Biodiversity loss and zoonotic risk are critical global challenges. While protected areas (PAs) are essential for conservation, their potential to reduce zoonotic risk remains overlooked by researchers and policymakers. Specifically, the spatial overlap of conservation priorities and disease risk is poorly quantified. We analyzed 33,831 terrestrial vertebrate species to identify high-conservation-need (HCN) and high-zoonotic-risk (HZR) areas, finding that 46% of HZR areas overlapped with HCN areas. We identified key HCN-HZR areas globally and prioritized 30 countries; key areas covered only similar to 1% of global land, and average PA coverage in these countries was just 23%. Expanding PA coverage and enhancing surveillance tgcqin these key areas could address both biodiversity loss and public health risks, particularly in low-income countries. Managing these key areas required 6,500-45,000 additional rangers and $390-$1,822 million annually. Encouragingly, allocating just 0.01% of the national gross domestic product (GDP) would close most funding gaps.

Various human disturbances are displacing animals from suitable lowlands to high-altitude refuges worldwide. However, the mechanisms underlying this upward shift remain poorly understood, limiting the development of effective conservation strategies. Studying how animals adjust their habitat selection and utilization patterns in response to human disturbances offer critical insights into the ecological processes shaping their distribution in human-dominated environments. We investigated altitudinal ranging patterns of endangered Indochinese gray langurs (Trachypithecus crepusculus) in Wuliangshan National Nature Reserve (WNNR), China, from 2010 to 2019, across early, middle, and late habituation stages. Although vegetation surveys showed substantially higher food availability at 1750 m than at 2150 m and 2550 m, langurs preferred higher altitudes (2000-2600 m) farther from human settlements during early and middle stages. This vertical refuge selection reversed dramatically in the late habituation stage, with langurs shifted to lower altitudes, increased feeding activities there, and exhibited preference for areas below 2000 m outside the WNNR. This downward shift was associated with an increased intake of high-quality food resources (fruits and seeds). Our findings indicate that human activity initially displaced langurs to high-altitude refuges, and that continued habituation by researchers may have facilitated the reoccupation of resource-rich low-altitude habitats. These results underscore that species distribution models and resource selection functions relying solely on species occurrence data risks prioritizing refuges over ecologically superior habitats. We call for more field studies to document the behavioral shifts of study subjects in human-dominated habitats and their cascading impacts on local ecological communities and human societies.

Biodiversity in Southeast Asia is currently facing a significant decline, with primate species particularly impacted due to deforestation, poaching, global warming, and various other challenges. All 20 recognized gibbon species are considered at risk of extinction due to rapidly decreasing population sizes. The northern white-cheeked gibbon (Nomascus leucogenys) is among six gibbon species belonging to the genus Nomascus documented in Vietnam. This gibbon has been recorded in several protected areas, but significant populations persist only in a few locations, potentially including Vu Quang National Park (52.733 km2). In our study, we utilized the auditory point count method to collect data in the field and applied a distance sampling method to estimate the abundance of northern white-cheeked gibbons in Vu Quang National Park. A total of 27 gibbon groups were documented during our field survey. The estimated gibbon group density was approximately 0.48 groups/km², leading us to estimate the gibbon population size in Vu Quang National Park at about 155 groups. Vu Quang National Park therefore has the largest documented population of northern white-cheeked gibbons in Vietnam, highlighting the urgent need for prioritizing the conservation of this species.

Conservation effectiveness of protected areas (PAs) is determined by conservation interventions within PAs, as well as anthropogenic impacts from local communities surrounding PAs. Accounting for spatial heterogeneity of anthropogenic impacts at the sub-PA scale, populations of threatened species in different sectors of a PA may respond differently, even though conservation interventions are usually implemented congruously throughout the PA. As a case study, we assessed the population change of the Critically Endangered western black crested gibbon (Nomascus concolor) over the past decade in Wuliangshan National Nature Reserve in China. We also conducted interviews with 605 residents in 99 villages surrounding the reserve to obtain their gibbon knowledge and attitude toward wildlife, as well as their production activities in and outside the reserve. We then assessed the impact of environmental variables and anthropogenic factors on the gibbon population change. We found an overall increase in gibbon population through the reserve, although it varied across different sectors. Gibbon population change was positively affected by elevation and local residents' gibbon knowledge and attitude toward wildlife. Furthermore, demographic factors such as age, gender, and education level, as well as conservation outreach, contribute to gibbon conservation indirectly through enhancing residents' gibbon knowledge and attitude toward wildlife. Our study underlines the importance of incorporating local communities in threatened species conservation, suggesting that conservation outreach and community-based conservation are essential to the improvement of PA conservation effectiveness.

Animal coloration exhibits substantial biogeographic variation, reflecting complex adaptations to both abiotic and biotic environments. Although the evolutionary mechanisms underlying avian plumage coloration have been widely studied, geographic variation in plumage patterning has received far less attention. To extend our understanding of avian plumage evolution, we quantified global plumage coloration and patterning across 10 290 bird species using an extensive red‐green‐blue (RGB) dataset derived from illustrations in the Handbook of the Birds of the World. To test ecogeographical predictions, we modeled variation in plumage lightness, blue–yellow chromaticity, and pattern granularity using phylogenetic mixed models and path analyses. Our analyses revealed pronounced geographic heterogeneity in both plumage coloration and patterning. Variation in plumage lightness followed broad climatic gradients, and darker coloration was associated with humid and colder environments, consistent with the combined predictions of Gloger's rule (darker in warm, humid areas) and Bogert's rule (darker in cold areas). These rules are not contradictory but coexist; their relative influence is determined by whether humidity or temperature is the dominant selective force in a given region. While resident species in cold environments largely supported Bogert's rule for thermoregulation, migratory species and proficient fliers (e.g. gulls) deviated from this pattern by maintaining lighter plumage to avoid overheating during flight. Furthermore, we identified a strong latitudinal gradient along the blue–yellow axis: tropical humidity promotes carotenoid‐rich yellow plumage through dietary shifts, whereas higher latitudes favor structural blue hues. Patterning also showed large‐scale structure, with larger pattern elements linked to humid environments and larger body sizes rather than to specific foraging habitats. By integrating classical ecological rules with the thermoregulation hypothesis, our study provides a unified framework explaining how climatic constraints and ecological processes interact to shape the global distribution of avian coloration patterns.

Plant viruses cause symptoms with devastating consequences for agriculture. However, the molecular mechanisms underlying symptom development in viral infections remain largely unexplored. Here, we show that tomato yellow leaf curl virus (TYLCV) interferes with host developmental programs through a host-mimicking domain present in the viral C4 protein. This domain mediates the interaction between C4 and a family of RCC1-like domain-containing (RLD) proteins, previously shown to be required for proper plant development and environmental responses. C4 outcompetes an endogenous interactor of RLDs, hijacking RLD proteins to the plasma membrane and disrupting their function in orchestrating endomembrane trafficking and polar auxin transport. Strikingly, macroscopic symptoms do not affect viral accumulation in the plant but serve as attractants for the insect vector, presumably promoting pathogen spread in an ecological context. Our work sheds light on the molecular underpinnings and biological relevance of symptom development triggered by TYLCV in tomato. Since most plant viruses are insect-transmitted, the principles described here might have broad applicability to crop-virus interactions.

Protected areas (PAs) are essential to the success of global biodiversity conservation, and effectiveness evaluations with quantitative indexes are critically needed to enhance PA performance. Although species richness has been widely used as an index, it is naturally different among ecoregions, making large scale comparison across ecoregions inappropriate. Here, we suggest using the completeness index (CI) and defaunation index (DI) of animal communities as alternative indexes. We compiled a camera-trapping dataset consisting of over 2,023,000 camera days and 619,000 independent detections of 98 medium- and large-bodied mammals (MLMs) in 115 Chinese nature reserves. We then assessed CI and DI of MLMs for each reserve, and identified the environmental and social economic variables that may affect these indexes. We found that CIs and DIs varied greatly among these reserves, and we provided a list of reserves with high conservation priority (with high CIs) and those require restoration efforts (with high DIs). Furthermore, we found that medium-bodied mammals had a higher DI than large-bodied, herbivores had a higher DI than omnivores, and protected species had a higher DI than unprotected species. We also found that MLM communities were better retained in PAs with higher elevation and lower temperature. PA size, the reduction of human disturbances by PA, and scientific research also contributed to MLM community conservation. Our study provides suggestions to improve PA management in China, and demonstrates a new framework to evaluate conservation effectiveness of PAs across ecoregions.

Cao vit gibbon (Nomascus nasutus) is one of the world's 25 most endangered primate species, with only one population of 11 groups living in a small karst forest patch along the China-Vietnam international border. Assisted habitat regeneration is underway in both China and Vietnam to conserve the species. However, the lack of crucial information on habitat use and habitat preferences of these gibbons could severely compromise the conservation outcomes. To understand gibbon habitat use patterns and guide ongoing habitat restoration, we studied the ranging behavior of two cao vit gibbon groups in Bangliang Gibbon Nature Reserve, Guangxi, China. We established vegetation plots within gibbon's habitat along the altitudinal gradient. Then quantified food distribution in different altitudinal ranges. Both groups avoided using areas above 800 m, but preferred lower areas, and they spent more time feeding in low-altitude areas compared to high-altitude areas. Our analysis revealed that the altitudinal ranging pattern was affected by both food distribution and temperature. The gibbons preferred altitudes that provided more food for their diet, and their selectivity for lower altitudes increased as temperatures dropped while they adopted an energy-conserving strategy during cold seasons. Our results suggested that gibbons prefer habitats at lower altitudes, which serve as important feeding sites and provide refuges during cold exposure. Therefore, we strongly propose prioritizing reforestation in areas below 750 m by planting important food species.

Gut microbiota often undergo metabolic cross-feeding and resource competition. However, our understanding of global variations in these interactions and their implications for host health remain elusive. By analyzing a microbial genome catalog from 841 fecal metagenomes across 53 primate species worldwide, we identified key microbiota assigned to two taxa, i.e., Bacillota_A and Pseudomonadota, which well predicted the trade-off of community-level interaction types between metabolic competition and cooperation. Specifically, Bacillota_A species were inherently competitive and amino acid auxotrophic and typically found in anaerobic habitats. In contrast, members of Pseudomonadota were inherently cooperative, siderophore producers, and more abundant in aerobic conditions. Random forest models successfully distinguished unhealthy gut samples from healthy samples through the key competitive and cooperative microbiota, suggesting potential links between community metabolic interactions and host health. Together, this study enhances our mechanistic understanding of microbial interaction dynamism within complex gut ecosystems, offering new targets for understanding host health.

The lack of knowledge regarding the basic ecological traits of an endangered species may lead to traps in habitat restoration efforts. Understanding the ranging ecology of endangered species is essential in avoiding these traps. The Hainan gibbon (Nomascus hainanus), the world's rarest primate, reportedly takes refuge in suboptimal montane habitats and occupies an abnormally large home range, resulting in suggestions for enhancing montane habitat quality with high priority. However, these conservation suggestions and actions are not based on solid science. For the first time, we habituated two groups of Hainan gibbon, and studied their ranging ecology over a year from January to December 2022. We found that the average home range size of these groups was 164.5 ± 70.6 ha (95% KDE-href) and 155.2 ± 71.1 ha (95% MCP), which is comparable to other Nomascus gibbons and represents an adaptive trait in response to their heterogeneous habitat. Furthermore, gibbons have shown a preference for higher-altitude habitats between 800 and 1100 m, where food is more abundant than in low-altitude habitats. Our findings, combined with the evidence of favorable food conditions and short interbirth intervals of the Hainan gibbon, indicate that montane habitats meet gibbons' life-history requirements and are suitable for them. The idea that "montane habitat is suboptimal" is a cognitive trap. Given the Hainan gibbons' isolated habitat is approaching saturation, we suggest prioritizing ecological corridor construction to enable gibbons to rapidly gain access to other suitable montane forests.

It is widely suspected that a small percentage of males have exceptional reproductive output (ERO) but progeny numbers of males are rarely measurable, even in humans. If we define the variance ratio of reproductive-output in males and females as α' = VM /VF , the ERO hypothesis would predict α' ≫ 1. Since autosomal, X, and, Y chromosomes are found in males 1/2, 1/3, and 100% of the time, their DNA diversities can inform about α'. For example, autosomal and Y-linked diversities are governed, respectively, by (VM + VF )/2 and VM . When comparing the chromosomal diversities, α' appears to be near 20 for chimpanzees and orangutans, and 1-10 for gorillas. The exception is bonobos with α' < 1. In humans, extensive genomic data are coupled to a theory, developed herein, that can filter out selection influences on Y-linked diversities. Hence, the estimation of α' is rigorous, yielding values near or above 20, depending on the population. When α' > 10, the presence of ERO males is very likely. These analyses can be applied more generally to species with XY sex determination.

Conservation practices for extremely small populations must be grounded in solid science to prevent extinction. Hainan gibbon (Nomascus hainanus) is the world's rarest primate species; however, insufficient data on its habitat suitability and genetic status impede evidence-based decisions for habitat restoration. Here, we conducted a comprehensive analysis of Hainan gibbons' energy intake and expenditure, reproductive parameters, and genetic diversity based on field research (March 2021 to December 2022) and long-term historical data (2003 to 2024). By comparing our results with those of captive gibbons and other free-feeding captive primates, we found that Hainan gibbons can obtain sufficient energy for growth and reproduction in their existing habitats. Furthermore, we identified an additional D-loop haplotype indicating that the current population is more genetically diverse than previously thought. However, recently formed adult male-female pairs are increasingly related, signaling a high risk for inbreeding within this small population. Based on these findings, we highlight an urgent need to expand available habitat by building corridors.

In forested environments it is challenging for fruit-eating animals to select fruits that meet their nutritional needs. Primates base their food choices on fruit phenotypic traits such as color and tactile cues to determine nutrient content to improve foraging efficiency. However, are fruit phenotypic traits reliable indicators of nutrient content? To answer this question, we integrated observations of feeding behavior with the nutritional and physical characteristics of the fruits in the diet of two sympatric primates (Nomascus concolor and Trachypithecus crepusculus) in a subtropical forest in Southwestern China. Gibbons chose fruits with high total non-structural carbohydrate content that have high chromatic contrast against a predominantly green background, while langurs chose fruits with high crude protein content and high hardness. The chromatic contrast exhibited a significant positive correlation with the carbohydrate content, and the fruit hardness demonstrated a significant positive correlation with the protein content. Chromatic conspicuousness and hardness may serve as important fruit foraging cues for gibbons and langurs. This study adds to our growing understanding of how Old World primates use color vision and tactile cues while foraging and provides new insights to the evolution of diverse animal sensory systems.

Disaster risk reduction, an essential function of protected areas (PAs), has been generally overlooked in PA design. Using primates as a model, we designed a disaster risk index (DRI) to measure the disaster sensitivity of primate species. High-conservation-need (HCN) areas were identified by both their richness and number of threatened primate species. We also constructed high-disaster-risk (HDR) areas and climate-sensitive (CS) areas based on a disaster risk assessment and temperature change under climate change. We overlaid HCN and HDR areas to obtain HDR-HCN areas. We defined species conservation targets as the percent of each species’ range that should be effectively conserved using “Zonation”. Landslides had the highest DRI (1.43 ± 0.88), but have been overlooked in previous studies. PA coverage in HDR-HCN (30 %) areas was similar to that in HCN areas (28 %), indicating that current PA design fails to account for disaster risk reduction. About 50 % of the HDR-HCN areas overlapped with CS areas. Presently, 43 % of primate species meet their conservation targets. Fifty-seven of primate species would meet their conservation targets and 67 % of primates could benefit from PA expansion if HDR-HCN areas are fully incorporated into PAs. Increasing PA coverage in HDR-HCN areas is essential to achieving both primate conservation and disaster risk reduction. The study calls for integrating disaster risk reduction into PA design guidelines, particularly in regions like the western Amazon, and recommends flexible conservation approaches in other areas.

Wild animals face numerous challenges in less ideal habitats, including the lack of food as well as changes in diet. Understanding how the gut microbiomes of wild animals adapt to changes in food resources within suboptimal habitats is critical for their survival. Therefore, we conducted a longitudinal sampling of three gibbon species living in high-quality (Nomascus hainanus) and suboptimal (Nomascus concolor and Hoolock tianxing) habitats to address the dynamics of gut microbiome assembly over one year. The three gibbon species exhibited significantly different gut microbial diversity and composition. N. hainanus showed the lowest alpha diversity and highest nestedness, suggesting a more specialized and potentially stable microbial community in terms of composition, while H. tianxing displayed high species turnover and low nestedness, reflecting a more dynamic microbial ecosystem, which may indicate greater sensitivity to environmental changes or a flexible response to habitat variability. The gut microbial community of N. concolor was influenced by homogeneous selection in the deterministic process, primarily driven by Prevotellaceae. In contrast, the gut microbial communities of H. tianxing and N. hainanus were influenced by dispersal limitation in the stochastic process, driven by Acholeplasmataceae and Fibrobacterota, respectively. Further, the microbial response patterns to leaf feeding in N. hainanus differed from those of the other two gibbon species. In conclusion, this first cross-species comparative study provides initial insights into the different ecological adaptive strategies of gut microbiomes from a point of community assembly, which could contribute to the long-term conservation of wild primates.In this study, we conducted longitudinal sampling of three gibbon species living in high-quality (Nomascus hainanus) and suboptimal (Nomascus concolor and Hoolock tianxing) habitats to address the dynamics of gut microbiome (composition, alpha diversity, beta diversity and assembly process) over one year.

Human activities have driven biodiversity loss for millennia, and conservation of 'refugee species' that survive as remnant populations requires insights from historical baselines. However, reconstructing the past distribution and ecology of such species is challenging due to data limitations with specimen-based archives. Here, we assess the taxonomic identity of two gibbon mandibles from the Wumingshan Neolithic site in Guangxi, China. Although ancient DNA extraction was unsuccessful, a suite of linear and geometric morphometric analyses using dental and mandibular characters reveals that these mandibles fall within or close to variation shown by extant Chinese Nomascus gibbons and can be assigned to the cao vit gibbon N. nasutus. This is now one of the world's rarest mammals, with a surviving population of 74 individuals in one site. Comparative assessment of bioclimatic, abiotic and anthropogenic parameters for Wumingshan and other sites where N. nasutus historically occurred reveals the species was formerly a landscape generalist but is now restricted to a high-elevation refugium with reduced human pressures. Our multidisciplinary analyses provide a new baseline on niche requirements and vulnerability for N. nasutus with implications for population management, demonstrating the importance of integrating environmental archives into conservation planning.

Strengthening research capacity is essential to address the global biodiversity crisis. Yet, parachute science often undermines this goal, and its prevalence, costs, and benefits are unclear. We analyzed 13,502 publications on primate research that we extracted from Scopus (1960-2022) to evaluate the effects of parachute science on local research capacity across primate-range countries. We categorized these publications as local (LRP), collaborative (CRP), or parachute science (PSRP) research publications and categorized countries where the research took place as low- to middle-income countries or high- to upper-middle-income countries. We used generalized linear mixed-effects models to assess how parachute science influenced local research capacity. For 69% of PSRPs, the research was conducted in 59 low- to middle-income countries. For 20% of LRPs, research was led by people from these 59 countries. The disparity in LRPs among country groups was large. Local research publications in high- to upper-middle-income countries were at least 3.6 times higher than those in low- to middle-income countries. Before 2013, parachute science contributed to an increase in LRPs; this trend reversed after 2013, mainly resulting in a decline in LRPs across all countries and both income categories. Strengthening the capacity to share research in low- to middle-income countries is urgent if international conservation commitments are to be met. We recommend establishing true collaborative and interdisciplinary research teams, expanding local research opportunities, and supporting long-term research projects as key strategies for sustainable research capacity strengthening in low-income countries.