Journal of Animal Ecology

BackgroundEnvironmental conditions shape the evolutionary trajectories of RNA viruses, yet little is known about how complex physical stressors such as microgravity influence host-virus interactions and viral evolution. Here, we investigated the short-term evolutionary consequences of simulated microgravity on the Caenorhabditis elegans - Orsay virus (OrV) system. MethodsOrV was subjected to six serial passages in hosts acclimated to low-shear modeled microgravity, with parallel evolution under standard-gravity. Evolutionary outcomes were evaluated using virulence, transmission, and replication traits, all measured under standard-gravity conditions. ResultsViral load fluctuated across passages in both environments, with lower mean accumulation in microgravity-evolved lineages. After evolution, we detected no significant changes in virulence. Transmission increased in standard-gravity lineages but not in microgravity-evolved ones, while viral replication decreased in all lineages, with a stronger decline in those evolved under microgravity. However, the magnitude of phenotypic changes was generally modest. DiscussionThese results indicate that evolution under microgravity can alter viral phenotypic trajectories over short timescales. However, because all traits were assayed under standard-gravity conditions, we cannot directly assess local adaptation to microgravity, and the observed differences may reflect environment-specific trade-offs rather than reduced fitness per se. Furthermore, the limited number of passages and the modest magnitude of phenotypic change suggest that evolutionary responses may still be in an early stage. ConclusionOverall, our findings provide initial evidence that simulated microgravity can influence the evolutionary dynamics of an RNA virus, while highlighting the need for reciprocal fitness assays and longer-term experiments to fully characterize adaptation to altered gravitational environments.

Ocean warming is altering abiotic environments and biotic interactions experienced by marine organisms, where sensitive early developmental windows occur in biologically complex seawater communities. The impact of these interactions on developmental processes and fitness in hosts is not well understood, but likely contingent on the establishment of a host-associated microbiome. Here, we hypothesize that temperature and microbial exposure during embryogenesis influence larval microbiome assembly and host morphology. Strongylocentrotus purpuratus embryos were raised in low microbial richness (LMR) or high microbial richness (HMR) seawater at ambient (14 {degrees}C) or elevated (18 {degrees}C) temperature, then collected at 2, 4, and 6 days post-fertilization (dpf) following multiple feedings. Higher microbial diversity was observed in larvae that developed in HMR seawater when compared to LMR. Differences in relative abundances of dominant microbial families between seawater and larvae suggest some degree of host selectivity in microbiome assembly. Temperature did not strongly alter microbiome composition, but both temperature and microbial condition led to differences in larval morphology by 6 dpf, potentially due to enrichment of microbes with chemoheterotrophic functions. By linking how temperature and microbial communities interact with host development, we contribute novel insights into how early-life environmental conditions impact holobiont formation and morphology. One sentence summaryEarly developmental temperature and microbial conditions shape larval microbiome establishment and morphology.

Winter can affect animal population dynamics by limiting resource availability and increasing energetic costs of movement caused by deep snow. Given the rapid alteration of snowpack properties due to climate change, quantifying how snow characteristics influence reproduction and physical condition is critical. We evaluated how snow cover duration, depth, and density affect spring body mass, reproduction probability, and subsequent autumn body mass of bighorn sheep (Ovis canadensis) using 45 years of individual-based data at Ram Mountain, Alberta, Canada, along with historical snow records reconstructed via the SNOWPACK model. Using Bayesian structural equation modeling, we quantified the direct and indirect effects of snow across different sex and age classes. Long and deep snow covers reduced spring body mass across all demographic groups, with yearlings, especially males, losing up to 0.12 kg per additional cm of snow depth. Harsh snow conditions reduced the probability of reproduction for adult females and generated a compensatory indirect effect on mass by avoiding the energetic costs of reproduction. In contrast, yearlings showed no compensatory responses and entered the following autumn in poor condition (up to 14% lighter for males and 8% for females following the deepest snow years). The impact of snow density on autumn mass of adult males was density-dependent, shifting from beneficial at low density (+0.09 kg per kg/m3) to detrimental at high density (-0.04 kg per kg/m3). The effects of snow conditions generate persistent, context-dependent carry-over effects across seasons. Our study suggests that distinct demographic groups rely on different mechanisms to cope with environmental constraints, highlighting complex, time-lagged consequences of changing winter climate on alpine herbivore populations.

O_LIAgricultural intensification can support the expansion of introduced species which are highly adapted to human-modified landscapes, but the mechanisms by which this occurs are often unclear. C_LIO_LIHere we investigate the spatial ecology of a rapidly expanding introduced bumble bee (Bombus impatiens) and a native congener (B. mixtus) in agricultural landscapes of southwestern British Columbia, Canada. We used microsatellite genotyping and spatially explicit capture-recapture models to compare the foraging distance of the two species, and fitted hierarchical models to compare their abundance, behaviour (nest searching vs foraging), and lineage survival as a function of landscape composition and configuration. C_LIO_LIWe found that B. impatiens had a broader foraging range than B. mixtus, and that its colony/worker abundance were positively associated with the surrounding area of residential gardens, but decreased relative to B. mixtus abundance in response to increasing seminatural area. In contrast, B. mixtus colony abundance decreased in landscapes with a greater area of intensively managed berry crops. C_LIO_LIWe observed fewer B. impatiens queens per survey in landscapes with more low-disturbance landcover, and hypothesize space use of this species could be shaped by concentration on potential nesting habitat. Consistent with this observation, nest searching behaviour was more common for B. impatiens queens, while B. mixtus queens were primarily observed foraging, suggesting these two species derive different value from agricultural landscapes during colony establishment. C_LIO_LIFinally, we found that the rate of lineage re-capture between 2022 colonies and 2023 spring queens was nearly 10-fold higher for B. impatiens than for B. mixtus, indicating a greater capacity of the introduced species to complete its life cycle in agro-natural landscape mosaics. C_LIO_LIOur results suggest that differences in spatial ecology may contribute to the differential success of these two species in human-modified landscapes, and provide insight into the mechanisms by which land-use change shapes community composition. C_LI O_FIG O_LINKSMALLFIG WIDTH=184 HEIGHT=200 SRC="FIGDIR/small/723627v1_ufig1.gif" ALT="Figure 1"> View larger version (62K): org.highwire.dtl.DTLVardef@1e72eacorg.highwire.dtl.DTLVardef@a958a0org.highwire.dtl.DTLVardef@1f970b6org.highwire.dtl.DTLVardef@156f522_HPS_FORMAT_FIGEXP M_FIG C_FIG Graphical abstract. Coloured diagrams of B. mixtus and B. impatiens are credited to Elaine Evans and the Xerces Society, with permission.

AimHome range size is a fundamental aspect of animal spatial ecology, and understanding the factors that shape it is important for conservation purposes. Several hypotheses, based on energy needs or competition, assume that home range size negatively correlates with population density. However, this pattern has been little investigated on a global scale, and it remains unclear whether it would stand at both intra- and interspecific levels. To fill this gap, we conducted a global exploration of this relationship at the level of an animal family. Location: Global. Time period: Contemporary. Major taxa studied: Wild Felidae. MethodsIndividual home range size records (n = 1022) and population density estimates (n = 1061) were retrieved from the literature for 23 felid species across the world. We first investigated the interspecific relationship by modelling the median home range size of a species as a function of its median population density. To study the intraspecific relationship, we spatially merged data points based on their spatial or temporal proximity. We then applied a mixed-effects linear model using species as a random factor. ResultsWe found that home range size was negatively associated with population density, at both interspecific (-1.323 {+/-} 0.180, p < 0.001) and intraspecific levels (-0.569 {+/-} 0.201 to - 0.537 {+/-} 0.201 depending on the merging approach, p < 0.01). Landscape features were also predictors of home range size, without confounding the effect of population density. Main conclusionsSeveral processes likely govern the relationship between home range size and population density: differences in body mass between species may drive the interspecific relationship, whereas the intraspecific pattern is probably explained by conspecific competition. Although more research is needed to quantify their relative contribution, our study highlights a worldwide ecological pattern that exists at multiple biological levels in the wild.

A hosts diet can alter the course of parasite infection. This is especially true of trophic parasites, which a host acquires through feeding. While a large body of work attests to the role of diet in the spread of disease within-hosts, diet can also impact host density and encounter rate with parasites, both of which are expected to modify disease dynamics. When parasites are acquired through feeding, epidemics may be larger and more severe on high-quality diets if these diets support a higher density of hosts that feed more and thus ingest more parasites. Alternately, epidemics may be more severe on low-quality diets if malnourishment decreases hosts ability to resist disease. To differentiate these hypothesized effects of diet on disease, we quantified individual infections and epidemic dynamics for the natural microsporidian parasite Nematocida ironsii infecting its nematode host Caenorhabditis elegans. We measured feeding rate, parasite transmission, and host fitness across three bacterial diets that vary in quality and elicit distinct feeding behaviors in C. elegans. We found that low-quality diets reduced feeding rate, which corresponded to reduced acquisition of parasite spores. However, these diet-mediated differences in parasite acquisition did not directly map onto fitness consequences: hosts eating the poor-quality diet had similar reductions in fitness to those on higher quality diets. During epidemics, a combination of increased parasite acquisition and higher population growth rates resulted in higher parasite abundance for hosts on high-quality diets. Our work underscores the importance of considering both individual- and population-level impacts acting in concert to determine how diet affects the spread of infectious disease.

Interactions between cleaner fish Labroides dimidiatus and client fish, from which cleaners remove ectoparasites and mucus, represent a textbook example of mutualism involving sophisticated strategic decision-making. However, cleaners must also face intraspecific social challenges within a size-based hierarchy, where the largest females may eventually change sex and become males with higher reproductive rates. Following 540 individuals over 11 months, we found that, contrary to expectations, slow-growing females spent more time cleaning and cheated more frequently, without causing more negative client responses than fast-growing females did. Instead, variation in growth was best explained by social factors: fast-growing individuals experienced reduced social control, while slow growers spent more time in proximity to dominant individuals. As there was no evidence that spawning activity affected growth patterns, it appears that fast growth as a viable strategy for becoming a male largely depends on the lack of control by dominants.

Changing climates are reshaping animal populations, but our understanding of how demographic trends are shaped by individual responses to local environmental conditions is often limited to long-term studies with restricted spatial scales. Increasing evidence suggests that climatic extremes exert differential selection pressures across environments, often leading to nonstationary biological responses among populations. Participatory science (i.e. citizen science) observations can detect this variation at large geographic scales, but analyses of these data often lack insight into the individual-level responses that are required to explain the origins of such variation. Here we present a new research framework that uses long-term data to validate, then inform analyses of participatory science data to measure reproductive responses to environmental variation across large geographic scales. We use this approach to investigate how reproduction in a montane-adapted songbird, the mountain chickadee (Poecile gambeli), varies across elevations and latitudes in response to extreme scarcity and extreme accumulation of snow throughout the Sierra Nevada Mountains in North America. Chickadee reproduction in lower and higher elevation populations was often differentially impacted by drought and deluge snowfall extremes, but these relationships varied across latitudes. Reproductive performance in the northern Sierra Nevada was negatively affected by snow deluge conditions at high elevations, whereas snow drought conditions reduced reproductive output at low elevations. These relationships changed in the central Sierras where drought conditions negatively impacted both elevations, but deluge conditions improved reproductive performance at both low and high elevations. Reproduction in the southern Sierra Nevada was less affected by spring snow levels, likely due to the lower snow accumulation and earlier snowmelt in this region. These results emphasize the power of long-term studies to inform and interpret participatory science data in order to better understand how animal responses to environmental extremes vary across large geographic scales.

Wildlife vaccination could become a powerful strategy to mitigate disease-induced biodiversity losses, yet many vaccines for wildlife diseases provide only limited protection. Notably, tools to control the fungal pathogen Batrachochytrium dendrobatidis (Bd) are urgently needed for amphibian conservation. Laboratory experiments have demonstrated that prophylactic exposure to Bd metabolites increases host resistance, significantly reducing infection intensity in amphibians subsequently challenged with live Bd. Because Bd metabolites are non-infectious and applied topically, this treatment has potential to be administered to waterbodies to vaccinate and protect amphibians. We developed an agent-based model that indicated imperfect vaccination could reduce or amplify Bd infections at the population level, depending on degree of enhanced resistance or tolerance. Utilizing a Before-After-Control-Impact design with ten years of data, we conducted an ecosystem-level trial where we applied low levels of Bd metabolites or a sham control treatment to ponds in California and subsequently quantified Bd prevalence and infection intensity in metamorphosing Pacific chorus frogs (Pseudacris regilla). Unexpectedly, infection intensity was significantly greater in treated ponds relative to control ponds following metabolite addition. Additional model simulations indicated that this could occur via two mechanisms: (1) if treatment greatly increased tolerance alone or in combination with smaller increases in resistance, or (2) if a deleterious environmental interaction caused the treatment to increase susceptibility, rather than promote resistance. Future research is needed to determine whether tolerance or environmental factors drove heightened Bd infection intensities in this field trial to identify contexts in which this treatment can be used as a conservation tool. Significance statementAlthough wildlife vaccination is increasingly explored as a strategy to mitigate disease-induced population declines, many available vaccines provide limited protection, requiring careful consideration to design successful conservation campaigns. Here, we use both an eco-epidemiological model and field manipulation experiment to assess the effectiveness of an imperfect prophylactic treatment (akin to a prototype vaccine) for chytridiomycosis, a disease implicated in the massive decline of amphibian biodiversity worldwide. We unexpectedly found that prophylaxis-treated ponds had higher pathogen loads relative to control populations and models suggest this could result from enhanced tolerance or an adverse environmental interaction.

BackgroundWintering migratory birds must balance energetic requirements, resource availability, and disturbance in increasingly human-modified landscapes. However, individual-level variability in daily movement and winter space use remains poorly understood in South Asian populations of the common crane. We investigated how seasonal dynamics, landscape composition, and individual differences structure winter movement ecology in a semi-arid agro-wetland system in western India. MethodsWe analysed high-resolution GPS telemetry data from multiple tagged cranes tracked across three consecutive winters. Daily movement distances were modelled using mixed-effects approaches to partition variance within and among individuals and among winters. Daily movement trajectories were evaluated using non-linear temporal terms. Landscape predictors, including cropland proportion, built-up area, and habitat heterogeneity, were incorporated to assess environmental drivers. Winter range distributions were estimated using autocorrelation-informed kernel density estimation within a continuous-time movement modelling framework. ResultsMost variation in daily movement occurred within individuals rather than among them, indicating strong behavioural flexibility. Interannual differences explained substantial variance, suggesting sensitivity to changing environmental conditions. Daily movement distance followed a non-linear seasonal pattern consistent with shifts in the profitability of agricultural resources over winter. Cropland proportion and landscape evenness were negatively associated with movement distance, whereas a high proportion of built-up areas increased daily movement distance, reflecting a trade-off between resource concentration and anthropogenic disturbance. Winter range distribution size varied markedly both within individuals across years and among individuals within seasons. ConclusionWinter movement and space use in common cranes are predominantly context-dependent and environmentally driven. Seasonal dynamics, agricultural landscapes, and human disturbance jointly structure movement patterns, with limited but consistent individual differences. Multi-year, individual-based telemetry provides a comprehensive understanding of winter spatial strategies in dynamic semi-arid agro-wetland systems.

AimHuman land-use change contributes to biodiversity declines, but also creates new niches that facilitate novel biotic interactions. These interactions can reshape ecological communities and ecosystem function, yet remain poorly understood. Swiftlets and swallows in Southeast Asia present a classic example: coexistence is facilitated by fine-scale diet partitioning, with population sizes historically limited by available nesting substrates. However, several species now nest on manmade structures, particularly "nest farms" built to harvest edible swiftlet nests. We evaluated whether land-use change, especially the spread of nest farms, is leading to breakdowns in niche partitioning and increased competition among six sympatric swiftlets and swallows. LocationNorthern Borneo MethodsWe calculated geographic niche overlap using species distribution models (SDMs) with different environmental predictors, hypothesizing greater overlap when land-use variables were included. We then implemented joint species distribution models (JSDMs) to partition shared environmental responses from potential biotic interactions, predicting that competition would emerge as negative residual correlations. We used sightings from citizen-science datasets and structured surveys to evaluate the influence of climate, land-use, nest farms, morphology, and foraging behavior on species occurrences. ResultsSDMs that included land-use variables showed high niche overlap, suggesting that human activity homogenizes niches. The optimal JSDM, based on structured survey data, identified distance to nest farms as the strongest predictor of occurrence for all species, with species showing both positive and negative responses. Morphology and behavior had small effects, and residual correlations were weak, indicating limited unexplained biotic interactions. Main conclusionsHuman activity, through the creation of artificial nesting sites, broadly drives co-occurrence of swallows and swiftlets across our study region. These effects appear to operate primarily through environmental filtering rather than direct competition. Our findings reveal substantial and complex impacts of land-use change and anthropogenic nest sites on the distribution and composition of aerial insectivore communities.

Cities are characterized by elevated temperatures, increased pollution, and high-density human populations which often are accompanied by changes in available resources, like food. These shifts have the potential to drive phenotypic divergence in urban wildlife. Functional morphological traits, like body size, can mediate interactions between wildlife and habitat and are closely tied to life history and fitness. While examples of functional morphological variation associated with urbanization are increasing, variation in such traits as a response to urbanization remains unexplored for most taxa. Here, we investigated morphological divergence between urban and rural populations of house mice (Mus musculus domesticus). House mice are globally distributed in diverse habitats and are a model system with a wealth of phenotypic data, making them useful for the study of the impacts of urbanization on morphology. Using a paired replicate design, we sampled urban and rural populations in three distinct metropolitan regions in the eastern United States. We found that body size was smaller in urban populations. Using 3D geometric morphometrics, we also analyzed variation in cranial shape across habitats. Differences in cranial shape were largely allometric, that is, driven by differences in body size. However, we also uncovered evidence of cranial shape variation between habitats not explained by size. In contrast, we did not find evidence for habitat-driven differences in cranial capacity independent of size. Overall, our results suggest a key role for body size in mediating morphological responses to urbanization and highlight the potential of house mice as a globally-distributed model for urbanization.

Prolonged association between mothers and their offspring is common in ungulates, with the level of maternal investment likely to play a central role in shaping this trait. Here we examined patterns of association between mothers and offspring over time, the apparent benefits of association to offspring, and costs to mothers. We analyzed 40 years worth of census data from an individually-monitored, food-limited population of red deer (Cervus elaphus) on the Isle of Rum, Scotland. Starting from birth, female calves associated more frequently with their mothers than male calves in their first year. Calves also associated less with their mothers if the mother did not conceive a new calf. Association frequency decreased with mothers age and population density, and survival over the first year was not related to mother-calf association. Yearlings, now in their second year, were more often associated with their mothers if they were female, if there was no subsequent calf (or the subsequent calf died as a neonate), and if they were still being suckled. Increased association between mothers and yearlings was associated with increased survival to adulthood at 28 months, but suckling a yearling did not improve its probability of survival. For individuals that reached maturity, increased association in the yearling year was associated with slightly shorter adult life spans. The level of association between a calf and mother was not associated with the mothers immediate survival or fecundity. Our findings suggest that juveniles born to poor-condition mothers benefit from prolonged association through improved yearling survival.

Helminths are widespread parasites that can modulate host immunity, potentially increasing susceptibility to viral infections. However, evidence for these effects varies across systems and environments, and links between laboratory and wild populations remain unclear. We developed a tractable system using wood mice, Heligmosomoides spp. nematodes, and wood mouse herpes virus (WMHV) to bridge this gap. Combining laboratory and field experiments with population modelling, we examined how helminth infection, anthelmintic treatment and diet affect viral dynamics. Across lab and field data, helminth infection consistently increased WMHV risk, with stronger effects at higher worm burdens. Field results showed that anthelmintic treatment reduced viral infection, and laboratory experiments showed that improved nutrition mitigates helminth-induced increases in viral susceptibility. Our population-level modelling suggested that helminth burden-dependent facilitation can generate nonlinear effects on viral spread, dependent on helminth virulence. Our findings highlight the potential importance of helminths as facilitators of viral infections, and suggest that anthelmintic treatment may provide indirect benefits for viral control. We also show the value of integrating lab and field approaches on the same (or closely related) species, in particular the potential offered by the wood mouse - Heligmosomoides - WMHV system, to understand the drivers and consequences of host-helminth-viral interactions.

ContextAnimals balance resource acquisition with risk mitigation. These trade-offs are rarely uniform, being mediated by spatial scale, demographic traits, and environmental constraints. Understanding these divergent spatial behaviors is critical for management across human-dominated landscapes. ObjectivesWe investigated how sexual dimorphism and ontogeny interact with landscape structure to influence scale-dependent resource selection. Specifically, we sought to determine how these demographic factors mediate spatial trade-offs between optimal foraging habitats, top-down intraguild predation risk, and bottom-up severe winter weather. MethodsWe examined the spatial ecology of a solitary carnivore, the bobcat (Lynx rufus), across a heterogeneous, human-modified landscape in northern Minnesota, USA. Using spatial data derived from harvested adult and juvenile individuals, we evaluated multi-scale selection relative to land cover, structural ecotones, intraguild predator activity, and winter severity. ResultsHabitat selection was scale-dependent and partitioned demographically. Whereas bobcats universally selected for ecotones and avoided homogeneous open habitats at fine scales, responses to other features diverged by sex and age. Females actively avoided areas with high coyote activity and freezing temperatures; males exhibited high risk tolerance, apparently indifferent to coyote activity and tolerant of freezing temperatures. We identified a distinct ontogenetic spatial shift among females. Subordinate juveniles were competitively excluded from optimal natural ecotones, forcing them into riskier, anthropogenic agricultural edges. In contrast, adult females optimized foraging opportunities by selecting productive ecotones at the intersection of woody vegetation and semi-natural grasslands. ConclusionsOur findings demonstrate that habitat selection is not a static species-level trait, but instead a dynamic process resulting from the interaction between ontogeny, sex, and landscape heterogeneity. The reliance of vulnerable demographic groups on marginal or anthropogenic habitats highlights how human land-use changes can inadvertently produce ecological winners and losers within the same species. Consequently, landscape management and conservation planning for solitary carnivores must shift from broad, population-wide habitat prescriptions to strategies that explicitly accommodate the divergent spatial requirements of specific demographic cohorts.

O_LIThe frequency and intensity of heat events is increasing across marine and terrestrial ecosystems. Within the same ecological community, the relative exposure and sensitivity to heat stress may vary considerably among interacting species, like predators and prey. This can be especially true for species that interact at the aquatic-terrestrial interface, as well as for interactions between primarily nocturnal and diurnal species, making it difficult to predict how such communities will respond to habitat warming. C_LIO_LIThermal limit metrics such as CTmax are often assumed to equate with ecological death because such temperatures impair behavioral activity and/or physiological functioning. Prey that are diurnally active can be more frequently exposed to temperatures that approach CTmax compared to their nocturnal predators, which may use thermal refuges during the day. Yet the impacts of daytime heat exposure on nighttime predation risk remain unknown. C_LIO_LIHere, we compared the thermal environment, performance, and heat tolerance between the predatory blue crab, Callinectus sapidus and one of its prey species, the mangrove periwinkle Littoraria anguilifera in a tropical mangrove ecosystem. We examined how exposing prey to heat stress at and below their CTmax affected their capacity to avoid predation in the field at night when predation risk is highest. C_LIO_LIWe found that acute exposure to temperatures near CTmax during the day increased the prey species susceptibility to predation during recovery at night. Although both interacting predator and prey have high thermal tolerance, prey are exposed to conditions that already reach CTmax, suggesting that current extremes in temperatures may already be influencing vulnerability to predation in this ecosystem. C_LIO_LIOur results suggest that differential exposure to sublethal heat stress in diurnal prey relative to their predator, along with the subsequent impact of these exposures on predation risk, will play a role in shaping these interacting as climate warms. C_LI

BackgroundThe Andean bear (Tremarctos ornatus), South Americas only ursid, is one of the worlds most elusive large mammals, making movement data collection exceptionally rare. Addressing this gap, we present the largest telemetry dataset ever assembled, spanning 19 individuals tracked across three Ecuadorian National Parks over two decades, paired with a novel analytical approach. MethodsWe integrated Continuous-Time Movement Models (CTMM), Auto-correlated Kernel Density Estimators (AKDEs), Hidden Markov Models (HMM) and a diel niche theoretical framework to mitigate biases previously unaccounted for the species in telemetry studies. Fine-scale AKDEs and non-linear movement metrics were calculated to understand seasonal space use and movement behaviors. Speed and diffusion from CTMM and behavioral states from HMM were modelled with environmental covariates to investigate which conditions shape diel and seasonal activity. ResultsPopulation mean home range was 138.2 km2 (95% Confidence Intervals 78.7-225.5), with males (239.8 km2; 182.8-307.5), significantly exceeding females (58.5 km2; 35.5-90.3). Notably, three females exhibited ranges comparable to some males. Weekly and monthly AKDEs uncovered cyclic home range dynamics potentially driven by resource availability, with contractions around corn harvests, mortino and achupalla fruiting, and expansions during paramo transitions. Decoupling speed from diffusion rates showed region-specific behaviors: intensive patch exploitation in Llanganates, broad exploratory ranging in Cayambe-Coca, and suppressed female locomotion in Cotacachi-Cayapas. Statistical analyses identified temperature as a key diel modulator and precipitation as the seasonal driver. Foraging probability increased between 2:00-6:00, large displacements between 7:00-14:00, and nocturnal movement rose significantly under colder conditions. Across diel hypothesis frameworks, bears were classified as cathemeral rather than strictly diurnal, corroborated by camera-trap records from Colombia, Ecuador, and Peru. ConclusionsWe propose a cathemeral diel phenotype that responds to thermal fluctuations and situates Andean bears within a broader ursid context of thermoregulatory niche plasticity. This dataset reveals unprecedented resolution of regional and sex specific behaviors that will facilitate and accelerate comparative studies in rapidly changing Andean landscapes. By releasing this long-term dataset as an open resource, we provide a foundation for climate-resilient conservation strategies. More broadly, we advocate for data democratization and invite collaboration.

Elucidating how habitat degradation facilitates extinction is critical for effective conservation efforts. Here, we propose integrating physiologically-structured population models into stochastic population viability analyses to assess how differing consequences of habitat degradation interact to drive extinction dynamics in a focal population. Using the isolated spectacled caiman Caiman crocodilus population/ecomorph from the Apaporis River as a case study, we find that threatening the resource base, which individuals increasingly rely upon, to outgrow vulnerable size ranges and mature accelerates extinction. We also found that when habitat degradation impacts both the primary adult and juvenile resource bases, this can have marked synergistic effects on threatening population viability. By contrast, destroying nesting sites has only a small effect on accelerating the impact of deteriorating prey availability. Through integrating community-level feedback between habitat degradation/change and population dynamics/structure, our approach provides a comparative framework for assessing the relative importance of distinct mechanisms through which habitat degradation ultimately drives extinction risk.

Within species, individuals of the same age can differ in size. Previously, parental genetics, nutrition, space, and social interactions have been suggested to explain different growth rates. However, direct effects of larger individuals on the physiology and growth of smaller individuals are poorly understood. In this study, we investigated how larger individuals of the marine worm Platynereis dumerilii can impact the growth of smaller conspecifics. Comparing growth distributions in communally and individually reared worms, we show that larger worms suppress the growth of smaller ones. Furthermore, we were able to demonstrate that this suppression is chemically mediated. The chemical cue does not originate from faeces but is water soluble, stable for several days and smaller than 3 kDa. Our findings highlight the importance of non-reproduction related chemical signalling, showing evidence that dominant individuals can chemically suppress the growth of their conspecifics. This study provides new insights into how hierarchy can be established and maintained in a population and is particularly relevant for the growing community studying this model species.

Urban pollinator gardens can provide refugia and support diverse populations of native bees amid threats from habitat destruction, pesticides, and potential ecological pressures from the introduced honey bee (Apis mellifera (Linnaeus, 1748)). The University of California, Berkeley, maintained a native bee garden at the Oxford Tract research facility to study the biodiversity, phenology, and foraging habits of urban bees from 2003 to 2009. That garden was decommissioned, and a new garden was re-established in 2019. Using diversity observations from the early 2000s garden and non-lethal sampling techniques, we characterized plant-pollinator interactions between flowers and urban bees in the newer bee garden with a bipartite interaction network. Across 12 flower species, we observed two non-native pollinators, the honey bee (A. mellifera) and the alfalfa leafcutter (Megachile rotundata (Fabricius, 1793)), along with at least ten native bee species across three families (Apidae, Halictidae, Megachilidae). We found that, despite the garden being created for native bees, honey bees accounted for 84% of all pollination interactions. The most abundant native bees were sweat bees (Family: Halictidae). Generalist interactions dominated the network, as both honey and sweat bees foraged on most available flowers. Honey bees showed a significant positive correlation with floral abundance, visiting flowers with the highest number of inflorescences, whereas native bees did not show this preference. These results indicate that native bee garden stewardship could benefit from greater floral diversity, while avoiding the dominance of any single species with high floral abundance, thereby reducing the likelihood of direct competition with honey bees.