1365-2656.70136. Ecosystem engineers increase habitat heterogeneity, altering abiotic and biotic resources and are key to effective nature recovery. Reintroductions of Eurasian beavers (Castor fiber) in Europe have indirectly benefitted multiple taxonomic groups, aquatic and terrestrial, as their activities result in wetland restoration and diversification of vegetation composition and structure. Bats have been found to be positively impacted by beaver activity, yet the causal drivers were unknown. In a recent study, Moser et al. (2025) monitored bat species richness, activity and foraging activity at beaver pools and control beaver-free sites in Switzerland, finding significant increases in all three measures. Importantly, this study is the first to show significant positive impacts on bat foraging at beaver-engineered sites, and increases in species richness included red-listed species of conservation concern. By testing causal links of the impact of direct (increased canopy heterogeneity and standing deadwood density) and indirect (increased arthropod prey abundance) impacts of beaver engineering on bats, the authors found mixed responses at the foraging guild level. Edge-hunting aerial hawkers benefitted most from beaver engineering, and increased standing deadwood density was shown to have the strongest impact on bats. This study provides key evidence for the positive outcomes of beaver reintroductions on local biodiversity, highlighting the value of ecosystem engineers for nature recovery strategies.
Synching with seasonality: Predicting roe deer parturition phenology across its distributional range.
Kauffert J, Hewison AJM, Gehr B … +11 more , Hothorn T, Baur S, Gaillard JM, Kjellander P, König A, Müller J, Panzacchi M, Pellerin M, Tamasi B, Peters W, Menzel A
J Anim Ecol · 2025 Dec · PMID 41041808 · Full text
Latitude and elevation are the most commonly studied drivers of large-scale variation in the phenology of life-history events. However, these coarse gradients cannot reliably predict observed spatial variation in phenolo...
Latitude and elevation are the most commonly studied drivers of large-scale variation in the phenology of life-history events. However, these coarse gradients cannot reliably predict observed spatial variation in phenology. Although it is less often investigated, environmental predictability is also a selective force that constrains spatial variation in life-history events. Here, we explore how environmental predictability contributes to shaping spatial variation in the parturition phenology of roe deer across its distributional range in Europe. We compiled data on roe deer parturition dates across Europe within the research collaboration EURODEER, and from citizen scientists and related birth dates to elevation and environmental predictability, measured by Colwell's metrics of contingency and constancy, based on high-resolution climate and NDVI values. We predicted parturition timing and synchrony simultaneously within a single modelling framework using a distributional regression model (i.e. GAMLSS). Our approach provided more robust predictions of variation in birth phenology than commonly used approaches based on the combination of latitude and elevation. We found that roe deer align their parturition dates with both elevation and seasonality in environmental conditions. We also identified an apparent shift towards later parturition from west to east across the distributional range in Europe, putatively linked to relatively milder and more constant climates in the west. Contrary to our expectations, we did not find any consistent link between parturition synchrony and environmental predictability, suggesting that other factors, such as small-scale heterogeneities in landscape composition, play a key role. Our work emphasizes the importance of understanding macrophenological processes in the variation of life-history event timing across space. It also highlights the need to account for this spatial variation when investigating region-specific adaptations, particularly in light of climate change.
Resource suitability drives low use of avian-excavated tree cavities: A multi-state occupancy dynamics approach.
Zavala DJ, Cockle KL, Gomez MR … +4 more , Ferreyra CA, Bonaparte EB, Di Sallo FG, Ferraz G
J Anim Ecol · 2025 Nov · PMID 41035130 · Full text
Avian tree-cavity excavators are widely held to maintain diversity of forest vertebrate faunas through the facilitation of nesting resources, and yet in many systems they are absent or redundant. Why do avian excavators...
Avian tree-cavity excavators are widely held to maintain diversity of forest vertebrate faunas through the facilitation of nesting resources, and yet in many systems they are absent or redundant. Why do avian excavators sometimes supply only a small proportion of cavities used by non-excavating species? Researchers hypothesized that low re-use of excavated cavities could be driven by high rates of excavated cavity loss (low availability) or by low suitability of excavated cavities. The two hypotheses imply different cavity use dynamics. The availability hypothesis predicts high rates of excavated-cavity transition from excavators to secondary cavity-nesters. The suitability hypothesis predicts high transition rates from excavators to empty (unused), and high reuse rates for cavities previously used by secondary cavity-nesters. From 2006 to 2021, we studied 438 excavated and non-excavated bird nest cavities in the Atlantic Forest of Argentina, where excavators provide ~20% of cavities used by secondary cavity-nesters. We fit our data with a multi-state occupancy dynamics model that accounts for observation errors and estimates transition probabilities among cavity states 'Empty', 'Occupied by an excavator', 'Occupied by a secondary cavity-nester' and 'Lost'. We complemented the modelling results with a numerical simulation of cavity use dynamics. As predicted by the suitability hypothesis, the estimated probability of transition was high from excavator to empty (~0.75), low from excavator to secondary cavity-nester (~0.05) and high for reuse by secondary cavity-nester. Transition from 'Empty' to use by secondary cavity-nester was much more probable among non-excavated (~0.2) than excavated cavities (~0.05), which-our simulation shows-is compatible with secondary cavity-nesters using excavated cavities in proportion to their availability. Excavated cavities remained available for several years after their last use, suggesting suitability declines with age. We conclude that the marginal role of excavators as cavity producers is driven primarily by low suitability of their excavated cavities for other birds. Statistical support for the suitability hypothesis relied on the quantification of uncertainty about cavity states afforded by multi-state occupancy dynamics models. We encourage further exploration of state-transition probabilities among tree cavities and other multi-use resources to test ecological hypotheses and inform resource conservation policy.
Revealing species responses to environmental change through long-term data and mechanistic frameworks.
Zipkin EF, Williams PJ
J Anim Ecol · 2025 Nov · PMID 41017222 · Publisher ↗
Research Highlight: Dri, G. F., Bogdziewicz, M., Hunter, M., Witham, J., & Mortelliti, A. (2025). Coupled effects of forest growth and climate change on small mammal abundance and body weight: Results of a 39-year field...
Research Highlight: Dri, G. F., Bogdziewicz, M., Hunter, M., Witham, J., & Mortelliti, A. (2025). Coupled effects of forest growth and climate change on small mammal abundance and body weight: Results of a 39-year field study. Journal of Animal Ecology. https://doi.org/10.1111/1365-2656.70114. Biodiversity is declining due to global environmental change, yet it remains challenging to assess how specific drivers, such as climate change, affect the dynamics and trends of individual species. While many studies correlate climate variables with species abundance or occurrence, few explicitly link environmental drivers to demographic processes to uncover the mechanisms behind population trends. Such insight requires long-term data capable of revealing slow-moving, nonlinear trends and disentangling natural variability from directional change. In a 39-year study, Dri et al. (2025) demonstrate the power of sustained observation and mechanistic approaches by linking climate warming and forest maturation to increased acorn production, which enhanced body condition and survival in white-footed mice, ultimately driving population increases. Their findings underscore the importance of long-term data for identifying meaningful ecological trends and tracing the causal pathways by which biodiversity changes. Effective conservation under global change depends on two key shifts: greater investment in long-term biodiversity monitoring and broader adoption of frameworks that explicitly connect environmental drivers to demographic responses. Together, these approaches provide the foundation for adaptive, evidence-based conservation strategies in a rapidly changing world.
Microclimate refugia shape microclimatic niches and predict individual variability in post-breeding migration in a partially migratory species.
Ramos RF, Zalewska K, Gilroy JJ … +2 more , Silva JP, Franco AMA
J Anim Ecol · 2025 Dec · PMID 41017205 · Full text
The characterization of species' environmental niches can help predict biodiversity responses to global environmental change and identify areas where environmental suitability declines as the conditions change. However,...
The characterization of species' environmental niches can help predict biodiversity responses to global environmental change and identify areas where environmental suitability declines as the conditions change. However, environmental niches, that is the full range of conditions a species experiences, are frequently described at coarse spatial and temporal scales, thus are unlikely to capture the across-individual variability in exposure to microclimate conditions. Within species ranges and even within populations, individuals may vary in their ability to access microclimate refugia or may adopt different movement strategies to avoid exposure to unsuitable conditions. This individual variability currently remains unclear but could help us understand species' capacity to adjust to changes in climate. We used an 11-year satellite tracking dataset and high-resolution remotely sensed habitat and climate information to investigate the microclimatic niche of a partially migratory grassland bird, the endangered little bustard (Tetrax tetrax) in the species' western stronghold populations in Southern Europe. Our study, including both breeding and post-breeding seasons, aimed to determine whether the local conditions experienced by individuals during the breeding season can be used to predict individual movement strategies after breeding. Furthermore, we examined whether the distance travelled during post-breeding dispersive migration influenced the level of dissimilarity between seasonal niches experienced by individuals. The little bustard microclimatic niche was characterized along a gradient of temperature and microclimate refugia availability. Our results revealed that individuals occupying breeding areas with low microclimate refugia availability were more likely to move longer distances after breeding. Furthermore, long-distance migratory individuals maintained similar microclimatic niches across seasons, whereas short-distance migrants predominantly displayed a higher niche dissimilarity between seasons. Temperature and microclimate refugia availability during the breeding season can help predict individual differences in migratory behaviour of little bustards and their niche dissimilarity across seasons. Global warming and subsequent declines in microclimate refugia availability may force this species to move earlier and travel longer distances after breeding. This study provides information that can help design conservation strategies for little bustards and other endangered grassland bird species exposed to high temperatures.
Poison frog chemical defences are influenced by environmental availability and dietary selectivity for ants.
Martin NA, Rodríguez C, Alvarez-Buylla A … +9 more , Fiocca K, Morrison CR, Chamba-Carrillo A, García-Ruilova AB, Rentería J, Tapia EE, Coloma LA, Donoso DA, O'Connell LA
J Anim Ecol · 2025 Dec · PMID 40977130 · Publisher ↗
The ability to use small molecule alkaloids as defensive chemicals, often acquired via trophic interactions, has evolved in many organisms. Animals with diet-derived defences must balance food choices to maintain their d...
The ability to use small molecule alkaloids as defensive chemicals, often acquired via trophic interactions, has evolved in many organisms. Animals with diet-derived defences must balance food choices to maintain their defence reservoirs along with other physiological needs. Poison frogs accumulate skin alkaloids from their arthropod diet, but whether they show selectivity for specific prey remains unexplored. We investigated the role of leaf litter prey availability and dietary selectivity in shaping poison frog chemical defences along a geographic gradient. Specifically, we examined skin alkaloid composition, stomach contents and leaf litter ants in aposematic diablito frogs (Oophaga sylvatica) at five sites in north-western Ecuador and in sympatric, cryptic Chimbo rocket frogs (Hyloxalus infraguttatus) at one site. Our results show that differential availability of leaf litter ants influenced alkaloid profiles across diablito populations, and low levels of alkaloids were observed in the sympatric, 'undefended' Chimbo rocket frog. Ants were the primary dietary component of the defended species, while the 'undefended' species ate other prey categories including beetles and larvae in addition to ants. A prey selection analysis suggested that defended and 'undefended' frogs both feed on a high proportion of specific small ant genera that naturally contain alkaloids, suggesting that selectivity for toxic prey is not restricted to classically aposematic and highly toxic species. These findings suggest that poison frogs' use of feeding resources relative to availability may be an understudied and important selection factor in the evolution of acquired defences.
Complex effects of climatic variation on bumblebee queen fitness.
Archer CR, Schmid-Hempel P, Schmid-Hempel R … +1 more , Wilfert L
J Anim Ecol · 2025 Dec · PMID 40974058 · Full text
Climate change is a global biodiversity threat. To understand how a changing climate affects individual fitness and gain insights into which mechanisms are responsible, we need to establish how climatic variation affects...
Climate change is a global biodiversity threat. To understand how a changing climate affects individual fitness and gain insights into which mechanisms are responsible, we need to establish how climatic variation affects individual life-history traits (e.g. growth, survival and reproduction). Long-term data linking insect life histories and climate parameters are therefore valuable but, unfortunately, rare. Here, we test how climatic variation affects health, survival and reproduction in a key European pollinator, the buff-tailed bumblebee Bombus terrestris. We relate climatic variation experienced by developing queens in the field, caught between 2000 and 2014, to fitness traits assayed in these queens under otherwise constant lab conditions. We show that wet years consistently reduce queen fitness, while warm temperatures have positive and negative impacts. Behind these annual effects lies strong seasonality. In particular, climatic conditions experienced by young queens as they forage, mate and enter hibernation are vital determinants of whether they reproduce the following spring. Results suggest that climatic drivers that reduce queen resource acquisition prior to hibernation, or accelerate resource loss over winter, are especially detrimental to spring queen fitness. This suggests a strategy to mitigate the negative effects of climate change on bumblebees: ensuring high-quality forage late in summer before queens enter diapause.
Density dependent habitat selection in response to habitat loss in a coral reef fish.
Boström-Einarsson L, Bonin MC, Munday PL … +2 more , Jones GP, Keith SA
J Anim Ecol · 2025 Dec · PMID 40974053 · Full text
Habitat degradation alters the availability and quality of resources, with ramifications for how populations distribute across remnant patches. Decisions about habitat use are often made to optimise fitness by minimising...
Habitat degradation alters the availability and quality of resources, with ramifications for how populations distribute across remnant patches. Decisions about habitat use are often made to optimise fitness by minimising competition for resources. Individuals can sort themselves optimally across patches by selecting habitat based on the density of resident individuals, yet it is unclear whether this mechanism is disrupted by habitat loss. Moreover, density-dependent habitat selection could create a socially reinforced 'bandwagon' effect in species that use adults as a positive settlement cue. Here, we aimed to (1) determine the effect of habitat degradation on density-dependent habitat selection and (2) test whether habitat use by adults influences settlement decisions by juveniles via a bandwagon effect in the coral-associated reef fish, Pomacentrus moluccensis. We combined field surveys with a habitat choice experiment in Pomacentrus moluccensis to assess how fish respond to varying coral quality and conspecfici densities. Field observations revealed that adults only used dead coral on degraded reefs where fish densities on surrounding remnant live colonies were exceptionally high. When presented experimentally with the choice of two colonies, fish were more likely to choose a near empty alternate colony when the other colony was severely crowded with conspecifics. Taken together, these results offer strong support for density-dependent habitat selection during habitat loss. This choice cascades to influence juvenile habitat use: juveniles selected dead corals to a greater extent if there was a conspecific adult present. To our knowledge, this is the first empirical demonstration of how habitat degradation can trigger density-dependent habitat selection, which in turn may shape settlement decisions in the next generation via socially mediated cues.
Long-range pollen transport across the North Sea: Insights from migratory hoverflies landing on a remote oil rig.
Doyle TD, Jimenez-Guri E, Barnes JC … +5 more , Hannah C, Murray S, Wyatt CDR, Poole OM, Wotton KR
J Anim Ecol · 2025 Nov · PMID 40963187 · Full text
Insect pollinators play a crucial role in the reproductive success of many plant species, with their movement patterns important in shaping gene flow across plant populations. Movements vary greatly from central place fo...
Insect pollinators play a crucial role in the reproductive success of many plant species, with their movement patterns important in shaping gene flow across plant populations. Movements vary greatly from central place foragers that move over relatively short distances to migrants that move over very long distances. Of these highly mobile flower visitors, migratory hoverflies are of high ecological and economic importance as a large group of globally distributed pollinators, capable of connecting distant ecosystems through long-range seasonal movements. However, understanding their role in pollen transport during predominantly high-altitude migration remains challenging due to sampling constraints and the obscured identity of vectored pollen caused by post-migratory foraging from local resources. To address this, we employ ITS2 region metabarcoding to identify pollen species transported by migratory hoverflies during four distinct June or July migration events onto an oil rig devoid of vegetation and found 200 km off the coast of Scotland in the North Sea. Of 121 sampled marmalade hoverflies (Episyrphus balteatus), 92% carried pollen, with metabarcoding of 86 individuals indicating pollen from an average of up to eight plant species per individual (range: 1-14) and 102 species in total across all four events. Dominant pollen sources included common nettle (Urtica dioica), black elder (Sambucus nigra) and meadowsweet (Filipendula ulmaria) alongside visits to vegetable, legume, cereal, nut and fruit species. Backward wind trajectory analysis indicated northward migration in June, originating from the Netherlands, northern Germany and Denmark, over 500 km away. Conversely, migration in late July suggested southward movements from Norway, albeit with lower confidence. Forward trajectory analysis suggested potential destinations following departure from the oil rig including Norway or the Shetland Islands around 250 km away for the June migrations and Scotland for the July event. Our findings highlight the capacity of migratory hoverflies to transport diverse pollen species across extensive distances, underscoring their potential role in long-distance gene flow. Further research is essential to evaluate the ecological and agricultural implications of this phenomenon and its impact on plant communities.
Plasticity in a key life-history trait contributes to population cycles in an insect herbivore.
Barbour MA, St-Pierre F
J Anim Ecol · 2025 Oct · PMID 40960000 · Publisher ↗
Research Highlight: Myers, J. H., & Cory, J. S. (2025). Long-term population dynamics of western tent caterpillars: History, trends and causes of cycles. Journal of Animal Ecology. https://doi.org/10.1111/1365-2656.70104...
Research Highlight: Myers, J. H., & Cory, J. S. (2025). Long-term population dynamics of western tent caterpillars: History, trends and causes of cycles. Journal of Animal Ecology. https://doi.org/10.1111/1365-2656.70104. For centuries, population cycles have intrigued ecologists and posed challenges for resource managers. These dramatic fluctuations are influenced by strong interactions with natural enemies and/or the climate, yet these external drivers alone are typically insufficient to explain the observed cycles. Cyclic changes in life-history traits (e.g. fecundity) often play a significant role, though the mechanisms underlying these regular phenotypic shifts remain largely undetermined. Here Myers and Cory (2025) convincingly demonstrate the key role of plastic changes in fecundity in driving the 8-11-year population cycles of the western tent caterpillar Malacosoma californicum pluviale. These cycles are partially driven by lethal infections from a specialized baculovirus Malacosoma pluviale nucleopolyhedrovirus. Although tent caterpillars evolve increased resistance to the virus following peak infection periods, this resistance does not incur a fecundity cost, suggesting that eco-evolutionary feedback does not regulate this cycle. Instead, sublethal viral infections induce plastic reductions in fecundity. Declines in food quantity and quality following peak defoliation periods likely further contribute to these plastic changes. While climate variation does influence population growth, future climate change is unlikely to disrupt these cycles. Taken together, this long-term research underscores the importance of phenotypic plasticity in shaping dramatic herbivore population cycles. Future research on eco-evolutionary dynamics should consider, more even-handedly, alternative mechanisms by which the environment can feedback to cause phenotypic change.
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