International Journal of Primatology最新文献

{"title":"Genetic Diversity, Geographical Structure, and Demographic History of the Kashmir Gray Langur (Semnopithecus ajax)","authors":"Shahid Hameed, Md Niamat Ali, Shivakumara Manu, Kunal Arekar, Mehreen Khaleel, Tawqir Bashir, Govindhaswamy Umapathy","doi":"10.1007/s10764-024-00455-1","DOIUrl":"https://doi.org/10.1007/s10764-024-00455-1","url":null,"abstract":"<p>Genetic diversity allows species to survive in a dynamic environment where selective criteria are ever-changing. As a result, the long-term survival of a species can be affected by its levels of genetic diversity. The Kashmir gray langur, <i>Semnopithecus ajax</i>, is an Endangered primate species endemic to the northwestern Himalaya. It has a fragmented distribution, is exposed to severe anthropogenic and climatic pressures, and has received little scientific attention. We investigated patterns of genetic diversity, population structure, and demographic history in wild populations of the Kashmir gray langur in the Kashmir Himalaya. We sampled 15 langur groups by using noninvasive sampling for scat collection and also obtained a tissue sample from a dead langur for whole-genome sequencing. We sequenced a mt-DNA fragment encompassing part of the noncoding D-loop region (728 bp) for 63 samples and protein-coding Cytochrome b (775 bp) for 37 samples. We generated whole-genome data by using PCR-free shotgun sequencing. We also reconstructed the demographic history of the Kashmir gray langur through coalescent analysis using MSMC2. We observed (± SD) lower haplotype (Hd = 0.207 ± 0.088) and nucleotide (π = 0.00126 ± 0.00077) diversity in Cytochrome b (693 bp) gene sequences than in noncoding partial D-loop (625 bp) gene sequences (Hd = 0.878 ± 0.026 and π = 0.00735 ± 0.002). Concatenated alignment (Cytochrome b and D-loop, 1318 bp) defined 21 unique haplotypes with haplotype diversity of 0.935 ± 0.024 and nucleotide diversity of 0.00532 ± 0.00193. The haplotype network and maximum likelihood phylogenetic tree revealed strong signatures of genetic differentiation among geographic populations, with the Jhelum River appearing to be a prominent barrier to gene flow between these populations. We found no evidence of isolation-by-distance. Mean genome-wide heterozygosity was very low (0.00034). We estimated the long-term effective population size to be 8,702 individuals; however, the most recent estimate indicated a lower value of 1,844 individuals. Our study emphasizes the need for habitat connectivity to mitigate the negative impacts of habitat loss and fragmentation on the genetic diversity of terrestrial and arboreal animals inhabiting the Himalayan ecosystems, particularly habitat specialist species.</p>","PeriodicalId":14264,"journal":{"name":"International Journal of Primatology","volume":"9 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142191098","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Range-wide Distribution Survey, Habitat Modeling, and Characterization of Conservation Threats to the Colombian Black Spider Monkey (Ateles fusciceps rufiventris) in Colombia","authors":"Alma Hernández-Jaramillo, Sam Shanee, Juan Carlos Serio-Silva","doi":"10.1007/s10764-024-00457-z","DOIUrl":"https://doi.org/10.1007/s10764-024-00457-z","url":null,"abstract":"<p>Knowledge of the geographic distributions of species is fundamental for conservation management. <i>Ateles fusciceps rufiventris</i> is currently listed as Vulnerable. It is found in Colombia and Panamá and may be present in Ecuador. It has been subject to very few studies and its true current conservation status is unknown. We used 3 years of interviews and field observations to determine its current distribution in Colombia, complemented with searches of the literature and databases for the entire range. We evaluated the quality of available habitat using a publicly available data layer of forest integrity information and niche modeling. We estimated the original and current extent of occurrence (EOO) of the taxon based on an ecological niche model (ENM) using MaxEnt and calculated the area of occupancy (AOO) for Colombia, where we conducted field sampling. We also identified the main threats to the subspecies during our interviews and field observations. Of the 39 sites we visited, we confirmed the presence of <i>A. f. rufiventris</i> by direct observation or secondary information at 15 (38%), although all sites had potential habitat for the subspecies. We estimated that the EOO of <i>A. f. rufiventris</i> in Colombia covers 118,730 km² and that forests in the potential habitat have reduced by ~ 60% in the last 30 years, leaving an estimated current AOO in Colombia of ~ 17,800 km² to ~ 47,000 km², with just 11% in state-protected areas. Interviews and field observations showed that clearcutting for agriculture and cattle ranching were the most frequent threats at sites where we found no evidence of the subspecies. Illegal crops, hunting for subsistence and trade, including as pets, were the most frequent threats at sites where we found the subspecies. We found a dramatic reduction in suitable habitat and a high incidence of forest degradation, deforestation, and hunting affecting the subspecies. Conservation efforts should focus on restoration in strategic areas, and on reducing deforestation and hunting pressure. Community-based conservation could be employed to increase areas of protected habitat on communal lands and decrease hunting pressure, to ensure the long-term survival of this highly threatened primate.</p>","PeriodicalId":14264,"journal":{"name":"International Journal of Primatology","volume":"312 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142224852","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of Seasonality on Food Selection and Home Range Size of the Western Hoolock Gibbon (Hoolock hoolock)","authors":"Sabit Hasan, Habibon Naher, Tania Akhter, Tanvir Ahmed, Hassan Al-Razi, Hasan A. Rahman, Sabir Bin Muzaffar","doi":"10.1007/s10764-024-00452-4","DOIUrl":"https://doi.org/10.1007/s10764-024-00452-4","url":null,"abstract":"<p>Diet and home range use patterns provide information on the needs of species faced with changing forest quality. Many primates have diets and foraging strategies that maximize nutrient uptake and minimize energy expenditure, resulting in well-defined home ranges. Primates use their home range in varying ways depending on the spatial distribution of resources. The western hoolock gibbon (<i>Hoolock hoolock</i>) is a small, frugivorous ape that maintains a home range in closed-canopy forests. The species is globally Endangered and lives Bangladesh, India and Myanmar in shrinking forest patches. We studied a group of gibbons, consisting of two adult males, an adult female, an immature male, and an infant in Lawachara National Park in northeastern Bangladesh. We used scan sampling to determine their diet, home range size and daily path lengths from April 2019 to March 2020. We also mapped fruiting trees and sleeping sites within their home range from April 2019 to March 2020. The gibbons’ diet varied seasonally, but fruits (mostly figs) dominated throughout the year (fruits: 51%; leaves: 35%; flowers: 5%; buds: 6%), peaking in the monsoons. Home range size was 50.79 ha (90% Kernel Density Estimate) or 47.72 ha (Grid Cell Method). The mean daily path length was 1057.2 m (range 451–1938; <i>n</i> = 33). The home range was smaller during the monsoons and larger in winter. Daily path lengths decreased in the monsoon likely because of abundance of fruits, and also decreased in winter, possibly owing to low temperatures. Gibbons used multiple sites for foraging and slept in large trees with a dense canopy. They slept at a mean of 22.82 m (range 16–30 m) above ground in trees with lianas, possibly as an antipredator strategy. Continued monitoring of ecological factors that influence gibbon foraging and habitat use can help to formulate targeted conservation plans for this Endangered small ape.</p>","PeriodicalId":14264,"journal":{"name":"International Journal of Primatology","volume":"2 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142191099","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Vocal differences in note, sequence and great call sequence among three closely related Nomascus gibbon species","authors":"Pu Han, Hai-gang Ma, Zi-di Wang, Peng-lai Fan, Peng-fei Fan","doi":"10.1007/s10764-024-00449-z","DOIUrl":"https://doi.org/10.1007/s10764-024-00449-z","url":null,"abstract":"<p>The vocal structure of gibbons has long been believed to be under strong genetic control and consistent with phylogeny. Gibbon vocalizations show hierarchical structures and song coordination behaviors, which may have different functions and convey distinct information compared to basic notes. However, previous studies have not compared vocalizations at multiple levels across species. We compared the vocal structures of three <i>Nomascus</i> species in the wild in South China, namely the western black gibbon (<i>Nomascus concolor</i>), Cao vit gibbon (<i>N. nasutus</i>), and Hainan gibbon (<i>N. hainanus</i>) at the levels of note (six features of four types of notes), male sequence (eight features), and song coordination (four features of the overlap pattern between male and female songs). We selected 15 recordings for each species: <i>N. concolor</i> (six groups, 2006 to 2021), <i>N. nasutus</i> (seven groups, 2008 to 2021), and <i>N. hainanus</i> (six groups, 2020 to 2021). We used permuted random forest analysis to test for species differences in vocal structure and the contribution of acoustic features to species differences at each level. We used acoustic features to construct a hierarchical clustering tree, and compared it with phylogenetic relationships. We found significant differences at all levels except the boom note. Acoustic similarity did not match genetic similarity in boom and pre-modulated notes, suggesting that genetic differences are not the only factor leading to species differences in vocal structures. We also found different contributions of acoustic features to differentiation in vocal structure at different levels. Our study suggests that we need to compare gibbon vocalizations at different levels to understand their differentiation and evolution.</p>","PeriodicalId":14264,"journal":{"name":"International Journal of Primatology","volume":"57 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141934693","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Brown Lemur (Eulemur spp.) Use of Olfaction, Memory, and Social Strategies to Obtain Cantaloupe","authors":"Elena P. Cunningham, Malvin N. Janal, Rachelle Wolk, Maria Gonzalez-Robles","doi":"10.1007/s10764-024-00448-0","DOIUrl":"https://doi.org/10.1007/s10764-024-00448-0","url":null,"abstract":"<p>The ability of primates to make decisions by integrating sensory information, memories about their environment, and social factors may have played a role in the evolution of primate cognition. However, we know little about the ability of lemurs to consider multiple aspects of a problem. We conducted experiments on the use of memory and olfaction in 11 groups of captive brown lemurs (<i>Eulemur</i> spp). We placed six or nine containers, 1/3 of which we baited with two pieces of cantaloupe, in consistent locations in the lemurs’ enclosures. We used two schedules for five initial trials, with delays of 2 h or 1 day (i.e., with nocturnal sleep) between trials. We conducted subsequent trials after 1, 2, 4, 5, 7, and 14 days. We recorded the order in which lemurs investigated and opened containers. We also noted social interactions, scent marking, and the number of pieces of cantaloupe eaten. The probability that lemurs would investigate baited containers before empty containers increased from chance levels on the first trial to approximately 0.5 above chance by the 6th and later trials, indicating the use of memory. The initial schedule did not significantly affect performance. Lemurs opened 98% (273 of 278) of baited containers before empty containers, indicating the use of olfaction at close range. They scent-marked in the proximity of only 10% of baited containers. Dominant status and being first to investigate baited containers positively impacted cantaloupe consumption. The results suggest that the lemurs integrated spatial memory, olfactory cues, and social information in decision-making.</p>","PeriodicalId":14264,"journal":{"name":"International Journal of Primatology","volume":"56 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141866614","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mandrill (Mandrillus sphinx) Presence in Southeast Cameroon Confirmed By Camera Traps and Indigenous Knowledge","authors":"Shun Hongo, Zeun’s Célestin Brice Dzefack, Valdeck Virgie Mopo Diesse, Marcel Armel Nyam Anong, Kaori Mizuno, Yukiko Hiroshima, Champlain Djiéto-Lordon, Hirokazu Yasuoka","doi":"10.1007/s10764-024-00451-5","DOIUrl":"https://doi.org/10.1007/s10764-024-00451-5","url":null,"abstract":"<p>Determining primate geographic ranges is essential for understanding their ecology and developing their conservation policies, but it is particularly challenging for rare, cryptic, or widely distributed species. Science-based methods and Indigenous and local knowledge have mutually contributed to addressing this conundrum. Here, we report on a new camera-trap record of a solitary mandrill (<i>Mandrillus sphinx</i>) in Nki National Park, southeast Cameroon, and interviews with Baka people about encounters with mandrills. We placed 481 camera traps for 32,644 total days, obtaining one video of an adult male mandrill on 19 April 2021, 20.2 km north of the Dja River. We also interviewed 30 Baka people from two neighboring villages about their experiences of observing mandrills. Seven interviewees responded that they had observed mandrills in this area: three reported solitary males, and four reported large groups. All observations were in areas &gt;30 km south of the villages and &gt;20 years ago. The results suggest the presence, but also the rarity, of mandrills in this area, where only solitary males may range outside the species geographic distribution, possibly temporarily. However, we cannot conclude that large groups of mandrills are absent in this area because people are not allowed to stay in the park, so the Baka people’s knowledge of the remote areas has been severely limited. To determine the accurate distribution of primates and develop effective conservation actions, we need collaborative research and conservation platforms that further connect Indigenous and local people with scientists.</p>","PeriodicalId":14264,"journal":{"name":"International Journal of Primatology","volume":"151 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141866611","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Adaptive Role of Bark in the Diet of Budongo Chimpanzees (Pan troglodytes schweinfurthii)","authors":"E. Freymann, G. Badihi, C. Hobaiter, M. A. Huffman, G. Muhumuza, S. Orbell, D. Sempebwa, E. Robert Yikii, K. Zuberbühler, S. Carvalho","doi":"10.1007/s10764-024-00445-3","DOIUrl":"https://doi.org/10.1007/s10764-024-00445-3","url":null,"abstract":"<p>The ingestion of bark has been observed across the animal kingdom and is well documented in free-ranging chimpanzees. Thus far, the best-supported hypothesis for the adaptive function of this behavior is the fallback food hypothesis, which asserts that chimpanzees consume bark and cambium when preferred foods are scarce. However, alternative explanations exist, including the <i>essential nutrient and mineral hypothesis</i>, the <i>self-medication hypothesis</i>, and the <i>stressed-tree hypothesis</i>. We tested whether the fallback food hypothesis can explain bark-feeding across two communities of Eastern chimpanzees (<i>Pan troglodytes schweinfurthii</i>) in the Budongo Forest, Uganda. We used 13 years of the site’s long-term behavioral data, 5 years of food availability data, and 8 months of direct and indirect observations. We also conducted eight 400-m line transects to collect data on the distribution of tree species across community home ranges. We employed several analyses, including Pearson correlation tests, qualitative comparisons of descriptive data and heat maps, and interpretation of behavioral anecdotes. We found varying patterns of bark-feeding seasonality across tree species, with bark-feeding on several species showing no correlation with food scarcity. We also identified differences in the amounts of bark targeted between tree species and report anecdotal evidence of chimpanzees prioritizing bark over high-value foods. Lastly, we found that bark-feeding on certain species disproportionally occurs far from community core areas, despite relative abundance of these species within the home range. As a result, we argue that the fallback food hypothesis cannot explain bark-feeding across all tree species. Instead, we present supporting evidence for several alternative hypotheses, including self-medication, thereby challenging the widely accepted function of this behavior.</p>","PeriodicalId":14264,"journal":{"name":"International Journal of Primatology","volume":"15 1 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141550734","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sleeping Site Selection, Sleep-related Positional Behavior, and Social System of Philippine Tarsiers (Carlito syrichta) Inhabiting a Protected Forest Fragment in Mindanao Island, Philippines","authors":"Simeon Gabriel F. Bejar, Danah Marie P. Purificacion, Lemnuel V. Aragones, Marilyn M. Balais, Anna Pauline O. de Guia, Melizar V. Duya, Perry S. Ong, Mariano Roy M. Duya","doi":"10.1007/s10764-024-00443-5","DOIUrl":"https://doi.org/10.1007/s10764-024-00443-5","url":null,"abstract":"<p>Sleep and sleep-related behaviors are integral components of primate behavior and ecology that are linked to various habitat-specific factors and often are modified in response to environmental fluctuations and threats. Despite the growing literature on primates, information on sleep-related behaviors of tarsiers remains sparse, especially for Philippine tarsiers, where our current understanding is hampered by the paucity of studies on wild populations. We radio-tracked eight Philippine tarsiers inhabiting a protected forest fragment between December 2016 and February 2018 to assess their sleeping site selection, sleep-related positional behavior, and social system. From 266 instantaneous sampling bouts, where each tarsier was observed a maximum of once per day, we found that the tarsiers frequently used trees with thickets of lianas and at least 15 plant species as sleeping sites. They slept from ground level to above 8 m, with most sightings at 3 to 6 m, and recurrent detections above 8 m, and preferred a flexed resting posture, on angled or horizontal, small-sized lianas or branches. Although frequently solitary, they also slept in pairs and in small groups of up to four individuals. We inferred polygyny based on observations of one adult male who associated and huddled with two nonassociated adult females, and direct male care through huddling and accompaniment. Our study revealed increased height use and gregariousness not previously described for Philippine tarsiers, shedding light on potential flexible behaviors by nocturnal primates in fragmented landscapes. Sleep-related behaviors present another avenue of research that has important implications on their conservation.</p>","PeriodicalId":14264,"journal":{"name":"International Journal of Primatology","volume":"24 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141550612","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Occupancy of Sympatric Central Chimpanzee (Pan troglodytes troglodytes) and Western Lowland Gorilla (Gorilla gorilla gorilla) in Campo Ma’an Conservation Area, Southern Cameroon","authors":"Emily Collins, Robert B. Weladji","doi":"10.1007/s10764-024-00446-2","DOIUrl":"https://doi.org/10.1007/s10764-024-00446-2","url":null,"abstract":"<p>Sympatric primate species coexist in tropical communities through interactions with the abiotic environment and other species. Determining the factors that influence primate species co-occurrence can help to inform conservation practices. Our study focused on the ecological interactions of central chimpanzees (<i>Pan troglodytes troglodytes</i>) and western lowland gorillas (<i>Gorilla gorilla gorilla</i>) with each other and their environment in a multiuse landscape. We assessed species-specific occupancy at 17 camera trap sites across different land-use types (National Park, Forest Management Units, or Community Lands) between June 2019 and May 2020 and examined the impact of fruit availability and human presence on ape presence. Across the study area, chimpanzees occupied a greater total number of sites than did gorillas, with a significantly higher proportion of occupied sites within the National Park than in other land-use types. The density of fruiting trees positively influenced the presence of gorillas but had no effect on chimpanzee presence. We found no effect of human presence on the presence of either chimpanzees or gorillas, although this analysis was limited to sites where apes were present. The probability of either species being present at a site during a given month remained stable under the conditional presence or absence of the other species, suggesting the absence of interactions between the two species at our study sites. These results support previous findings that the heterogeneous distribution of fruits and preferred resources allows chimpanzees and gorillas to limit direct competition by exploiting different feeding resources. Our findings provide insights on the factors influencing the occupancy of each species, including environmental variables and land-use type, information relevant when monitoring their coexistence within tropical communities.</p>","PeriodicalId":14264,"journal":{"name":"International Journal of Primatology","volume":"7 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141550614","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Population Viability and Genetic Structure of the Last Remaining Population of the Critically Endangered Gray Snub-Nosed Monkey (Rhinopithecus brelichi)","authors":"Yanqing Guo, Paul A. Garber, Renbao Ping, Jiang Zhou","doi":"10.1007/s10764-024-00447-1","DOIUrl":"https://doi.org/10.1007/s10764-024-00447-1","url":null,"abstract":"<p>Habitat destruction, land conversion, and forest fragmentation over the past several decades have resulted in major declines and local extirpation of wild animal and plant species. The gray snub-nosed monkey (<i>Rhinopithecus brelichi</i>) is currently listed among the 25 most endangered primate species in the world, with an estimated remaining wild population of less than 400 individuals. Given the potential negative effects of small population size on genetic diversity, we investigated how factors, such as climate, inbreeding, kinship, population structure, and effective population size, have contributed to their genetic status. We extracted DNA from 307 fecal samples and analyzed microsatellite diversity, sex-identifying genes, and the mtDNA control region in 179 wild individuals. Our analyses suggest that gray snub-nosed monkeys experienced an initial population decline during the Last Glacial Maximum, some 20,000 years ago. During the past 70 years, this species experienced a second, steeper population decline, coinciding with human activities. Their current effective population size (± SD) of 675 ± 292 exceeds the remaining number of individuals in the population and has declined by 93.9%—96.7% over the past 20,000 years. Our findings highlight the need for immediate conservation and management strategies to protect this endemic and Critically Endangered primate species.</p>","PeriodicalId":14264,"journal":{"name":"International Journal of Primatology","volume":"47 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141550632","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}