The Journal Of Animal Ecology[JOURNAL]
Sun
200 papers
Pollinator community composition and pollen resource use in calcareous grasslands under different landscape contexts across Europe.
Bernhardsson O, Valdaru E, Aavik T … +15 more , Baltz LM, Dostálek T, Ende LM, Jegham K, Kivastik M, Münzbergová Z, Pánková H, Plue J, Pluta P, Reinula I, Sõber V, Theodorou P, Träger S, Viljur ML, Jacquemyn H
J Anim Ecol · 2026 Jul · PMID 42387990 · Publisher ↗
Plants and pollinators interact in complex ways to facilitate plant reproduction and increase insect fitness. While some plant and insect species show high levels of specialization, others engage in more generalized inte...
Plants and pollinators interact in complex ways to facilitate plant reproduction and increase insect fitness. While some plant and insect species show high levels of specialization, others engage in more generalized interaction patterns. However, interactions between plants and pollinators are dynamic and can change in response to altered environmental conditions. Land-use change is one of the main factors that may affect the interactions between plants and insects, as the associated shifts in land cover, habitat availability, and habitat connectivity are expected not only to directly impact pollinator and plant diversity, but also to influence the foraging behaviour and resource use of pollinators. In this study, we compared pollinator community composition, pollinator resource use and the structure of the network of plant-pollinator interactions among calcareous grasslands embedded in agricultural landscapes differing in grassland amount, connectivity and surrounding land use across five European countries. Pollinator surveys were conducted to assess variation in their communities, while pollen metabarcoding was conducted to assess the interactions between plants and pollinators. Network analyses were used to investigate whether the overall structure of the network of interactions differed between landscapes. Our results show substantial differences in pollinator communities and pollen composition between grasslands, leading to strong interaction turnover. However, despite strong species turnover, dominant families such as Asteraceae (plants) and Syrphidae (insects) remained consistently common across sites, suggesting considerable functional redundancy. In addition, pollinators consistently foraged on plant species in the wider landscape, regardless of variations in landscape composition and habitat connectivity. This likely contributed to the limited differences in overall network structure, with similar levels of connectance, nestedness, and modularity across landscapes. Synthesis. Overall, these findings indicate that pronounced differences in pollinator communities and opportunistic foraging strategies resulted in large interaction turnover, but these shifts did not translate into major changes in overall network structure, likely due to functional redundancy. Future long-term monitoring studies are needed to assess whether these network properties remain stable through time under continued landscape change.
A global comparison of structural properties across ecological network types: The role of connectance, degree distribution and sampling inconsistencies.
García-Callejas D, Thébault E, Lajaaiti I … +3 more , Martins LP, Laux L, Kéfi S
J Anim Ecol · 2026 Jul · PMID 42387845 · Publisher ↗
Understanding how the structure of ecological communities varies across biotic and abiotic dimensions is a fundamental goal in ecology. This challenge is now approachable due to the increasing availability of data on com...
Understanding how the structure of ecological communities varies across biotic and abiotic dimensions is a fundamental goal in ecology. This challenge is now approachable due to the increasing availability of data on community structure across the globe. Ecological communities are often defined with respect to the guilds considered and the interactions they engage in, but it is unclear whether interactions of different types respond similarly to large-scale environmental gradients. Therefore, we lack a deeper understanding of how the emergent structure of interaction networks varies across biogeographical gradients, and how this effect may change depending on their constituent interaction types. Here, using a unique dataset of 952 networks across the globe, we provide a first comparison of network structural metrics and their large-scale variability for five overarching interaction types (feeding, frugivory, herbivory, parasitism and pollination). We show that degree distribution, but not connectance alone, helps us understand the observed network structures, and this pattern is maintained across interaction types (with the partial exception of food webs). Moreover, degree distribution descriptors are statistically related to differences across studies, which represent a proxy for variability in sampling and network construction methods. Environmental factors show inconsistent effects on network degree distribution, and food webs are generally more sensitive to changes in environmental factors than networks of other interaction types. By analysing common descriptors of the degree distributions of ecological networks, this study underscores for the first-time generalities and differences across networks of different interaction types and their response to environmental and anthropogenic factors.
Native habitat affinities predict fish invasions with post-invasion habitat shifts.
Chaikin S, Gavriel T, Deveto A … +2 more , Malamud S, Belmaker J
J Anim Ecol · 2026 Jul · PMID 42387289 · Publisher ↗
Identifying habitat affinities and demographic characteristics associated with high invasion potential is a key ecological challenge. However, testing invasion hypotheses exclusively in the invaded range is inherently fl...
Identifying habitat affinities and demographic characteristics associated with high invasion potential is a key ecological challenge. However, testing invasion hypotheses exclusively in the invaded range is inherently flawed, as it conflates the intrinsic pre-adaptations that allowed the species to invade with the habitat shifts they adopted post-invasion. To elucidate how invasion potential is related to habitat affinities and post-invasion ecological dynamics, we investigated the unique paired-basin system of the Red Sea and Eastern Mediterranean. We captured in situ realized niche data (e.g. abundance, depth limits and habitat affinities) using standardized stereo underwater video surveys across 179 populations. We then applied a three-comparison framework to evaluate native-range invasion potential, post-invasion habitat shifts and recipient-community integration. Within the native Red Sea, future introduced species were distinct from non-introduced natives primarily due to their lack of reliance on coral habitats, shallower minimum depth limits, and broader habitat and depth ranges. Comparing the native and invaded ranges of introduced species revealed post-invasion niche shifts. Rather than shifting uniformly, introduced species exhibited high habitat lability, successfully abandoning affinities for tropical substrates to utilize available Mediterranean habitats. Within the Mediterranean, introduced species were assimilated into the recipient community, becoming indistinguishable from natives in habitat use rather than occupying distinct habitats. By synthesizing linear discriminant and mixed-modelling approaches into a cross-validated ensemble index, we prioritized specific Red Sea species as high-risk candidates for future Mediterranean invasion. Ultimately, this in situ framework highlights that while specific native-range habitat filters predict invasion potential, post-invasion habitat lability means that relying solely on native affinities could severely underestimate their spread and impact in novel environments.
Understanding mammal avoidance of human settlements.
Potts JR, Börger L, Tucker MA … +73 more , Ossi F, Yanco SW, Ellis-Soto D, Müller T, Oliver RY, Alves MH, Arnold W, Attias N, Bastille-Rousseau G, Belant JL, Blount JD, Beyer DE, Cagnacci F, Chamaillé-Jammes S, Chan AN, Cole EK, Cornils JS, de Paula RC, DeNicola V, Desbiez ALJ, Dewey SR, Drake D, Egan M, Eikelboom JAJ, Farmer M, Garel M, Goheen JR, Hansen HP, Haugaard L, Hebblewhite M, Heim M, Ježek M, Jordán L, Kamaru DN, Krofel M, LaSharr TN, Leimgruber P, Loison A, Long RA, Loretto MC, Marchand P, Meisingset E, Melzheimer J, Monteith KL, Morgan JJ, Mortensen RM, Mueller R, Mysterud A, Olejarz A, Oliveira T, Panzacchi M, Portas R, Potočnik H, Prins HHT, Prugh LR, Ranc N, Roeder R, Rolandsen CM, Şekercioğlu Ç, Selimovic A, Smiley R, Solberg EJ, Strand O, Sunde P, Toïgo C, Van Moorter B, Verzuh TL, Wachter B, Wagler BL, Whittington J, Wilmers CC, Wittemyer G, Rutz C
J Anim Ecol · 2026 Jul · PMID 42383642 · Publisher ↗
Anthropogenic land conversion is putting increasing pressure on wildlife populations around the world. To mitigate impacts, it is necessary to develop a detailed mechanistic understanding of how animals are affected by d...
Anthropogenic land conversion is putting increasing pressure on wildlife populations around the world. To mitigate impacts, it is necessary to develop a detailed mechanistic understanding of how animals are affected by different types of human activity. A key challenge is to disentangle the effects of static infrastructure, like roads or buildings, and the presence of humans in the landscape. To address this question, we examined if terrestrial mammals altered their movement behaviour around buildings in response to reduced human mobility during COVID-19 lockdowns. We compiled GPS tracking data from 35 study sites across five continents, for 10 carnivore species and 13 herbivore species, totalling >1 million location records from 586 individuals. For each study, we used integrated step selection analysis to test the extent to which animals changed their avoidance of buildings as lockdown took effect, leveraging the recently released Microsoft MLBuildings dataset of global building locations. Analysis of population-level effects revealed that, in areas with high Human Footprint Index (HFI), animals tended to show a significant reduction in their avoidance of buildings during lockdown, but not in low HFI areas. No such trend was detected during equivalent periods in years other than 2020, indicating that behavioural changes were a result of reduced human mobility during lockdowns. Overall, our findings suggest that animals living alongside humans exhibit greater plasticity when people change their behaviour, likely indicating the combined effects of environmental filtering and habituation. More generally, our study provides a critical first step towards developing evidence-based tools for forecasting how wildlife movement behaviour may change in response to different land-use strategies, human activities, conservation interventions or environmental perturbations.
Environmental factors associated with nesting habits and age shape the composition and connection between skin and uropygial gland microbiomes of birds.
Martínez-Renau E, Bodawatta KH, Martín-Platero AM … +7 more , Martín-Vivaldi M, Barón MD, Ruiz-Castellano C, Martínez-Bueno M, Jønsson KA, Poulsen M, Soler JJ
J Anim Ecol · 2026 Jun · PMID 42379884 · Publisher ↗
Bacterial communities on skin and feathers can act as a critical line of defence against pathogenic infections in birds and may originate from secretions produced by the uropygial gland. These secretions reach the bird i...
Bacterial communities on skin and feathers can act as a critical line of defence against pathogenic infections in birds and may originate from secretions produced by the uropygial gland. These secretions reach the bird integument during preening, with the preening effort possibly determining the connectivity between uropygial gland and integument microbiomes. The risk of pathogen infections depends on a number of variables, including environmental conditions (i.e. temperature and humidity), species identity, life-history traits (i.e. cavity vs. open-cup nesters) and life stage (i.e. age). Bacterial symbionts of the host, particularly those of the uropygial gland, may counter such pathogenic infections. We therefore hypothesise that bacterial communities of the uropygial gland differ among host species, age and nesting habits, with higher bacterial diversity in nestlings due to their immature immune system, and in cavity nesters due to potentially increased pathogen exposure. We examined this using 16S rRNA metabarcoding of bacterial communities of the uropygial secretion (N = 352) and uropygial gland skin (N = 339) of nestlings and adults of 26 bird species from 14 families in southern Spain. In accordance with the hypotheses, we find species-specific differences in bacterial communities of uropygial gland skin and secretion, as well as an effect of age, with nestlings showing a higher bacterial diversity, especially in the uropygial gland skin. Additionally, the microbiotas of cavity-nesting species are more diverse and heterogeneous than those of open nesters, with these effects more pronounced in adult and uropygial secretions. Finally, the uropygial gland is relatively larger in cavity- than in open-nester species, which suggests that cavity nesters preen more often than the open nesters. Moreover, we found a stronger sharing of secretion and skin microbes in cavity nesters and nestlings compared to adults and open nesters. Overall, our findings on the effects of age and nest type on structuring bird uropygial gland skin and secretion microbiota imply that age and pathogen risks related to nest environment could drive the external microbiome assembly in birds.
Leukocyte profiles reveal sex and age differences in immune investment in a polygynous bat.
Wilkinson GS, Kaiser JA, Armenta KN … +4 more , Cunningham ASG, Hex SBSW, Lawson AM, Rayner JG
J Anim Ecol · 2026 Jun · PMID 42379146 · Publisher ↗
Developing and maintaining an immune system is critical for vertebrate survival, but when resources are limiting, investment in support of immune function has been hypothesized to trade off with the development and/or ex...
Developing and maintaining an immune system is critical for vertebrate survival, but when resources are limiting, investment in support of immune function has been hypothesized to trade off with the development and/or expression of traits that enhance reproductive success. Species that exhibit extreme polygyny typically have high reproductive skew, which can be expected to result in sex differences in immune investment particularly for those individuals that succeed in reproducing. Furthermore, life history theory predicts that investment in adaptive immunity should decline as an individual approaches maximum lifespan and result in immunosenescence. In this study, we evaluated these predictions by using differential white blood cell counts to assess relative investment in innate versus adaptive immunity over the lifespan of a sexually dimorphic neotropical bat that exhibits extreme polygyny. We also consider whether physiological stress or nutritional condition explains variation in leucocyte profiles. We captured and made blood smears from 511 greater spear-nosed bats, Phyllostomus hastatus, during periods of mating and lactation over 5 years and used a DNA methylation clock, recaptures of animals previously marked at a known age or sex-specific regressions of toothwear on age to estimate age. We measured cortisol concentration from urine samples using gas chromatography, tandem mass spectrometry or an enzyme-linked immunosorbent assay to measure physiological stress and sex-specific residuals of body mass relative to forearm length to measure nutritional state. We found that variation in the neutrophil-to-lymphocyte ratio (NLR) is associated with interactions between sex, age and season. NLR was higher in males than in females in all seasons and increased with age in both sexes, with the slope of age-associated variation steeper in males than in females. Both cross-sectional and longitudinal data revealed that NLR was highest in the mating season. Neither urinary cortisol nor body condition explained NLR variation within seasons. Our findings provide evidence from a long-lived bat that investment in innate immunity increases while adaptive immunity declines over the lifespan. Strikingly, this relationship occurs more rapidly in males than in females consistent with the higher mortality rate observed in males than in females of this highly polygynous species.
Human hunters are no substitute for vanishing apex predators.
Geng Y, Mammides C, He RC … +5 more , Wang L, Luo K, Zhang ZY, Wang B, Quan RC
J Anim Ecol · 2026 Jun · PMID 42358133 · Publisher ↗
The global decline of apex predator populations risks the loss of their crucial ecological functions. This raises a pressing yet contentious question: can human hunters, often termed 'super-predators', functionally subst...
The global decline of apex predator populations risks the loss of their crucial ecological functions. This raises a pressing yet contentious question: can human hunters, often termed 'super-predators', functionally substitute for the complex regulation once provided by their natural counterparts? To investigate this question, we analysed 30,778 camera-trap records from 400 sites in southwestern China (2017-2021). Using propensity score matching (PSM) to control for environmental heterogeneity, we compared wildlife communities across hunter-dominated, apex predator-dominated, and predator-absent sites. Our results showed that hunters fail to replicate the collective and individual ecological functions of natural apex predators (dhole, Asian golden cat, and clouded leopard). Apex predator sites supported the highest species richness and abundance, with 33.0% and 32.5% more species and 49.8% and 44.8% greater abundance than hunter-dominated and predator-absent sites, respectively. The prey species-site network was the most robust at apex predator sites and the weakest at hunter-dominated sites, indicating that hunting increases prey vulnerability to cascading extirpations following habitat loss. Compared with hunter-dominated sites, sites dominated by single-apex predators had distinct species compositions and dominant prey. Prey exhibited prolonged avoidance (up to 2.6 times longer) of hunters compared with any apex predator, coinciding with the weakest network robustness at hunter-dominated sites. Collectively, our findings provide compelling evidence that human hunters cannot replace apex predators in sustaining biodiversity and promoting stable spatial patterns. Our work therefore strongly supports the conservation of natural apex predators and offers crucial insights for regulating human hunting in ecosystem management.
Temperate forest heterogeneity decreases local and landscape-scale spider diversity through habitat filtering despite increasing species turnover.
Stör JL, Rothacher J, Cadotte MW … +8 more , Chao A, Huszarik M, Junginger M, Köstler-Albert L, Mitesser O, Mori AS, Wild C, Müller J
J Anim Ecol · 2026 Jun · PMID 42358129 · Publisher ↗
Spiders are important arthropod predators in temperate forests. Their diversity depends on structurally heterogeneous habitats offering diverse microhabitats. Yet, modern silviculture has homogenized temperate forest str...
Spiders are important arthropod predators in temperate forests. Their diversity depends on structurally heterogeneous habitats offering diverse microhabitats. Yet, modern silviculture has homogenized temperate forest structure at local and landscape scales. The consequences of this homogenization for landscape-level spider diversity, however, remain largely unknown. We sampled spiders using pitfall traps across 234 patches in a large-scale, replicated field experiment at 11 forest sites across Germany. At each site, one treatment district was experimentally heterogenized through canopy gap creation, thinning and deadwood enrichment, and a second homogeneous district remained untreated as a control. We applied a novel meta-analytic framework to compare α-, β- and γ-diversity of spiders between treatment and control districts, standardized for sample coverage along Hill numbers giving increasing weight to abundance and included taxonomic, functional and phylogenetic diversity facets. We also investigated spider community assembly in response to deadwood enrichment, canopy openness and heterogeneous forest structure. Based on 18,540 spider individuals from 206 species, treatment districts exhibited significantly lower γ- and α-diversity across all diversity facets and Hill numbers, particularly when focusing on rare species (q = 0). In contrast, β-diversity increased in treatment districts for phylogenetic and functional diversity across Hill numbers (q = 0, 1, 2). The simultaneous decrease in α- and γ-diversity despite higher β-diversity renders the increase in compositional turnover insufficient to compensate for local diversity losses. Although spiders were more abundant in treatment patches, habitat filtering, rather than niche competition, shaped the community. Our findings corroborate previous results of high spider abundances but lower taxonomic and functional diversity in canopy gaps due to strong habitat filtering effects. However, we demonstrate for the first time that this lower α-diversity is linked to a lower γ-diversity despite increases in β-diversity. Homogenous forests support higher γ-diversity through greater three-dimensional canopy habitat availability. Yet, failure to account for species frequencies using Hill numbers and coverage standardization may result in a substantial underestimation of arboreal spider diversity in pitfall traps. Nonetheless, higher abundances in heterogeneous forests point towards increased prey availability and predator pressure.
Elephant space use and habitat selection change across drought timescales.
Bouwman I, Claassen T, Chase MJ … +3 more , Landen K, Huijbregts MAJ, Tucker MA
J Anim Ecol · 2026 Jun · PMID 42332377 · Publisher ↗
Droughts are globally increasing in duration, frequency and intensity, thereby endangering the survival of wildlife species. Understanding how animals behave during drought is essential to develop conservation measures t...
Droughts are globally increasing in duration, frequency and intensity, thereby endangering the survival of wildlife species. Understanding how animals behave during drought is essential to develop conservation measures that aid wildlife survival and prevent human-wildlife conflict in a changing climate. Yet, little is known about animal behaviour during drought. Specifically, existing work on animal behaviour and drought typically does not account for the timescale and the intensity of the drought. We use 19 years of GPS data from the African elephant (Loxodonta africana), a species at risk from drought, collected in Southern Africa, where droughts are increasingly common. We study if there is a connection (i) between drought and the amount of space elephants use and (ii) between drought and elephant habitat selection. We examine drought conditions using the Standardized Precipitation-Evapotranspiration Index (SPEI) at a 1-month, a 3-month, and a 12-month timescale. We found that elephants had smaller home ranges and movement distances when their environment became drier at a 1-month timescale. Importantly, SPEI at a 1-month timescale was a better predictor of elephant home range size than precipitation and NDVI, suggesting that drought conditions may affect elephant movement through more ways than a lack of precipitation or vegetation greenness. In addition, we found that elephant habitat selection changed as a function of drought conditions at all three timescales, but the direction of the change often depended on the timescale of the drought. We found that elephants were closer to inland water and in areas with lower human population density during drought at a 1-month timescale, but farther from inland water and in areas with higher human population density when drought lasted longer. Overall, our results show that drought conditions, as measured by SPEI, predict elephant movement behaviour. We stress the importance of (i) using a drought index rather than only precipitation levels to examine drought conditions and (ii) considering the timescale at which drought occurs. These insights could help to better understand how animals behave during drought and to assess the risk of human-wildlife conflict across species, regions and drought timescales.
From individuals to networks: The role of variation in plant-pollinator communities' responses to global change.
Crall JD, Gaiarsa MP
J Anim Ecol · 2026 Jun · PMID 42331731 · Publisher ↗
Plant-pollinator communities are critical for biodiversity, ecosystem function and human well-being. Yet our ability to predict divergent species responses to environmental change, the risk of abrupt collapse, or the pot...
Plant-pollinator communities are critical for biodiversity, ecosystem function and human well-being. Yet our ability to predict divergent species responses to environmental change, the risk of abrupt collapse, or the potential for recovery in plant-pollinator systems remains limited. Here, we argue that individual variation within species may play a critical but underappreciated role in shaping the sensitivity, robustness and resilience of animal pollinators and plant-pollinator communities. We explore processes by which individual variation may influence responses to perturbation, highlighting parallels with existing niche theory at the species level (e.g. the biodiversity-ecosystem function literature). We suggest that individual variation-as a key but distinct component of total intraspecific variation-may generate more gradual (rather than abrupt) responses to environmental stress than predictions based on species means in many cases, but that these effects will depend on how traits underlying performance, interaction frequency, stress sensitivity and pollination efficacy covary among individuals. Finally, we highlight critical knowledge gaps and open questions in the structure and dynamics of plant-pollinator interactions at the individual scale and conclude by outlining a roadmap for integrating individual variation into studies of plant-pollinator communities under global change.
Playing it safe at early life stages: Balancing energy allocations to maximize fitness under seasonal pathogen dynamics.
Colón-Piñeiro Z, Martin NW, Klee TJ … +5 more , Buchanan BL, St Mary CM, Acevedo MA, Burrowes PA, Longo AV
J Anim Ecol · 2026 Jun · PMID 42294992 · Publisher ↗
Immune responses are crucial to not only control within-host disease dynamics and potential negative outcomes to host health but also impose energetic trade-offs with growth and other physiological processes. Although th...
Immune responses are crucial to not only control within-host disease dynamics and potential negative outcomes to host health but also impose energetic trade-offs with growth and other physiological processes. Although these trade-offs play an important role in disease outcomes, we lack mathematical models that mechanistically describe how variations in energy investment and parental reproductive timing influence offspring survival under seasonal pathogen dynamics. Here, we determine the strategies (set of tactics-growth versus immune defence-over time) that maximize host fitness under persistent infections by implementing dynamic optimization state models. We modelled individual trajectories for 1 year and accounted for natural fluctuations in resource availability. We parameterized the model using field and experimental data from a well-studied host-pathogen system: the coqui frog (Eleutherodactylus coqui) and the amphibian chytrid fungus (Batrachochytrium dendrobatidis). This data from field monitoring and controlled experiments enable robust parameter estimation and subsequent validation using empirical data. Our models identified critical windows that maximize individual growth while limiting mortality under increased pathogen burden. Individuals generally chose growth but shifted to defence when approaching near-lethal infection levels. Seasonality in pathogen exposure and foraging success exacerbated growth-defence trade-offs, leading to delayed maturity and lower survival rates when frogs hatched under unfavourable conditions. Our simulations provide a mechanistic view that explains empirical results showing that periods of highest reproductive activity align with high-resource availability and low pathogen risk. Furthermore, our findings demonstrate that shifts in energy-allocation modulate infections and constrain fitness traits. Our results highlight the utility of dynamic state-variable models to examine how host fitness strategies impact early-life growth rates and recruitment (number of offspring reaching maturity). We provide detailed instructions that allow extending the application of this model to other systems. By adjusting parameter values using empirical data, this model approach can be applied to predict fitness under current and future conservation challenges, such as extreme droughts and pathogen outbreaks, and to identify the optimal time for releasing individuals in species reintroduction programmes.
When top-down is also bottom-up: Examining consumer-driven nutrient recycling in an arctic herbivore population.
Roy A, McFarland L, Steketee J … +2 more , Lavretzsky P, McLaren JR
J Anim Ecol · 2026 Jun · PMID 42283232 · Publisher ↗
Herbivore consumers represent important top-down and bottom-up forces in ecosystem regulation and an understanding of the zoogeochemical mechanisms of their influences is needed to better understand ecosystem function. T...
Herbivore consumers represent important top-down and bottom-up forces in ecosystem regulation and an understanding of the zoogeochemical mechanisms of their influences is needed to better understand ecosystem function. The consumer-driven nutrient recycling hypothesis (CNR) provides a framework for linking consumer populations and bottom-up regulation of ecosystem processes due to potential impacts of faecal nutrients on plant nutrient limitation. Here, we examine CNR by evaluating how changes in brown lemming density and foraging behaviour during different phases of their population cycle influence nutrient availability in an arctic tundra ecosystem. Our general objectives were to test whether CNR was supported in arctic tundra and whether CNR can be used to understand tundra ecosystem function. To achieve this, we (1) examined if faecal nutrient concentration and ratios varied between different phases of the lemming population cycle, (2) assessed whether lemming diets change seasonally, (3) examined whether faecal nutrients are affected by diet, (4) evaluated if changes in diet-caused changes in faecal quality influence plant nutrients and (5) examined the decomposition and nutrient loss from faeces. We found seasonal differences in faecal carbon (C) and phosphorus (P), with lower faecal C and P during late summer compared to mid-summer, but no differences in faecal N across seasons or changes in faecal nutrients across years. We also observed no differences in faecal nutrients (CNP) of lemmings fed different diets, but plants grown in faeces from an Eriophorum diet had greater biomass than that of plants grown with faeces from a Carex diet. Faeces persisted 1.5-4.4 years on the tundra depending on decomposition environment and while C and N were retained within decomposing faeces for several years, P was rapidly lost. Our data suggest tentative support for the CNR hypothesis in a tundra ecosystem; by providing limiting nutrients during the peak of the population cycle, faecal nutrients may influence ecosystem function and explain how the system recovers from cyclical disturbance regimes. Due to slow faecal decomposition, nutrients supplied during a population cycle peak may provide legacy effects on ecosystem function across multiple years.
Social organization and habitat use shape the gut microbiome of a marine fish.
Pons A, Aspillaga E, Catalán IA … +5 more , Viver T, Arlinghaus R, Martorell-Barceló M, Barcelo-Serra M, Alós J
J Anim Ecol · 2026 Jul · PMID 42271554 · Full text
The gut microbiome hosts diverse bacterial communities that significantly influence individual spatial behaviour in animal societies. However, this relationship remains understudied in marine fish due to the challenges a...
The gut microbiome hosts diverse bacterial communities that significantly influence individual spatial behaviour in animal societies. However, this relationship remains understudied in marine fish due to the challenges associated with measuring behavioural traits in free-living fish and simultaneously obtaining gut microbiome composition data. In this study, we conducted a field experiment to explore the relationship between space and habitat use, social organization, and gut microbiome composition in marine fish. We used a novel high-resolution acoustic telemetry system to collect 7930 one-day-long movement trajectories from 232 individuals of Xyrichtys novacula of the same population (153 females, 79 males) near the coastline of Mallorca, Spain. A subset of these individuals was recaptured to analyse the diversity of core and non-core gut microbiome, quantified using operational phylogenetic units (OPUs) based on 16S rRNA gene amplicons through Illumina sequencing. Individuals closer to Posidonia oceanica seagrass meadow had higher non-core microbiome diversity, especially larger individuals. Multivariate analysis showed no significant differences in microbiome composition across the tested variables (i.e. body size, territory size, degree, strength, distance to the seagrass meadow, and sex), but males showed a visually greater, but non-significant, variability in core microbiome composition. Core microbiome composition was weakly associated with social harem structure. These findings indicate that gut microbiome composition is primarily shaped by local habitat conditions, while social organization may contribute weakly and indirectly, pending further experimental validation.
Hotter, faster, sicker? Warming shifts the cost of infection from individuals to populations.
Butterworth NJ, Moore KJ, Hall MD
J Anim Ecol · 2026 Jun · PMID 42267638 · Publisher ↗
The thermal environment can profoundly modify the damage that pathogens cause to hosts. Yet while the interacting impacts of infection and temperature on individual life-history traits are well documented, how these effe...
The thermal environment can profoundly modify the damage that pathogens cause to hosts. Yet while the interacting impacts of infection and temperature on individual life-history traits are well documented, how these effects scale to demographic consequences across thermal gradients remains poorly understood. Using the Daphnia magna-Pasteuria ramosa system across a 10-30°C gradient, we tested whether virulence in individual-level life history metrics reliably reflects the consequences for predicted population growth rates. Our results reveal a stark mismatch between scales: the cost of infection on individual life-history traits (fecundity, body size, and lifespan) was maximised at low temperatures, whereas the impact on population growth rate was maximised at high temperatures and at the thermal optima of healthy hosts. These findings demonstrate that standard virulence metrics at the scale of individual life-history traits may underestimate demographic risk in warming environments. To reliably predict population persistence in the face of disease under a changing climate, it is important to account for the temperature-dependent scaling of pathogen virulence and host life-history to population growth rates.
Offshore wind farm avoidance by a discard-feeding seabird is independent of local fishing activity.
Kentie R, van Bemmelen RSA, Shamoun-Baranes J … +2 more , Stienen EWM, Fijn RC
J Anim Ecol · 2026 Jun · PMID 42260680 · Publisher ↗
Offshore wind farms are increasing rapidly in number and scale, presenting potential risks for seabirds. Some seabirds actively avoid offshore wind farms, whereas others are attracted to them. Both avoidance and attracti...
Offshore wind farms are increasing rapidly in number and scale, presenting potential risks for seabirds. Some seabirds actively avoid offshore wind farms, whereas others are attracted to them. Both avoidance and attraction can have detrimental effects, including habitat loss and increased collision mortality. Because commercial fishing is typically restricted within wind farm boundaries, apparent avoidance by discard-feeding species may reflect attraction to nearby fishing activities rather than actual wind farm avoidance Here we studied the temporal variation in avoidance and attraction of 58 GPS-tracked Lesser Black-backed Gulls (Larus fuscus) to both the offshore wind farm and fishing activity within the foraging range from their breeding colony. If apparent avoidance of offshore wind farms was caused by an attraction to nearby fisheries, we expected a lower selection strength of the offshore wind farm during weekdays when fishing activity is much higher compared to weekends. We used a step selection analysis to estimate relative selection strength including individual variability and tested if the selection strength for wind farms and fishing activity differed between the pre-breeding, breeding and post-breeding periods, between sexes, and between weekdays and weekends. At the population level, gulls avoided the offshore wind farm during most periods and selected areas with fishing activity compared to areas without. The selection strength of wind farms and attraction to fisheries varied substantially between individuals, with several males being attracted to the wind farm during the breeding and post-breeding period. Variation between individuals in avoidance of offshore wind farms varied most during the breeding period. The attraction to fishing activity did not differ between periods and sex. Fishing intensity was four times lower during the weekends than during weekdays. However, we found no support that gulls differed in wind farm avoidance between weekdays and weekends, suggesting that avoidance is not primarily driven by fishing exclusion within wind farms. This research contributes valuable empirical data to improve the biological realism of Collision Risk Models by demonstrating that individual variability in avoidance behaviour warrants the inclusion of behavioural heterogeneity in these models rather than assuming uniform population responses.
Assessment of large-scale spatial variation in age-specific survival and age at first breeding in a long-lived species.
Muller MH, Ketwaroo FR, Fiedler W … +3 more , Geiter O, Herrmann C, Schaub M
J Anim Ecol · 2026 Jul · PMID 42249665 · Full text
Age-dependent survival and age at first breeding are key demographic parameters that drive population dynamics. Although crucial for understanding population trends and informing region-specific conservation strategies,...
Age-dependent survival and age at first breeding are key demographic parameters that drive population dynamics. Although crucial for understanding population trends and informing region-specific conservation strategies, the large-scale spatial variability of these demographic parameters, as well as how temporal fluctuations are correlated across space (i.e. spatial synchrony), are poorly known. This is particularly the case in long-lived species characterised by complex, age-dependent life cycles. White storks (Ciconia ciconia) from Germany provide an opportunity to study spatial variation in age-dependent survival and age at first breeding as they are long-lived and extensively monitored through long-term ringing programmes across the whole country. The contrasting population trends observed between western (increase) and eastern Germany (slight decrease), between which migratory flyways differ, suggest substantial spatial variation in demographic parameters. We analysed ringing, resighting and recovery data of 92,251 individuals collected from 2000 to 2023 across Germany, using the federal states (Bundesländer) as spatial units. We fitted three spatial multistate capture-recapture-recovery models that differed in whether and how spatial autocorrelation among spatial units was incorporated. The spatial patterns of the demographic parameters were similar across the three fitted models, but the model that used flyway information for the structure of spatial autocorrelation performed best. Survival in all age classes was higher and age at first breeding lower in western than in eastern Germany, consistent with the respective population trends. Spatial variability in survival was higher in juveniles than in other age classes, and synchrony across space was found in juvenile survival, but not in the survival of older age classes. The developed models with alternative formulations of spatial autocorrelation were useful to assess the structure of spatial variation in survival and age at first breeding. Our results highlight substantial large-scale spatio-temporal variation in demographic parameters within a long-lived species, helping to explain spatial differences in population dynamics across the study area.
Snowmelt predicts earlier breeding across the latitudinal range of an Arctic nesting seabird, the Little Auk (Alle alle).
Syposz M, Varpe Ø, Descamps S … +9 more , Fort J, Grémillet D, Harding A, Jakubas D, Kidawa D, Skyllas N, Strøm H, Versluijs TSL, Wojczulanis-Jakubas K
J Anim Ecol · 2026 Jul · PMID 42233617 · Full text
Climate-driven temporal shifts in seasonal environments are altering some of the environmental cues that organisms use to time reproduction, potentially leading to trophic mismatches across ecosystems. In the Arctic, mar...
Climate-driven temporal shifts in seasonal environments are altering some of the environmental cues that organisms use to time reproduction, potentially leading to trophic mismatches across ecosystems. In the Arctic, marine predators must balance conditions at sea with local terrestrial constraints at breeding sites, yet the relative importance of these cues for breeding phenology remains unclear. We used a crevice-nesting High-Arctic planktivorous seabird, the Little Auk (Alle alle), as a model species. Drawing on a unique multi-year dataset from four colonies with distinct climatic regimes, we tested whether breeding onset tracks the timing of snowmelt at breeding sites, a key terrestrial cue determining nest accessibility. Snowmelt timing is closely linked with hatching date, with earlier snowmelt enabling earlier access to nesting crevices and advancing hatching across all sites. Importantly, we detected no significant directional temporal trend in snowmelt timing over the study period (2000-2024), suggesting that this relationship reflects interannual variability. Within years, later hatching was associated with reduced chick growth and survival across colonies. However, interannual variation in mean hatching date was linked to chick survival in only one colony, indicating spatial heterogeneity in demographic consequences of breeding phenology. Future projections indicate that snowmelt timing will advance where little auks breed, potentially advancing breeding timing. However, other ongoing changes-such as borealization of zooplankton communities and the loss of summer sea ice-may alter future fitness consequences of breeding timing. Our study highlights the role of the terrestrial environment in shaping the breeding timing of high-latitude marine birds.
Warming increases trophic cascade strength in an aquatic food chain.
Biagioli FP, Coblentz KE, Yang L … +2 more , Thilakarathne D, DeLong JP
J Anim Ecol · 2026 Jul · PMID 42227271 · Full text
Trophic cascades play a central role in shaping ecosystems, yet it is unclear how their strength responds to warming. Because species' demographics and trophic interaction strengths are temperature sensitive, climate cha...
Trophic cascades play a central role in shaping ecosystems, yet it is unclear how their strength responds to warming. Because species' demographics and trophic interaction strengths are temperature sensitive, climate change is expected to alter cascade strengths, with potentially widespread ecological consequences. We experimentally tested how temperature affects trophic cascade strength by manipulating the presence of the predator Hydra oligactis and tracking the abundances of its prey, Ceriodaphnia reticulata, and primary producer, Ankistrodesmus falcatus, across a temperature gradient. To uncover the mechanisms driving these changes, we complemented the experiment with mathematical models fit to the population dynamics, providing novel insight into why trophic cascade strength changes with warming. We predicted that warming would strengthen trophic cascades by increasing direct consumer-resource interaction strengths. Our results supported this prediction, and we also found that higher temperatures amplified transient population fluctuations, driven by the combined temperature dependence of nearly all the model parameters. Our findings show that climate warming can strengthen trophic cascades, destabilize population dynamics and magnify the ecological impacts of predator loss through complex, temperature-dependent changes in species interactions and demographics.
Asymmetric niche partitioning in large omnivores in response to anthropogenic disturbances within subarctic ecosystems.
Brown L, Mantyka-Pringle C, Potié J … +3 more , Savage P, Hornseth M, Fisher JT
J Anim Ecol · 2026 Jul · PMID 42220301 · Full text
Niche partitioning is an evolutionary process that allows the coexistence of multiple species in a landscape. However, human disturbance can interfere with this process. For instance, humans may displace competitors and...
Niche partitioning is an evolutionary process that allows the coexistence of multiple species in a landscape. However, human disturbance can interfere with this process. For instance, humans may displace competitors and favour species with a greater tolerance for disturbances. American black bears (Ursus americanus) and grizzly bears (U. arctos) are two large omnivores that share similar ecological niches, but that can also coexist by partitioning resources. Understanding the consequences of anthropogenic disturbance on niche partitioning in these two species is important to preserve biodiversity and ecosystem function. This importance is particularly relevant in landscapes located in subarctic biomes where resource availability is limited. In this study, we used data from wildlife cameras deployed at 194 sites in central Yukon during 2020-2023 to determine whether anthropogenic disturbances facilitated, or disrupted, spatiotemporal niche partitioning in American black bears and grizzly bears. Kernel density functions revealed that grizzly bears modified their diel activity pattern in the higher-disturbance landscape during the afternoon, presumably to avoid interactions with humans. This new peak coincidentally promoted temporal niche partitioning with black bears, whose activity pattern remained static across the gradient of disturbance. The bear species spatially segregate, but anthropogenic disturbances had a much stronger effect on grizzly bear occurrences compared to black bears, signalling an asymmetric response. Anthropogenic disturbances constrained grizzly bears to the lower-disturbance landscape. Black bears could take advantage of reduced competition and partially fill the spatiotemporal niche of grizzly bears, but our results did not show that black bears concentrated their activity in areas avoided by grizzly bears. The displacement of grizzly bears may lead to shifts in prey populations or vegetation communities, with unknown consequences for ecosystem structure.
Deep blueprint: A literature review and guide to automated image classification for ecologists.
Game CA, Piechaud N, Howell KL
J Anim Ecol · 2026 Jun · PMID 42220300 · Publisher ↗
Deep learning (DL) is a powerful tool to extract ecological information from large image datasets efficiently and consistently. However, applying these methods remains challenging, due in part to the complexity of DL wor...
Deep learning (DL) is a powerful tool to extract ecological information from large image datasets efficiently and consistently. However, applying these methods remains challenging, due in part to the complexity of DL workflows and the dynamic nature of available tools. To address this, we created a practical guide and review, focused on one of the fundamental tasks in automated image analysis: image classification. Our approach integrates commonly used software and highlights key steps-from image acquisition to annotated, model-ready datasets, to training, evaluation and deployment. It is modular and supported by a flexible code base (in Python, with R alternatives where possible) and Graphical User Interfaces (GUIs), enabling adaptation to different models and ecological objectives. The goal is to empower ecologists to confidently incorporate computer vision into their research. We illustrate this approach, using an open-source ROV dataset from the Norwegian Sea, featuring deep-sea biotopes defined by multivariate clusters of depth, substrate type, and associated species. To balance accessibility for users alongside performance, we focused on CNN models from the Ultralytics ML Platform (YOLO V.8 and V.11), comparing the full suite of architectures that range in complexity and efficiency. Cross-validation revealed high overall performances and that larger, more complex models are not always superior, with YOLO V.8m best (accuracy and macro-averaged performance metrics = ~0.97-0.98). Notably, high performances were achieved despite labels being based on both visual and external environmental predictors, suggesting visual features alone were sufficient for classification in this dataset. We highlight that the decision to deploy a model must be made in light of the study's objectives, with domain-based reasoning and experience guiding every stage of implementation. This work offers a practical blueprint for implementing DL in ecological research, promoting broader adoption and supporting reproducibility and more efficient, standardised, and sustainable monitoring; in this case of deep-sea biotopes, which is essential for marine spatial planning.
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