Animal Conservation

Natural history collections underpin our understanding of species distributions, yet some historical records remain embedded in modern avifaunal checklists despite limited documentation and no independent verification. One such case concerns the Dusky Parrot Pionus fuscus in Colombia: although reported from specimens collected by Melbourne A. Carriker Jr. in 1942 in the Serrania de Perija, the species has not been observed in the country for nearly eight decades yet continues to be included in national checklists and conservation assessments. We reassessed the validity of this record by applying a multi-evidence framework integrating historic archival reconstruction, specimen-based morphological comparisons, climatic niche analyses, biogeographic limit assessment and contemporary survey-effort data. Historical documentation and morphological evidence based on high-resolution specimen images and associated curatorial records demonstrate that the Carriker specimens correspond to Pionus chalcopterus, not P. fuscus. Climatic niche analyses reveal minimal environmental overlap between P. chalcopterus and P. fuscus, and place the Perija locality within the climatic niche of P. chalcopterus, while regional biogeography and extensive modern birdwatching coverage provide no support for the occurrence of P. fuscus in Perija. Together, these concordant lines of evidence demonstrate that P. fuscus does not occur in Colombia. Our findings support its removal from national bird lists and conservation assessments and highlight how integrated, multi-evidence reassessments of historical records strengthen ornithological baselines, improve biogeographic inference and ensure that conservation priorities rest on verifiable evidence.

Understanding behavioral differences between non-native and closely related endangered species could be important to aid conservation management. In volume 169 of Zoology, Bels et al. (2025) reported on their comparison of display-action-patterns (DAP) between native Iguana delicatissima and non-native iguanas present on islands of the Guadeloupe Archipelago in the Caribbean Lesser Antilles. Here, we address conceptual and methodological concerns about their work and reanalyze their data given our proposed corrections, primarily a literature-informed adjustment of their "species" category. We additionally utilize online videos from South American mainland I. iguana populations, from where the non-native iguanas in the Guadeloupe Archipelago originate, to better understand the different DAPs between native and non-native iguanas in the Guadeloupe Archipelago. Significant differences in DAP characteristics among "species" categories (native I. delicatissima, non-native iguanas, and hybrids) show that Bels et al. (2025) oversimplified their data analyses by merging all non-native populations into one group. This result indicates the presence of behavioral variation among subpopulations within widely hybridizing iguanid populations, which has been poorly studied. Additionally, videos from mainland populations across two major mitochondrial clades of Iguana iguana show that non-native iguanas on Guadeloupe retained DAP characteristics of those populations from which they originate. We discuss these findings in light of the proposed hypotheses put forward by Bels et al. (2025), of which two can be excluded. Overall, our reanalysis shows that studies focusing on characteristics within settings of complex hybridization in diverse species should acknowledge this complexity.

Sleeping and feeding are crucial for survival of any animal. In case of large predators, knowing where these activities occur can help us understand their behavioural adaptations for coexisting with people and could help mitigating human-carnivore conflicts. Leopard (Panthera pardus) is an elusive and highly adaptable large felid that mostly lives outside protected areas and can survive also in close proximity to humans. However, most leopard research in Africa has been conducted in protected areas and we poorly understand leopards habitat selection while resting and hunting. To shed light on their coexistence with humans, we investigated habitat features influencing leopard selection of resting and kill sites on farmlands in central Namibia, using generalized linear mixed models (GLMM) under a use-availability study design and blinded field-sampling. Leopards primarily selected resting sites that were located in mountainous, steep, rugged terrain and sites with good concealment while kill sites were selected in mountainous habitats. Human infrastructure did not affect leopard resting and kill site selection. Thus, the capacity of leopards to perform essential life-supporting behaviours while coexisting with people appears to be primarily driven by their ability to remain concealed, rather than spatially avoiding humans.

BackgroundHuman-wildlife conflict, which motivates retaliatory killings, is a major driver of species decline globally. Addressing an open question in human-wildlife conflict, we test whether evolutionary-rooted human attitudes, independent of economic losses, better predict retaliatory responses. MethodsWe examined human attitudes toward spectacled bears (Tremarctos ornatus) and other wild carnivores in a wildlife conflict-zone in southern Ecuador by conducting interviews in rural communities. We measured both established variables - such as education levels, age, and gender - and novel psychometric variables to identify predictors of human-wildlife conflict responses. ResultsPerceptions of animals emerged as the strongest predictor of conflict responses. Communities exhibiting high levels of vengefulness, particularly within an animal-directed Culture of Honor, where individuals, especially men, are expected to respond strongly or violently to perceived threats, were more likely to support lethal interventions. Conversely, individuals with strong environmental education backgrounds demonstrated more positive perceptions of wildlife, highlighting educations potential role in conflict mitigation. ConclusionEvolutionary-derived attitudes, rather than economic factors, primarily drive human responses to wildlife conflict. Effective strategies to reduce violence against wildlife should incorporate human perceptions and culturally rooted values to address the underlying social and psychological drivers of conflict.

BackgroundHuman-Wildlife Conflict is emerging as one of the most critical conservation and socio-economic challenges in the Ecuadorian Andes, where both rural livelihoods and native fauna are under increasing pressure. Small-scale livestock producers in the region depend almost entirely on a limited number of cattle, meaning that the loss of even a single animal can lead to severe economic hardship. In response, antagonistic actions against wildlife are frequent, further threatening vulnerable species. At the same time, the recent proliferation of feral dogs adds a new dimension to conflict, posing risks to both livestock and native fauna. Despite the growing severity of this conflict, little is known of its drivers, spatial patterns, and socio-ecological consequences. This study seeks to fill that gap by generating insights to inform targeted conservation strategies for community-based mitigation of conflict with spectacled bears and feral dogs. MethodsTo assess the drivers and dynamics of HWC in southern Ecuador, we conducted structured interviews with livestock owners, quantifying the frequency and intensity of conflicts across multiple species and evaluating whether farm composition and management practices predict conflict patterns. ResultsOur results reveal that large carnivores cause significantly higher economic losses than smaller predators; furthermore, feral dogs have emerged as the primary source of financial damage over the past five years. Farms with a greater proportion of forest edge were associated with a higher probability of severe conflict, particularly with large carnivores. ConclusionsThese findings underscore the urgent need for proactive strategies to promote coexistence. Identifying predictive variables of conflict risk is crucial for vulnerability assessments and the design of effective mitigation policies. Controlling feral dog populations is likely to be a critical step in safeguarding both rural human livelihoods and native biodiversity in the Andean landscape.

The rising demand for outdoor recreation worldwide may be undermining the conservation objectives of protected areas (PAs). We leveraged a natural experiment, in which two adjacent PAs were closed to the public for different durations during the COVID-19 pandemic. Using detections from 39 camera traps in Joffre Lakes and Garibaldi Parks, Canada, from 2020-2022, we examined how recreation influenced mammal habitat use and diversity. Bayesian regression showed weak evidence that, when recreation was higher, detections declined for black bear, mule deer, and marten, while detections of bobcat and hoary marmot shifted closer to trails. Accumulation curves revealed that species richness and diversity were higher in the closed vs. open PA in 2020 (mean differences of -5.04 for richness and -0.33 for Shannon diversity). However, diversity did not decline consistently despite increases in recreation in 2021 and 2022. Notably, several rare species were only detected in the lower-recreation PA, suggesting they may be filtered out of the higher-recreation PA. This emphasizes the need for long-term monitoring to detect delayed and cumulative effects of recreation on mammal communities. Given growing global pressures on biodiversity, we urge PA managers to prioritize adaptive management to assess and balance outdoor recreation with conservation goals.

AimHuman land-use has dramatically altered the amount, quality, and connectivity of habitat for species worldwide. Understanding how these changes affect individual species is essential for predicting the overall consequences of land-use change for biodiversity. LocationThe Caribbean island of Puerto Rico. Forest cover on the island increased from about 18 to 45% from the late 1940s to the early 2000s. MethodsUsing data on geographic distributions and functional traits for 454 tree species, we evaluated how gain of potential habitat was related to species-specific climatic associations and life-history strategies. We estimated species-specific potential habitat (climatically suitable and forested) with species distribution models and data on forest cover. We characterized each species niche breadth (the range of environmental conditions it occupies) and niche position (the environmental conditions it prefers) to compare with the conditions in reforested areas. ResultsSpecies with relatively more potential habitat in 1951 (climatically suitable and forested) also had relatively larger gains in potential habitat from 1951 to 2000. Species that tend to occupy conditions different from those common in reforested areas (i.e., more marginal habitats) gained relatively less potential habitat and species with broad environmental niches gained more potential habitat. Additionally, species with relatively acquisitive functional traits gained more suitable habitat than those with relatively conservative traits. Main conclusionsOur results show that Puerto Ricos reforestation preferentially increased habitat for species that (1) already had suitable habitat in the landscape, (2) tolerate a wide range of climatic conditions, and (3) exhibit fast, acquisitive functional strategies. These findings illustrate how land-use change in heterogeneous tropical landscapes can generate non-uniform habitat gains across species, potentially favoring generalist over specialist species and reshaping community composition.

O_LITropical dry forests are among the most threatened ecosystems globally, yet the consequences of livestock overgrazing for ant communities remain poorly documented, particularly in the Tumbesian biodiversity hotspot of southwestern Ecuador, where uncontrolled goat grazing constitutes the dominant disturbance agent. C_LIO_LIWe sampled ant communities (Formicidae) across a goat-grazing disturbance gradient in Zapotillo (Loja Province, Ecuador), establishing three disturbance levels (Dense, Semi-dense, and Open Forest) with nine 60 x 60 m plots per level (n = 27) and 486 pitfall traps. Community responses were assessed using abundance-based and presence-absence analyses of morphospecies richness, Hill-number diversity, community composition, beta diversity decomposition, and functional guild structure; vegetation structure was characterized using satellite-derived NDVI. C_LIO_LIWe recorded 47,459 individuals belonging to 22 morphospecies in six subfamilies. Morphospecies richness declined with disturbance (Dense: 19, Semi-dense: 15, Open: 12), with four specialist genera exclusive to Dense Forest. Beta diversity decomposition revealed a shift from turnover-dominated dissimilarity at moderate disturbance to nestedness-dominated dissimilarity at high disturbance, indicating progressive habitat filtering as the dominant community-restructuring process. C_LIO_LICommunity composition differed among disturbance levels (PERMANOVA: F = 4.49, R{superscript 2} = 0.272, p = 0.001) and was correlated with NDVI (r{superscript 2} = 0.341, p = 0.013). Cryptic/soil and Leaf-cutter guilds were nearly eliminated from Open forest while the Opportunist guild expanded markedly, indicating that functional homogenization precedes detectable taxonomic impoverishment. C_LIO_LIOvergrazing drives directional ant diversity loss and biotic homogenization at both taxonomic and functional levels in the Tumbesian dry forest, underscoring the conservation value of intact Dense forest. C_LI

Humans are profoundly reshaping the natural world. These changes are giving rise to complex and mutually risky dynamics between people and large carnivores. In protected areas across North America, bears (Ursus sp.) face rapidly rising recreation pressures that can alter their use of the landscape, either displacing them from high-quality habitats or drawing them into human-wildlife conflicts through habituation or attraction to anthropogenic resources. However, disentangling responses to recreation from other drivers can be difficult because human activity covaries with environmental and seasonal processes that also shape bear activity. We leveraged the partial closure of the popular Berg Lake Trail in Mount Robson Park, British Columbia, Canada, to investigate whether black (Ursus americanus) and grizzly bears (Ursus arctos) showed fear, attraction or neutral behavioural responses to varying recreation levels across multiple spatiotemporal scales. To understand both anticipatory responses to predictable patterns of human activity, and reactive responses to hiker events, we used detections from 43 camera traps over two years (July 2023-June 2025). We compared weekly habitat use, daily activity patterns, and direct responses to hikers (using Avoidance-Attraction Ratios; AARs) among camera sites and between open and closed sections of the trail. Our results revealed that both bear species exhibited patterns consistent with fear responses, while some black bear behaviours were also consistent with attraction responses. Both kinds of responses reflect anticipatory strategies rather than reactionary behaviours (i.e., no AAR effect). Neither species avoided recreation spatially at the weekly scale: black bears were detected more at site-weeks with greater recreation intensity, while grizzly bears were consistently detected more at sites closer to hiking trails. However, both species used daily temporal partitioning to avoid direct encounters with humans. These findings demonstrate scope for human-bear coexistence when recreation levels are managed to be moderate and predictable, and bears have sufficient space to segregate from humans during peak times. Thus, successful coexistence will hinge on co-adaptation by both bears and people. Understanding how recreation influences bear behaviour, and the spatiotemporal scale at which that occurs, is critical for guiding effective adaptive management aimed at fostering human-bear coexistence in high-traffic protected areas.

Animal population control is widely used to mitigate conflicts between wildlife and agriculture worldwide. Structured, monitored removals are rare in South America, however, and their consequences for wildlife populations as well as their effectiveness in reducing crop damage are little understood. Using eight years of data from an experimental white-lipped peccary management program in an agricultural mosaic in the Brazilian Cerrado biome, we assess how structured, non-lethal removals affect both peccary demography and second-crop corn damage. Leslie removal models based on 6,619 captured individuals indicated that cumulative removals to approximately 85% of the initial population strongly reduced peccary abundance, with limited demographic compensation despite fluctuations in reproductive output. Corn crop damage, quantified with satellite imagery, declined over time and was correlated with peccary population size. Interannual variation in population growth and juvenile recruitment was poorly explained by climate, fire, or landscape composition. Source-sink dynamics likely play a role in maintaining healthy populations at the regional scale. Together, these results demonstrate that sustained and monitored ungulate removals can reliably reduce population size and agricultural damage, supporting coexistence between wildlife and food crop production in human-dominated tropical landscapes.

As global reptile populations continue to decline, improving reproductive success in managed populations of listed species, such as Phrynosoma cornutum (the Texas horned lizard) has become increasingly critical for species survival. One understudied area of reproductive research in reptile species is gamete collection and storage, a crucial component for maintaining genetic diversity. In Texas, semen was collected from wild P. cornutum (n = 20) in June 2025. Semen collection was performed via electroejaculation (EEJ) under alfaxalone anesthesia. Prior to semen collection, snout-vent-lengths (SVL) and weights were recorded and testes measurements were taken using a portable ultrasound. Average sperm motility and concentration across all lizards was 83.7% and 85.7 x 106 sperm/mL, respectively. While lizards with longer SVLs had higher sperm motility, weight and testis size did not affect sperm parameters. Samples were extended in INRA96 and divided for use in cold-storage longevity or cryopreservation trials. Samples under cold-storage conditions were assessed for motility daily for 10 days. Motility was not significantly reduced until 48 hours post-collection and maintained 19% motility at day 10. For cryopreservation, samples were diluted 1:1 in INRAFreeze cryopreservation media and frozen in liquid nitrogen, then immediately thawed. Average post-thaw sperm motility was 13.9%, with the highest post-thaw motility recorded at 38.2%. This is the first report of semen storage and cryopreservation in Phrynosoma and provides valuable insight into semen storage potential in reptile species.

The long-standing misconception that the Galapagos petrel (Pterodroma phaeopygia) and the Hawaiian petrel (Pterodroma sandwichensis) were conspecific masked the severe vulnerability of the Galapagos population. By the time its distinct status was recognized, the Galapagos petrel was already in marked decline, primarily due to invasive predators. Consequently, sustained rodent control programs have been implemented on Santa Cruz Island. An unintentional one-year failure in rodent control provided a rare quasi-experimental opportunity to quantify the demographic consequences of the invasive black rat predator. During this year, hatching success declined by [~]35% and breeding success by [~]40% relative to long-term means (66% and 62%, respectively), representing a substantial reproductive collapse. Fledging success exhibited a comparatively modest decline (from a long-term mean of 94% to 86% in 2017), suggesting stage-specific vulnerability. These results support the hypothesis that invasive black rats primarily affect early reproductive stages through egg predation and predation on small chicks, while older chicks surpass a critical size threshold that reduces susceptibility. Across the remaining managed years, reproductive metrics exhibited great stability, demonstrating the petrels resilience against other environmental or climatic stressors. Our findings provide robust empirical evidence that invasive rodent control is the dominant driver of reproductive success in this endangered seabird. The quasi-experimental failure underscored both the effectiveness and the necessity of continuous predator management, highlighting the severe and immediate consequences of even short-term lapses.

Predation is a driving force in the ecology and evolution of prey, and primates exhibit diverse anti-predator strategies for minimizing risk. Because these behaviors can be costly, individuals must balance costs and benefits when responding to perceived threats. The cognitive capacity and behavioral plasticity of baboons make them an ideal taxon for studying the context-dependent variation in anti-predator strategies. Here, we used an autonomous, motion-activated playback experiment to study the behavioral responses of chacma baboons (Papio ursinus griseipes) to simulated predator encounters in Gorongosa National Park, Mozambique. We compared responses in 2021, when predator densities were relatively low, to responses in 2024, after predation increased due to lion (Panthera leo) population recovery and African wild dog (Lycaon pictus) reintroduction. We compared flight and vigilance responses to vocalizations of these common predators with responses to leopard (Panthera pardus), historically a key predator; spotted hyena (Crocuta crocuta), a rare predator; and cheetah (Acinonyx jubatus), absent historically and currently. We also assessed how responses varied with habitat, age-sex class, presence of offspring, and group size. Across 916 predator playbacks, baboons fled in 19% and displayed vigilance in 71% of trials. When predator density was higher, baboons displayed weakened antipredator responses, consistent with the risk allocation hypothesis. Baboons were more likely to flee in response to lion and wild dog cues. Juveniles fled more frequently than other demographic classes, while adult females with offspring were more vigilant. Overall, responses were highly heterogeneous, reflecting the substantial intraspecific variation and behavioral flexibility characteristic of baboons.

IntroductionHuman land-use intensification and the resulting habitat loss are primary drivers of insect pollinator declines. Habitat restoration offers a promising approach to counteract these declines, yet landscape-level evaluations of bee responses to restoration and management remain limited. We conducted a two-year, landscape-scale study in Wisconsin, USA, to assess how different intensities of tallgrass prairie restoration and management affect bumble bees (Bombus spp.). ObjectivesThis study aimed to determine whether (1) bumble bee abundance and diversity increase with assisted restoration, and (2) outcomes differ between low-(seeded only) and moderate-intensity (seeded and managed with prescribed fire) interventions. MethodsUsing catch-and-release surveys, we measured bumble bee abundance and diversity at 32 sites representing a gradient in restoration intervention: no intervention (unassisted recovery), low intervention, and moderate intervention. ResultsBumble bee abundance and diversity were higher at assisted restoration sites (low and moderate intervention) than at unassisted sites. Although both tended to be greater at moderate than low intervention intensities, these differences were not statistically significant. Bumble bee community composition also differed across intervention intensity, driven by shifts in dominant species (e.g., B. impatiens and B. griseocollis). Rarer taxa, including endangered and vulnerable species, occurred only at assisted restoration sites, with the largest populations at moderate intervention sites. Across all sites, bumble bee responses were strongly and positively associated with floral abundance, but not with semi-natural habitat in the surrounding landscape. ConclusionOur findings demonstrate that assisted grassland restoration can effectively increase bumble bee abundance and diversity, supporting its value as a conservation practice for pollinators. Implications for Practice: (1) Grassland restorations targeting plant communities can successfully support nontarget pollinators across a range of management intensities and landscape contexts. Adding seeds of pollinator-preferred plants could improve restorations with low floral abundance and diversity. (2) Management of existing restorations is important to maintain abundant floral resources and diverse pollinator communities. Because sites varied widely in prescribed fire use, our findings likely represent a conservative estimate of its benefits, and higher intervention intensity (e.g., repeated seeding, regular fire, mechanical or chemical shrub and invasive plants control) may further enhance outcomes for bumble bees.

The Socotra Cormorant (Phalacrocorax nigrogularis) is a threatened seabird endemic to the coastal areas of the Arabian Gulf and the Arabian Sea, two regions separated by the Strait of Hormuz. Conserving threatened species requires clear delineation of population boundaries and the evaluation of genetic diversity. However, information on population structure and genetic variation, necessary for such an assessment, is lacking for the Socotra Cormorants. In this study, we assessed population structure and genetic diversity of Socotra Cormorants using two contrasting genetic markers: (1) maternally inherited mtDNA cytochrome oxidase 1 (COI) and (2) a nuclear non-coding region, {beta}-fibrinogen intron 7 (FIB7). A total of 279 individuals were sampled from four colonies in the Arabian Gulf and one colony on Hasikiyah Island in the Arabian Sea. Findings based on COI-variation suggest that the Arabian Gulf colonies represent one large population with extensive gene flow between Gulf colonies--except for the most distant pair of colonies--but isolated from Hasikiyah in the Arabian Sea. COI-variation indicated significant differentiation between the colonies inside the Gulf and the Hasikiyah colony. This is consistent with the reported distribution patterns, and may reflect phylogeographic processes of the region. The Gulf population showed substantially lower COI-diversity, with significantly lower nucleotide and haplotype diversity compared to Hasikiyah. In contrast, FIB7 results indicated extensive connectivity among colonies, with no detectable population structure or significant differences between the Gulf population and Hasikiyah. This study presents the first characterization of population structure and genetic diversity of Socotra Cormorants. The low genetic diversity coupled with relative isolation of the Gulf Socotra Cormorants raises conservation concerns regarding their long-term viability by potentially reducing fitness and eroding their evolutionary capacity to adapt to environmental change. LAY SUMMARYO_LIThe Socotra Cormorant is a threatened seabird found in the Arabian Gulf and Arabian Sea, but little was previously known about its population structure and genetic diversity. C_LIO_LIWe analyzed 279 birds from five nesting colonies (4 in the Gulf and 1 in the Arabian Sea), using two genetic markers to assess population connectivity and variation. C_LIO_LIWe found that the Socotra cormorants inside the Gulf appear to form a large, genetically isolated population with relatively low genetic diversity. C_LIO_LIThis is the first study that evaluates population structure and genetic diversity of this endangered seabird. C_LIO_LIThis is important information for the conservation of the Gulf Socotra cormorants because low genetic diversity, coupled with relative isolation, is associated with reduced fitness, and suggests that they may have a lower chance to adapt to environmental changes. C_LI

Enhanced AbstractO_ST_ABSBackgroundC_ST_ABSThere is overwhelming evidence that global change is having widespread, detrimental impacts on biodiversity. Population declines and local disappearances have been recorded with increasing frequency across all taxa, resulting in a steady rise in the number of threatened species. However, the number of documented extinctions remains counterintuitively low ([~] 1000 species across all kingdoms) compared to the sense of emergency pervading the scientific community. In isolation, that figure might fuel scepticism about the biodiversity crisis, but when put into context, it reveals that current extinction rates might be comparable to those that occurred during past mass extinction events estimated from the fossil record ([&ge;] 75% extinctions within < 2 million years). Although this is an important clue supporting the claim that we might now be witnessing a new ( sixth) mass extinction, it falls short of definitive proof. The claim bears such high importance that it requires exceptionally solid foundations. However, our main aim was not to ascertain whether current extinction rates qualify as a new mass extinction event in progress. Instead, we examined the intersection of potential future loss scenarios and species discovery rates to address the fundamental question of whether and when we will be able to confirm a mass extinction is under way. AdvancesOur extrapolations suggest that the timing for a mass extinction to materialise (2,604-34,808 years from now at 75% diversity loss) is consistent with past mass extinctions (e.g., 12,000-108,000 years estimated for the Permian-Triassic extinction to unfold) under modern extinction rates (loss of 0.004%-0.053% of global species richness per year). We identify the minimum necessary conditions in which we could confirm a mass extinction under the full range of assumptions related to total species diversity (ranging from < 1.8 million to 163.2 million animal species) and discovery rates (e.g., [~] 13,110 new animal species described per year as of 2026, with the number growing by [~]77 species per year), and the associated timeframe required. We show that there are many realistic future scenarios where we would fail to detect a mass extinction in progress. OutlookBased on available evidence, the rate of global biodiversity loss might already be consistent with the standard definition of a mass extinction. But even if true, current extinction rate estimates (20-8343 times background rates) would not necessarily imply a mass extinction is currently unfolding, because this claim can only be verified a posteriori. Our projections instead indicate that there is a high risk of not recognising a mass extinction as it unfolds -- 49% across all parametrisations we explored. Furthermore, the temporal scale required for a mass extinction to materialise is orders of magnitude longer than relevant policy and legislative horizons, a mismatch that might appear to absolve todays society of responsibility. In reality, the opposite is true -- underestimating the likelihood of already being on a trajectory toward a mass extinction could have catastrophic consequences for future generations and historical accountability. Future generations will be forced to confront a world they perceive as normal, unaware of how much better off humanity could have been.

In an era of severe global biodiversity threats, understanding the link between species traits and their endangerment helps uncover causes of risk and infer threats to understudied species. Most animals have complex life cycles with distinct stages that may face stage-specific threats. Current conservation frameworks rely heavily on adult traits, potentially misjudging extinction risk. Using Chinese anurans as a model, we integrated functional traits from both adult and tadpole stages to examine their association with extinction risk. We found that body size positively correlates with risk in both stages. Microhabitat use related with extinction risk in tadpoles but shows no significant link in adults. Adult relative tympanum diameter and head length also correlate with extinction risk. These results indicate that species vulnerability is shaped by multi-stage traits, with both shared and stage-specific threats. Conservation based solely on adult traits may fail to accurately assess species threats. We call for integrating a whole-life-history perspective into biodiversity assessment and conservation to more effectively address the global biodiversity crisis.

In wildlife forensic practice, species identification and estimation of the Minimum Number of Individuals (MNI) for highly processed specimens have long relied on weight-based conversion methods, which may result in underestimation of the number of individuals involved in a case. Focusing on confiscated casque products of the helmeted hornbill (Rhinoplax vigil), this study combines macroscopic morphological examination with mitochondrial DNA barcoding (16S rRNA, COI, and Cytb) to explore a more robust approach for individual quantification. The results demonstrate that the conventional "weight-based" approach overlooks critical biological information contained in anatomical structures and cannot accurately reflect the actual number of individuals involved. Based on this, we propose an anatomy-based criterion centered on the principle of structural uniqueness: specimens retaining biologically unique beak or casque structures should be directly assigned to a single individual, whereas weight-based estimation should only be applied when original anatomical features are entirely absent. In addition, considering material loss during processing, we propose approximately 85 g as a reference threshold for estimating the number of individuals in heavily processed solid casque products. This approach improves the scientific rigor and accuracy of forensic identification and provides reliable technical support for the conviction, sentencing, and law enforcement of wildlife trafficking cases involving helmeted hornbill and other endangered species.

O_LIChanges in habitat structure across species distributions may contribute to the generation and maintenance of range limits, but few studies have evaluated this by directly measuring habitat availability across relevant spatial scales. C_LIO_LIHere, we test the predictions that coarse-scale and patch-level habitat availability decline towards and beyond the northern range limit of Pacific coastal dune endemic Camissoniopsis cheiranthifolia. We used aerial imagery and geographic information system (GIS) tools to measure the coarse-scale availability of coastal dune habitat in California and Oregon. The availability of finer-scale habitat patches specifically suitable for C. cheiranthifolia was measured in a 2-generation field survey of > 4,200 5m x 5m plots randomly distributed across 1100 km of coastal dune habitat transcending the species northern range limit. At each plot, we estimated the proportion of area that contained suitable habitat as well as recorded occupancy by C. cheiranthifolia. As an alternative approach to visually estimating habitat suitability, we recorded plant community composition at each plot to predict beyond-range habitat suitability using a random forest model. C_LIO_LIContrary to our predictions, we found that coastal dune habitat, measured coarsely from aerial imagery, was more abundant and continuous towards and beyond the northern range limit. At the fine scale, however, the proportion of plots with suitable habitat (patch suitability) and the proportion of habitat within plots that was suitable (patch size) declined across the range limit. Moreover, patches were more isolated from one another and, in one survey year, less temporally stable towards and beyond the range limit. Finally, occupancy by C. cheiranthifolia was less likely in smaller, more isolated, and temporally unstable patches, providing mechanistic insight to the previously observed decline in occupancy towards the range limit. C_LIO_LISynthesis: Taken together, our results suggest that fine-scale habitat patch configuration changes in ways that likely impede patch colonization, thereby reducing occupancy and limiting the species northern distribution. Thus, consideration of geographic variation in patch and landscape structure, rather than only coarse-scale habitat availability, may be essential for understanding the processes that limit species ranges. C_LI

Migration is a well-described behavioural strategy that allows species to track variation in resources and climatic conditions by moving in response to seasonality. A common form is elevational migration, an annual short-distance movement undertaken by many mountain bird species globally. While studies show that the timing of migration may relate to food availability, the mechanisms determining which species migrate remain unclear. Our study investigated if the degree of dietary specialization explains why some high-elevation bird species in seasonal environments migrate downslope for the winter while others remain resident at high altitudes despite the apparent scarcity of their preferred food resources. We mist-netted birds along a 2300-m elevational gradient in the Eastern Himalaya and collected blood and faecal samples from 261 individual birds belonging to 18 species of high-elevation residents (ten) and elevational migrants (eight) in their breeding and wintering ranges. Using stable isotope ratios of carbon and nitrogen in whole blood and faecal DNA metabarcoding, we compared their seasonal trophic levels and dietary niches. Nitrogen isotope ratios showed that residents had a substantially lower trophic position in the winter compared to summer (-0.35 [-0.52, -0.17]), whereas migrants had a slightly higher trophic position in the winter (0.15 [-0.02, 0.32]). This trophic shift in residents was likely due to a decrease in insectivory and an increase in frugivory in the winter. The frequency of key insect orders (Lepidoptera, Hemiptera, and Coleoptera) declined by 20-35% in their winter diets alongside an increase in fruit, particularly from the family Polygonaceae (0.33 [0.18, 0.46]). Additionally, compared with residents, migrants showed greater overlap in their dietary niches between summer and winter (98% vs 80%). Because arthropod abundances in the Himalayas peak at high elevations in the summer and decline in the winter, we suggest that elevational migrants are likely dietary specialists that track resources, while high-elevation residents are dietary generalists that supplement their winter diet with fruit and nectar because of the scarcity of arthropods. These findings indicate that a species dietary specialization is linked to its migratory behaviour, providing a potential mechanistic explanation for how different species solve the challenge of seasonal resource limitation.