The Journal Of Animal Ecology[JOURNAL]
Sun
200 papers
Repeated trends in altitudinal gradients of diversity: How habitat filtering and biotic interactions structure ecological communities.
Fougeray R, Roy A, Penager C … +8 more , Correa Pimpao G, Mori Pezo R, Charlet LP, Page N, Sculfort O, Gallusser S, Elias M, McClure M
J Anim Ecol · 2026 Apr · PMID 42041179 · Publisher ↗
Understanding how biodiversity is structured along tropical elevational gradients requires disentangling the relative roles of regional evolutionary history and local processes shaping ecological assemblies. Here, Ithomi...
Understanding how biodiversity is structured along tropical elevational gradients requires disentangling the relative roles of regional evolutionary history and local processes shaping ecological assemblies. Here, Ithomiini butterfly communities were studied along repeated elevational gradients in two Neotropical regions with contrasting evolutionary histories: the Amazonian Andes and the Guiana Shield. The study tested whether similar elevational patterns of taxonomic, mimetic and phylogenetic structure emerge despite distinct regional species pools, and whether abiotic and biotic factors contribute to shaping these patterns. Despite marked regional differences in overall richness, consistent elevational patterns emerged across both regions. Taxonomic and mimetic richness increased with elevation and were accompanied by stronger phylogenetic clustering, indicating that similar habitat filtering processes operate along altitudinal gradients irrespective of regional context. Phylogenetic β-diversity was predominantly driven by lineage turnover, particularly in the Andes, highlighting the role of elevational gradients in promoting replacement of phylogenetically distinct lineages rather than simple species loss. These shared patterns suggest that altitude has a strong and repeatable effect on community structure, with habitat filtering acting locally on regionally distinct species pools. Abiotic factors such as temperature appeared to constrain species distributions at broad spatial scales, whereas biotic interactions acted more locally. In particular, butterfly diversity was positively associated with potential host plant richness and predation pressure, indicating that ecological interactions can further shape local community composition once broad-scale environmental constraints are accounted for. By integrating phylogenetic structure, biotic interactions and environmental gradients across regions with contrasting evolutionary histories, this study shows how regional species pools and local ecological filtering jointly shape tropical biodiversity and highlights that similar elevational assembly processes could arise independently across the Neotropics.
Nesting biology shapes climate vulnerability of social bees (Bombus spp.).
Mullan FR, Green NS, Youngsteadt E … +2 more , McCluney KE, Penick CA
J Anim Ecol · 2026 Jul · PMID 42041164 · Publisher ↗
Climate warming is a major driver of global pollinator declines, including social bees that live in large colonies and provide critical pollination services. Nesting biology plays a key role in determining a colony's res...
Climate warming is a major driver of global pollinator declines, including social bees that live in large colonies and provide critical pollination services. Nesting biology plays a key role in determining a colony's resilience to climate change, but its influence on colony performance has received little attention. We investigate how climate warming affects bumble bee foraging efficiency and thermoregulatory behaviours under mid-century and late-century climate projections. We measured ambient air and nest temperatures in simulated above-ground and below-ground nests, assessed temperature dependence of foraging activity and conducted controlled trials to quantify worker thermoregulatory behaviours (wing fanning and brood incubation). Contrary to predictions, our results show that warming will increase optimal foraging hours for bumble bees and reduce brood incubation needs, potentially improving foraging performance. However, extreme summer temperatures could greatly increase fanning demands, particularly for above-ground nests, which would divert workers from foraging and other essential colony tasks. Our findings highlight that above-ground-nesting bumble bees are particularly vulnerable to warming due to escalating thermoregulatory demands, which could lead to colony failure under extreme conditions. Conservation efforts should consider nesting environment as a critical factor in climate resilience strategies for bees and other animal species.
Yellow fever virus outbreak caused declines in survival and modified dispersal of wild golden lion tamarins.
Klain V, Gogarten JF
J Anim Ecol · 2026 Jun · PMID 42026996 · Publisher ↗
Research Highlight: Ponchon, A., Choquet, R., Martins, A., Ruiz-Miranda, C., Albert, C., & Romano, V. (2026). Yellow fever outbreak temporarily changes dispersal patterns in an endangered primate. Journal of Animal Ecolo...
Research Highlight: Ponchon, A., Choquet, R., Martins, A., Ruiz-Miranda, C., Albert, C., & Romano, V. (2026). Yellow fever outbreak temporarily changes dispersal patterns in an endangered primate. Journal of Animal Ecology. https://doi.org/10.1111/1365-2656.70250. Infectious diseases can be drivers of wildlife population dynamics, but how they reshape host movement and social organization remains poorly understood. Ponchon et al. (2026) present one of the rare examples where the impact of a disease outbreak on survival can be measured across a population of wild mammals and subsequently linked to behavioural changes of these animals. They use a unique opportunity by tracking the survival and dispersal decisions of golden lion tamarins (Leontopithecus rosalia) during a sylvatic yellow fever outbreak. Using a 13-year capture-recapture dataset, the authors show that the outbreak caused a temporary decline in adult survival and triggered scale-dependent behavioural responses. While local dispersal within forest fragments decreased, the probability of long-distance dispersal across the matrix increased tenfold. At the same time, group sizes declined during the outbreak, while the number of social groups remained stable and increased after the outbreak. These results indicate that recovery did not involve a simple return to pre-outbreak conditions, but rather a reorganization of social structure characterized by smaller and more numerous groups. These findings highlight that, in vector-borne systems, movement may offer only limited protection against infection and demonstrate that disease outbreaks can lead to lasting population-wide changes in group sizes.
Parasites alter host community structure in a natural experiment.
Potter T, Mohammed RS, Goldberg JF … +3 more , Reznick DN, Travis J, Bassar RD
J Anim Ecol · 2026 Jun · PMID 42011692 · Publisher ↗
Parasites can profoundly alter host communities. However, the impact of parasites can vary from one community to another. Understanding why the impact of parasites varies across communities is challenging because it requ...
Parasites can profoundly alter host communities. However, the impact of parasites can vary from one community to another. Understanding why the impact of parasites varies across communities is challenging because it requires (i) separating the direct effects of the parasite on the host species from the indirect effects it exerts through the ecological interactions among the hosts and (ii) identifying how the presence of one host alters rates of infection in another. Freshwater fish communities in Trinidad have recently been invaded by a generalist parasitic nematode. This event, combined with our long-term mark-recapture studies of these communities, which began long before the invasion, presented a replicated natural experiment. In this experiment, we measured how host demographic rates responded to two 'treatments': stage of parasite establishment (before, and 1-2 years, 3-5 years and 6-8 years after invasion) and type of community (killifish-guppy communities and killifish-only communities). This design allowed us to infer the direct and indirect impacts of the parasite invasion on killifish communities and determine how the presence of guppies altered infection rates in killifish. The parasitic invasion drastically altered killifish-guppy communities: the ratio of killifish to guppies changed from 1:2 before the invasion to 1:16 after the invasion. Living with guppies amplified the effects of the parasite on killifish, such that parasite-related mortality rates of large adult killifish were twice as high in communities with guppies compared to those without. This effect was driven by a doubling of infection rates in large killifish that live with guppies. In a parallel study, we identified the same patterns of size- and community-dependent infection rates of killifish in five separate river systems, implying that this pattern is general in this system. Our study provides mechanistic insight into how parasites alter community structure under natural conditions, via their direct and indirect impacts on host demographic rates. Our work highlights the value of long-term field studies for our understanding of the impact of parasites on community structure and of ecological interactions in general.
Climate warming, acorn masting and the dynamics of rodent populations: Comparing long-term studies.
Keesing F, LaDeau SL, Canham CD … +2 more , Oggenfuss K, Ostfeld RS
J Anim Ecol · 2026 Jul · PMID 42003520 · Publisher ↗
Pulsed resources, including mast production by forest trees, often have knock-on effects on consumer populations and their prey, predators, parasites and mutualists. Response by small rodents to fluctuating acorn product...
Pulsed resources, including mast production by forest trees, often have knock-on effects on consumer populations and their prey, predators, parasites and mutualists. Response by small rodents to fluctuating acorn production in temperate forests is a widespread example. Long-term research in Maine, USA, recently suggested combined effects of a warming climate and forest maturation on acorn production by red oak trees, leading to directional increases in average population density and body mass of white-footed mice. To foster reproducibility in long-term ecological research, we analysed data from our long-term study in southeastern New York, USA, which used similar field methods. Such a comparison allowed us to assess impacts of climate warming and forest growth on the same pulsed resource and responses by the same consumer species over time and at different latitudes. Despite a clear directional increase in mean minimum temperature and considerable growth in the average size and total basal area of trees during our 33-year study, neither acorn production by red oak trees nor abundance of white-footed mice showed directional increases. Similarly, average body mass of the mice did not change through time. Abundance of mice in mid-summer increased with increasing red oak acorn production the prior autumn. Mouse abundance also was higher in warmer years, although the effect of acorn abundance on mice was stronger. We found no evidence that temperature modified the acorn-driven population responses by mice. Long-term studies are notoriously hard to maintain and even harder to replicate between sites. The direct comparison of similar studies between Maine and New York provides an opportunity to assess the generality of mechanistic models linking climate change, mast seeding and consumer responses.
From steps to home ranges: How habitat disturbance influences the movement drivers of an arboreal primate.
Cárdenas-Navarrete A, Van Belle S, Lara-García U … +2 more , Guzmán-Aguilar M, Razafindratsima OH
J Anim Ecol · 2026 Apr · PMID 42003505 · Publisher ↗
The persistence of animal populations in anthropogenic landscapes often depends on adjusting their foraging and movement strategies to environmental changes that involve energetic trade-offs. However, it remains unclear...
The persistence of animal populations in anthropogenic landscapes often depends on adjusting their foraging and movement strategies to environmental changes that involve energetic trade-offs. However, it remains unclear how ecological resilience translates into movement flexibility and which factors influence animal movement in modified environments. Howler monkeys (Alouatta spp.) are known to cope with significant anthropogenic pressure across their range. We examined how a gradient of habitat disturbance alters intrinsic traits of black howler monkeys (A. pigra) and extrinsic habitat characteristics, and how these factors, in turn, drive their movement. We monitored six groups of black howler monkeys in southeastern Mexico for 1 year, collecting data on movement, activity, diet, neighbouring-group presence, food availability and microclimate. We developed intrinsic and extrinsic models to identify the main drivers of movement across three spatiotemporal scales. Our results revealed scale-dependent responses to disturbance. At the smallest scale (5-min steps), movement probability increased with folivory levels and proximity to neighbouring groups but was significantly constrained by high temperatures. At the intermediate scale (daily paths), resource sparseness led to longer daily travel distances, while group crowding in isolated fragments increased path circuity, reducing travel efficiency. Finally, at the broadest scale (use of space), groups in highly disturbed sites exhibited up to 99% seasonal home range overlap, indicating spatial saturation and a lack of buffering capacity against environmental stochasticity. Our analyses show that while black howler monkeys exhibit behavioural flexibility, their capacity to cope with anthropogenic disturbance is limited by physiological and spatial constraints. As human activities continue to alter ecosystems, animals must adjust their strategies to navigate changing habitats and shifting resource availability; however, when environmental limits exceed an organism's inherent flexibility, populations may face an increased risk of local extinction.
Population trends and variability within bird communities are amplified by intense land use.
Guerber J, Fontaine C, Thébault E
J Anim Ecol · 2026 Jun · PMID 42003499 · Publisher ↗
Human activities affect wild communities through significant long-term changes in population abundance as well as changes in short-term fluctuations. However, studies that focus on one of these stability components tend...
Human activities affect wild communities through significant long-term changes in population abundance as well as changes in short-term fluctuations. However, studies that focus on one of these stability components tend to overlook the other. Using community time-series data from the French Breeding Bird survey, we investigate the variations of community-scale long-term changes (population trends) and short-term fluctuations (detrended variability) across habitat categories and with land use intensity for 905 communities in continental France. We show that communities within agricultural and urban habitats were less stable than woodland communities for both components of stability. Moreover, within habitat categories, only detrended variability increases with land use intensity, while the drivers of local long-term population changes remain to be elucidated. These findings highlight that measuring several stability dimensions provides a better understanding of the links between local land use and community temporal dynamics.
Rising temperature non-additively alters how different dimensions of biodiversity affect ecosystem-scale processes.
Richards SP, Hesselbarth MHK, Allgeier JE
J Anim Ecol · 2026 Apr · PMID 41989067 · Publisher ↗
Improving our ability to predict when and how biodiversity mediates ecosystem processes requires greater consideration of how different dimensions of biodiversity, such as species-specific physiology or behaviour, can in...
Improving our ability to predict when and how biodiversity mediates ecosystem processes requires greater consideration of how different dimensions of biodiversity, such as species-specific physiology or behaviour, can independently and interactively affect these processes. Global change drivers, such as increased temperature, can also alter organismal metabolism in ways that may interact with different dimensions of biodiversity, further reducing predictability. Using an individual-based model of a seagrass-patch reef ecosystem, we quantified (1) how species-level physiological traits of two common reef fish, (2) foraging behaviours and (3) increasing water temperatures interacted to affect ecosystem-level primary production (PP) via consumer nutrient excretion. At ambient temperature, physiology more strongly regulated ecosystem PP than behaviour, which primarily influenced where PP occurred. Increased temperature strongly independently resulted in greater ecosystem PP until a threshold whereafter ecosystem PP drastically decreased for both fish species. Temperature strongly interacted with physiology to non-additively increase ecosystem PP but only weakly interacted with behaviour due to underlying metabolic mechanisms. Our study highlights the importance of species-level physiology for regulating ecological processes and that increased temperatures will alter biodiversity-ecosystem process relationships in unpredictable ways. Importantly, because we quantified both the direct effects of physiology and behaviour on nutrient supply via excretion and the indirect effects of this on primary production, we were able to determine that quantifying consumer-mediated nutrient supply alone was insufficient to predict ecosystem-scale primary production. Our findings emphasize that understanding the mechanisms by which biodiversity affects ecosystems requires quantifying ecosystem-scale responses, which also places findings at scales relevant for conservation.
Drivers of age at first reproduction in the wandering albatross (Diomedea exulans): Demographic factors, environmental conditions and sex-specific responses.
Rouby E, Van de Walle J, Plard F … +6 more , Delord K, Aubry LM, Barbraud C, Bonnet T, Weimerskirch H, Jenouvrier S
J Anim Ecol · 2026 Jun · PMID 41982043 · Publisher ↗
Age at first reproduction is an important life-history trait that marks the beginning of reproductive allocation in long-lived organisms and drives patterns of life-history strategies. Demographic factors and environment...
Age at first reproduction is an important life-history trait that marks the beginning of reproductive allocation in long-lived organisms and drives patterns of life-history strategies. Demographic factors and environmental conditions likely affect age at first reproduction through multiple pathways: food resources availability and energy storage from birth to recruitment, competition for breeding sites and mate availability. Using a unique 35-year dataset of individual-based mark-recapture data from a wandering albatross (Diomedea exulans) population at Crozet (southern Indian Ocean), we investigated how demographic factors and environment influence age at first reproduction. The population experienced major fluctuations, declining by 50% in the 1970s before partially recovering in the 1980s. It was also exposed to important environmental changes, including variations in large-scale climate phenomena and changes in subtropical anticyclone systems like the Mascarene high pressure system. We used multi-event hidden Markov models to estimate age-specific survival and breeding probabilities for each sex separately. From these models, we estimated the age at first reproduction through absorbing Markov chains while accounting for imperfect detection. We investigated how demographic factors (population density at birth and mate availability at recruitment) and environmental conditions (at birth and recruitment) influenced age at first reproduction through their effects on survival and breeding probabilities. Age at first reproduction declined across cohorts for both sexes from 1970 to the mid-1980s, then stabilized. Females recruited at 9.0 years in early cohorts versus 7.5 years in later ones; males declined from 10.2 to 9.2 years. Environmental conditions at birth, particularly the El Niño Southern Oscillation and the Mascarene high, influenced recruitment timing through delayed effects of natal condition on breeding probability rather than survival. Mate availability strongly facilitated earlier recruitment in both sexes, while natal population density delayed male recruitment specifically. Recruitment timing in wandering albatrosses is shaped primarily by developmental programming during the natal period rather than by immediate environmental triggers at sexual maturity, with mate availability and population density modulating these early-life effects in sex-specific ways. Given that recruitment is an important life-history event linked to population-level reproductive rates, accurate demographic projections require models accounting for cohort-specific effects under changing environments.
Complex multitrophic species interactions and fitness costs: Intricate consequences of jasmonate and salicylate induced plant defences.
Kersch-Becker MF, Pinheiro GP, Schweller TS … +4 more , Pareja M, Pocius VM, Trigo JR, Romero GQ
J Anim Ecol · 2026 Apr · PMID 41982000 · Publisher ↗
Induced plant defences regulated by jasmonic acid (JA) and salicylic acid (SA) initiate a cascade of effects, from defence expression to changes in arthropod community structure and species interactions that can ultimate...
Induced plant defences regulated by jasmonic acid (JA) and salicylic acid (SA) initiate a cascade of effects, from defence expression to changes in arthropod community structure and species interactions that can ultimately influence plant fitness. Yet the long-term consequences of these processes remain poorly understood, particularly in perennial tropical systems. We investigated how activation of JA and SA signalling pathways shapes arthropod community composition and plant reproductive success in Trichogoniopsis adenantha (Asteraceae), a glandular trichome-bearing shrub native to the Brazilian Atlantic rainforest. Using chemical elicitors, we induced JA and SA defences for up to 16 months and monitored herbivore and predator assemblages, herbivory patterns, trichome expression, pyrrolizidine alkaloid concentrations and plant short-term fecundity. JA-elicited plants exhibited higher pyrrolizidine alkaloid levels in flowers, reduced leaf herbivory and lower seed damage by pre-dispersal seed predators. However, these plants experienced increased colonization by sap-feeding insects. In contrast, SA-elicited plants were more vulnerable to chewing herbivores but more resistant to sap-feeders. Despite similar reductions in seed predation across both treatments, JA and SA induction significantly reduced ovary fertilization, likely due to changes in floral traits and decreased pollinator visitation, ultimately imposing substantial fitness costs. Additionally, seasonal turnover in arthropod communities was accompanied by temporal variation in how defences structured species composition and abundance. Our findings demonstrate that phytohormone-mediated defences can simultaneously induce resistance and susceptibility across herbivore guilds, with divergent impacts on predator associations. Although defence induction reduced herbivore damage, it compromised short-term fecundity, revealing trade-offs between defence and reproduction. By linking induced defences to multitrophic interactions over time, this study highlights the ecological complexity of plant defence strategies in biodiverse tropical ecosystems.
Season and human footprint weaken the negative effect of temperature on the intraspecific metabolic scaling exponent of wild brown trout populations.
Xu M, Arranz I
J Anim Ecol · 2026 Jun · PMID 41981745 · Publisher ↗
Metabolic scaling fundamentally sets the pace of life in almost all organisms. Research on the metabolic scaling exponent has been largely limited to theoretical and controlled experimental studies, yet causal understand...
Metabolic scaling fundamentally sets the pace of life in almost all organisms. Research on the metabolic scaling exponent has been largely limited to theoretical and controlled experimental studies, yet causal understanding of how ecological factors shape metabolic scaling in real-world conditions is lacking. In this paper, our aim is to develop and test an inferential model for the metabolic scaling exponent of free-living animals. Our inferential model is based on a constraint-based ecological theory and uses the empirical individual size distribution (ISD) as data input since it contains ecological information on the resource partitioning among individuals within a population. We apply the parameterized Maximum Entropy Theory of Ecology (pMETE) to predict the ISDs and estimate the intraspecific metabolic scaling exponent using individual size data of wild brown trout populations in more than 2000 stream samples in France. Using structural causal modelling, we assess the causal effect of water temperature on the metabolic scaling exponent of brown trout, taking into account other biological and environmental variables. Our findings reveal that the exponent estimated from pMETE averages 0.83, exceeding theoretical expectations (e.g. 0.67 or 0.75), yet aligning with some previous metabolic scaling studies on trout species. Controlling the confounding biases of season and human footprint does not alter the negative effect of temperature on the exponent, but renders it insignificant and reduces its effect size by 54%-62%. This suggests that the true causal impact of temperature on metabolic scaling can be overestimated when season and human footprint are neglected. Our study provides new avenues to infer the metabolic scaling of free-living animals and to assess the causal effects of environmental factors on the metabolic scaling exponent at large spatial and temporal scales, broadening metabolic scaling research in the context of global change. Our modelling framework can be applied to other wildlife populations where individual size data are available.
Mechanisms of freshwater zoogeochemistry: A review and meta-analysis of animal impacts on ecosystem function.
Lopez JW, Michael TC, Atkinson CL … +19 more , Lodato MB, Morris LM, Plont S, Smith CR, Akamagwuna FC, Albertson LK, Breault DK, Dorris JD, Fritz SF, Haase J, Hebert TA, Hensley AC, Hopper GW, Kuczek MP, Morin JN, Oakland HC, Siders AC, Sitati A, Tumolo BB
J Anim Ecol · 2026 Apr · PMID 41969022 · Publisher ↗
Freshwater ecosystems are under immense pressure from global environmental change. These stressors have led to biogeochemical alterations, rapid rates of defaunation and losses of associated animal-driven ecosystem funct...
Freshwater ecosystems are under immense pressure from global environmental change. These stressors have led to biogeochemical alterations, rapid rates of defaunation and losses of associated animal-driven ecosystem functions. Zoogeochemistry provides a unique perspective on the dual challenges of global change and defaunation in freshwater ecosystems, but zoogeochemical frameworks that explicitly link conservation biology with biogeochemistry have not yet been fully embraced by freshwater ecologists. We conducted a systematic review and meta-analysis of the mechanistic roles that animals play in freshwater biogeochemistry, with the aim of advancing the application of zoogeochemistry in freshwaters. We reviewed 14 major mechanisms of freshwater zoogeochemistry. Our review shows that a diversity of taxa impact ecosystem-level elemental pools and fluxes, within and across freshwater ecosystem boundaries. However, these effects are not always placed in context at the ecosystem level, which limits the scope of our meta-analysis. Zoogeochemical impacts tended to be stronger in wetlands and lakes than in streams and estuaries. Consumption, excretion, and respiration had the strongest direct impacts on elemental pools and fluxes; bioturbation, consumption, and egestion had the strongest indirect impacts. These mechanisms often interacted, generating complex influences on elemental pools and fluxes. However, creative experimental designs can be used to isolate individual mechanisms, allowing complex effects with multiple mechanisms to be incorporated into ecosystem models. Quantifying and modelling zoogeochemical effects in freshwater ecosystems will allow ecologists and managers to make informed decisions that balance biodiversity conservation with healthy ecosystem function.
Yellow fever outbreak temporarily changes dispersal patterns in an endangered primate.
Ponchon A, Choquet R, Martins AF … +3 more , Ruiz-Miranda C, Albert CH, Romano V
J Anim Ecol · 2026 Jun · PMID 41968875 · Publisher ↗
Disease outbreaks can severely affect populations in the wild. However, their consequences on individual social behaviour and population demography are poorly understood. We used a multi-site capture-recapture model to i...
Disease outbreaks can severely affect populations in the wild. However, their consequences on individual social behaviour and population demography are poorly understood. We used a multi-site capture-recapture model to investigate the impacts of a yellow fever outbreak on the endangered golden lion tamarin Leontopithecus rosalia, in the fragmented Atlantic forest, Brazil. Annual adult survival rate severely declined in 2017-2018, coinciding with the outbreak period. Simultaneously, dispersal patterns changed temporarily, with a reduction of settlement time for individuals dispersing within the same forest fragments, and a 10-fold increase of dispersal rates between forest fragments, from 0.004 ± 0.002 to 0.043 ± 0.015. On the contrary, dispersal rates within forest fragments slightly decreased, from 0.036 ± 0.006 to 0.028 + 0.011. The number of social groups remained stable until the end of the outbreak and increased afterwards while the number of individuals composing groups decreased during the outbreak and remained lower afterwards. Altogether, our results indicate a spatial rearrangement of individuals during the outbreak potentially due to non-random mortality leading to changes in social group structure. They advocate for a better integration of host movements, host social behaviour and habitat connectivity when evaluating species response to infectious diseases.
Consumption competition by a parasitoid wasp opens a window of survival under intraguild predation.
Martínez-Martínez F, Sahraoui M, Xuéreb A … +3 more , Charalabidis A, Pekas A, Frago E
J Anim Ecol · 2026 Jun · PMID 41968382 · Publisher ↗
Intraguild predation is a common type of omnivory that occurs when two competing consumers that share a resource also prey on each other. Theory predicts limited conditions under which species engaging in this interactio...
Intraguild predation is a common type of omnivory that occurs when two competing consumers that share a resource also prey on each other. Theory predicts limited conditions under which species engaging in this interaction can coexist, but in nature intraguild predation is widespread. In asymmetrical intraguild predation one predator feeds on another but not vice-versa, and the dominant predator usually excludes the subordinate one, unless the latter is more efficient at exploiting the shared prey. Despite decades of research, the mechanisms enabling coexistence of such subordinate predators remain poorly understood. Here, we combine a long-term multigenerational experiment with behavioural tests to investigate the population dynamics of the parasitoid wasp Aphidius colemani, when sharing the aphid prey Myzus persicae with two dominant predators: the ladybird Adalia bipunctata and the brown lacewing Micromus angulatus. These predators act as dominant or intraguild predators because they can feed on both healthy and parasitized aphids. We found that in the presence of predators, the parasitoid had smaller population sizes and quicker extinction times. Unexpectedly, however, the parasitoid had a negative impact on the lacewing, but not on the ladybird. Behavioural experiments revealed that (1) late parasitoid stages (mummies) were seldom predated by intraguild predators, (2) the lacewing had lower consumption rates and (3) the ladybird preferentially consumed young parasitized aphids. These results suggest that the slower-feeding lacewing allowed parasitoids to develop into protected mummies and capitalize aphid resources, a case of consumption competition. The faster consumption rates of the ladybird narrowed the window of parasitoid survival, a limitation further exacerbated by this predator's aggressive behaviour that preferentially consumed early instars of its competing natural enemy. Consumption competition can therefore allow survival under intraguild predation and influence the persistence of species in communities with multiple natural enemies.
Using spatially-nested hierarchical species distribution models to estimate current and future distributions of a cryptic species at a regional scale.
Banks KM, Edwards OM, Zhang B … +1 more , Reichert MS
J Anim Ecol · 2026 May · PMID 41960611 · Publisher ↗
Understanding a species' conservation status requires evaluating its ecological relationships, contemporary distribution and vulnerability to future environmental change. Species distribution models (SDMs) are widely use...
Understanding a species' conservation status requires evaluating its ecological relationships, contemporary distribution and vulnerability to future environmental change. Species distribution models (SDMs) are widely used for these purposes, but regional-scale applications often suffer from extrapolation and niche truncation, reducing model transferability. Spatially nested hierarchical SDMs (N-SDMs), which integrate data across multiple spatial scales, offer a promising solution but remain underutilized in regional conservation research. Crawfish frogs (Rana areolata) are a cryptic grassland species reliant on crayfish burrows that have experienced declines across their range and are data deficient in Oklahoma. This study combines comprehensive regional field surveys across Oklahoma with large-scale occurrence data from GBIF using an N-SDM framework to characterize the species' current regional distribution, identify factors influencing habitat suitability and forecast future range shifts under climate and land-use change. Additionally, we compared the performance of N-SDMs to regional only and rangewide SDMs and assessed how niche truncation and extrapolation influence model performance and transferability under future environmental conditions. We documented R. areolata at 303 survey locations and found no evidence of historical county-level extirpations, with our models suggesting large amounts of suitable habitat in eastern Oklahoma. Our rangewide SDM lacked the resolution and regional predictive performance necessary for regional conservation planning. While our regional-only SDM had higher predictive performance, it suffered from substantial extrapolation and niche truncation, leading to predictions of significant habitat loss under future conditions. In contrast, our N-SDMs had the highest regional predictive performance, mitigated the effects of niche truncation and extrapolation and projected no change or a slight increase in future habitat suitability. Our findings highlight the advantages of N-SDMs for improving model predictions and informing conservation assessments. Failure to account for niche truncation and extrapolation can lead to poor predictions and misguided conservation decisions. We advocate for the broader adoption of this approach in regional-scale studies to improve predictions of species responses to environmental change and more effectively assess species status at a regional level.
Spider mite genotypes with higher growth rate suffer more from competition but exert stronger reproductive interference.
Cruz MA, Zélé F, Gaspar R … +4 more , Santos R, Rodrigues LR, Sousa VC, Magalhães S
J Anim Ecol · 2026 Jun · PMID 41940755 · Publisher ↗
Within-species individual variation has been gaining increased attention in ecological studies of species interactions. Yet, these studies rarely consider genetic variation and potential genetic correlations among traits...
Within-species individual variation has been gaining increased attention in ecological studies of species interactions. Yet, these studies rarely consider genetic variation and potential genetic correlations among traits. Moreover, traits beyond those associated with trophic interactions are mostly overlooked. Filling these gaps is important to fully understand the relevance of trait variation in both the ecology and evolution of species interactions. We addressed this using inbred lines of Tetranychus cinnabarinus, a spider mite species that often engages in antagonistic interactions with its congeneric T. urticae. Specifically, we measured (a) the intrinsic growth rate and the sex ratio in the absence of food competition and reproductive interference; (b) food competition against a density gradient of conspecific or heterospecific competitors in the absence of reproductive interference; (c) reproductive interference in the absence of food competition; and (d) the body size of adult females and males. We found significant genetic variance (i.e. broad-sense heritability) among lines for all variables except for the effect of T. cinnabarinus on its heterospecific competitor via food competition. Moreover, we showed that lines with higher intrinsic growth were more sensitive to intra- and interspecific competition for food but exerted stronger reproductive interference on heterospecifics. In addition, the higher the proportion of sons produced by a line, the more resilient it was to reproductive interference but also the lower its growth rate. No genetic correlations were found between any variable and body size. Our results indicate that considering genetic correlations among traits involved in both trophic and sexual interactions is key to understanding the role of individual variation in species interactions and their evolution.
Development time and host-parasitoid stability: An experimental test.
Cronin JT, Reeve JD
J Anim Ecol · 2026 Jun · PMID 41937338 · Publisher ↗
The duration of specific life stages and relative lengths of the predator and prey life cycles can, in theory, exert strong influences on population dynamics and may be important considerations in managing pest outbreaks...
The duration of specific life stages and relative lengths of the predator and prey life cycles can, in theory, exert strong influences on population dynamics and may be important considerations in managing pest outbreaks. However, rigorous experimental tests of this theory do not exist. We conducted a microcosm experiment using the cowpea weevil (Callosobruchus maculatus) and its parasitoid (Anisopteromalus calandrae) to assess how a 60% increase (long-duration treatment) or 60% decrease (short-duration treatment) in the invulnerable (late larval to mid pupal) host stage affected host-parasitoid population dynamics. We predicted that stability is most likely for microcosms in the short-duration treatment, whereas generation cycles should occur for the long-duration and control treatments, with a longer period in the long-duration treatment. Our results largely support these predictions. In the control treatment, persistent oscillations occurred with a period of about one generation, consistent with theory. The long-duration treatment produced cycles similar in period and strength to the control, rather than predicted longer period ones. As expected, cycles disappeared in the short-duration treatment and host densities were suppressed by 41%-49% relative to the other treatments. Variability in host densities in the short-duration treatment was high, likely a consequence of demographic stochasticity in small populations, whereas variability in parasitoid densities was 24%-27% lower than in the other treatments. Complementary simulation models that closely matched the biological details and protocols used in the experiment reproduced the observed dynamics in the short-duration and control treatments. The oscillatory period observed in the long-duration treatment was also replicated when stronger, scramble-type competition in the weevil attack process was incorporated into the model. We conclude that age structure and development time are critical determinants of host-parasitoid population dynamics and should be explicitly considered in the selection of biological control agents and in evaluations of program success or failure.
Torpor-assisted migration: Regular use of shallow torpor reduces rest-phase energy expenditure for songbirds during migration.
Leys RAC, Hou L, McGuire LP
J Anim Ecol · 2026 Mar · PMID 41913559 · Publisher ↗
Endothermy evolved independently in birds and mammals providing many fitness benefits but requiring substantial energy to maintain a stable body temperature. Many endotherms have evolved heterothermic strategies to cope...
Endothermy evolved independently in birds and mammals providing many fitness benefits but requiring substantial energy to maintain a stable body temperature. Many endotherms have evolved heterothermic strategies to cope with daily and seasonally cold weather and reduced food availability. Heterothermy has been studied extensively in mammals, but comparatively few studies have considered heterothermy in birds. Heterothermy may be beneficial to migrating endotherms to reduce thermoregulatory energy expenditure and enhance refuelling rate at stopover sites, known as torpor-assisted migration. We hypothesized that migratory birds use shallow torpor to reduce rest-phase energy expenditure. We tested four species for shallow torpor use during migration: Brown Creeper Certhia americana, Golden-crowned Kinglet Regulus satrapa, Ruby-crowned Kinglet Corthylio calendula and Yellow-rumped Warbler (Myrtle subspecies) Setophaga coronata coronata. We measured body temperature using temperature-sensitive PIT tags and metabolic rate using open-flow respirometry at night. All four species from three different passerine families (Regulidae, Certhiidae and Parulidae) used shallow torpor frequently (69%-98% of birds per species) over a range of ambient temperatures (-1 to 30°C) during migration. Body condition was the main driver of torpor use. Birds with smaller fat stores used torpor more deeply and frequently than fatter birds, achieving up to 42% lower metabolic rates and saving more energy. Contrary to studies on deep torpor, ambient temperature had no effect on the frequency or depth of torpor use. Shallow torpor has wide-ranging implications for the energetics of migration with broader impacts on survival and reproduction and provides an opportunity to compare heterothermic strategies between birds and mammals.
Predation on sea turtles at sea: A multi-source synthesis and research perspectives.
Casale P, Servolini A, González-Bernardo E … +17 more , Baldi G, Tagliolatto A, Foley A, Bresette M, Welsh R, Freggi D, Margaritoulis D, Kaska Y, Levy Y, Sassoon S, Crespo-Picazo JL, García-Párraga D, Barret M, Jaquemet S, Salvemini P, Holmes B, Moore ABM
J Anim Ecol · 2026 Jun · PMID 41852291 · Publisher ↗
Predation is a key ecological process shaping sea turtle populations, yet - unlike predation of eggs, hatchlings and adults on nesting beaches - its role at sea remains poorly quantified due to observational challenges....
Predation is a key ecological process shaping sea turtle populations, yet - unlike predation of eggs, hatchlings and adults on nesting beaches - its role at sea remains poorly quantified due to observational challenges. This study synthesizes multiple, rarely integrated data sources-including unpublished data-to examine global patterns of sea turtle predation at sea. Sources include field observations (turtles found stranded, nesting, admitted to rescue centers, or captured in-water for research), literature records, predator diet data, and non-conventional online sources (NCS; images and videos). A literature review compiled 206 report/predator/turtle species/turtle life stage/area combinations involving all seven extant sea turtle species and 51 predator species. Although predators span several taxa (including teleost fishes, crocodilians, and mammals), most reports involve a few shark species. To estimate predation rates, we analysed 156,726 turtle records (dead or alive), of which 5,107 individuals (3.3%) showed evidence of shark-bite injuries. These rates varied significantly among species, size classes, regions, and over time. Stomach content analysis of 3,927 sharks from 12 species identified turtle remains only in tiger and white sharks, with tiger sharks emerging as the dominant predator. NCS yielded 34 shark-turtle interactions, 73% of which were videos that offered rare insights into sea turtle defensive behaviours such as dorsal shielding, rapid manoeuvring, fleeing, and even counterattacks. Together, these multiple approaches provide complementary insights and highlight the dominant role of large sharks, particularly tiger sharks, in sea turtle predation. However, current knowledge is largely confined to predation in neritic waters because of the inherent difficulties of studying this topic in oceanic environments. Predation on small juveniles and in oceanic waters remains the most significant knowledge gap due to the likelihood of whole-body ingestion and occurrence in oceanic habitats. Tracking such early life stages may become feasible with advances in tag miniaturization. Meanwhile, visible shark-bite injuries on large turtles-if adequately standardized-represent a promising tool for monitoring spatial and temporal trends in predation pressure on large turtles in coastal waters. With improved data collection, analytical methods, and citizen science contributions through NCS, we can begin to address critical knowledge gaps in the at-sea predation ecology of sea turtles.
Tracing the Battle: Role of mucus trails in information warfare between predator snail and prey limpet.
Wada Y, Noda T, Ida TY … +2 more , Iwatani Y, Sato T
J Anim Ecol · 2026 May · PMID 41845901 · Publisher ↗
Predator-prey interactions have long been recognized as important selective forces in the evolution and maintenance of multiple traits in both predators and prey. Certain animal species leave information intentionally or...
Predator-prey interactions have long been recognized as important selective forces in the evolution and maintenance of multiple traits in both predators and prey. Certain animal species leave information intentionally or unintentionally, in the form of urine, faeces, feeding traces and chemical trails, even after they have moved. This residual information, left behind by animals, has the potential to affect predation efficiency. However, information warfare-the use of information between predator and prey, in which predators exploit prey cues to increase predation efficiency, while prey exploit predator cues to reduce it-remains largely unexplored, especially in the context of residual information. Marine gastropods leave a mucus trail that contains individual information as they crawl. In this study, we investigated the existence of information warfare between the predator snail Reishia clavigera and the prey limpet Siphonaria sirius through mucus trails. We observed the responses of predators and prey to their respective mucus trails under laboratory conditions. The predators followed the prey's mucus trails. In contrast, the prey exhibited movements, such as looping, upon confrontation with the predator's mucus trails. The looping behaviour reduced the probability of the predator reaching the endpoint of the prey's mucus trail. These results suggest a potential strategy whereby predators exploit prey mucus trails for localization, along with a counter-strategy through which prey minimize the risk of detection. Our findings provide novel insights into how information shapes predator-prey interactions, indicating the potential existence of an information-induced arms race.
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