International Journal of Primatology最新文献

{"title":"On the Phylogenetic History of the Sanje Mangabey (<i>Cercocebus sanjei</i>), Udzungwa Mountains, Tanzania.","authors":"Christina Lynette Paddock, Maria Joana Ferreira da Silva, Gráinne Michelle McCabe, David Fernández, William Scott McGraw, Michael William Bruford","doi":"10.1007/s10764-026-00559-w","DOIUrl":"10.1007/s10764-026-00559-w","url":null,"abstract":"<p><p>An accurate understanding of phylogeny, including intraspecific diversity, is key for defining conservation measures. The Sanje mangabey (<i>Cercocebus sanjei</i>) is an Endangered primate endemic to the Udzungwa Mountains in Tanzania that inhabits montane forest fragments and occurs in two populations-Mwanihana Forest and Uzungwa Scarp Nature Reserve-located 100 km apart. The phylogenetic position of the Sanje mangabey relative to other <i>Cercocebus</i> species remains unclear. We aimed to clarify the phylogeny of the Sanje mangabey and estimate its divergence time from other species. We reconstructed phylogenies using nuclear (CD4 and TSPY) and mitochondrial (COII and control region) sequences in noninvasive DNA sampled from both the populations (n = 88 sequences). We found that the Sanje mangabey grouped with the central/East African mangabeys (<i>C. galeritus</i>, <i>C. chrysogaster</i>, and <i>C. agilis</i>) and estimated that it diverged from the common ancestor ~2.34 million years ago (MYA; 95% Highest Probability Density (HPD) interval: 1.73-2.95 MYA). Results suggest that the two extant Sanje mangabey populations represent distinct lineages, diverging 0.77 MYA (95% HPD interval: 0.43-1.15 MYA). This divergence and isolation into two montane forest fragments may be attributed to increasing aridification in eastern Africa beginning ~2.6 MYA, the formation of physical barriers to dispersal and competition with other species. By confirming the evolutionary distinctiveness of the Sanje mangabey relative to other <i>Cercocebus</i> species, this study highlights the need for dedicated conservation management policies. Such policies should also consider the two populations as candidate evolutionary significant units. Further morphological, genetic, and behavioural studies are needed to assess the extent of reproductive isolation in Sanje mangabeys. Our study highlights the need to identify cryptic diversity within threatened species in order to improve their conservation.</p><p><strong>Supplementary information: </strong>The online version contains supplementary material available at 10.1007/s10764-026-00559-w.</p>","PeriodicalId":14264,"journal":{"name":"International Journal of Primatology","volume":"47 3","pages":"842-867"},"PeriodicalIF":1.3,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13348350/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148421026","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hair Steroid Signatures of Cooperative Breeding in Male and Female Common Marmosets (<i>Callithrix jacchus</i>).","authors":"Benjamin N Laubi, Gaëtan Glauser, Erik P Willems, Carel P van Schaik, Judith M Burkart","doi":"10.1007/s10764-026-00568-9","DOIUrl":"10.1007/s10764-026-00568-9","url":null,"abstract":"<p><p>Cooperative breeding presents social and reproductive challenges that differ from those associated with independent breeding, but its endocrine correlates are not well understood. We investigated cumulative steroid hormone profiles in common marmosets (<i>Callithrix jacchus</i>), a primate species characterized by shared caregiving and clearly defined reproductive roles between primary breeders and non-breeding helper group members. Using high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) on hair samples, we simultaneously quantified six steroid hormones across 71 individuals varying in breeding role, sex, age, and group reproductive context. Glucocorticoids were highest in breeder females, declined with age, and were higher in breeders when dependent offspring were present. Testosterone showed a comparatively modest male-female difference and was positively associated with the presence of dependent offspring in breeders, whereas androstenedione closely paralleled testosterone across age, consistent with shared regulation. Ovarian steroids showed clear sex differentiation in progesterone, with markedly elevated levels in breeder females, whereas estradiol differences were smaller, emerging as a modest sex effect within breeders and an age effect in helpers. Together, these findings highlight weaker sexual dimorphism in sex hormone profiles than often reported for independently breeding primates. They also reveal hormonal signatures of stress and vigilance related to caregiving, consistent with cooperative breeding in marmosets. Our study demonstrates the value of hair for long-term hormonal assessment and underscores the utility of HPLC-MS/MS for quantifying multiple hormones with high specificity in socially complex primates.</p><p><strong>Supplementary information: </strong>The online version contains supplementary material available at https://doi.org/10.1007/s10764-026-00568-9.</p>","PeriodicalId":14264,"journal":{"name":"International Journal of Primatology","volume":"47 4","pages":"988-1014"},"PeriodicalIF":1.3,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13661722/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149181573","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Intergroup Encounters Among Wild White-Faced Capuchins (<i>Cebus imitator</i>) at a Densely Populated Field Site: Insights into Frequency, Intensity, and Participation.","authors":"Sarah A Kovalaskas, Agostina Colosimo, Vasco Alexandre Martins, Juan Carlos Ordoñez, Elena Morera Saborío, Jacinta C Beehner, Thore J Bergman, Marcela E Benítez","doi":"10.1007/s10764-026-00548-z","DOIUrl":"10.1007/s10764-026-00548-z","url":null,"abstract":"<p><p>Intergroup encounters (IGEs) are a major feature of social life for group-living primates, influencing access to resources, reproductive opportunities, and territory. We examined IGE frequency, intensity, and participation in a high-density population of wild white-faced capuchin monkeys (<i>Cebus imitator</i>) at the Capuchinos de Taboga research project in Guanacaste, Costa Rica, using 4 years of data on three capuchin groups (4,984 observation hours, 218 IGEs). The IGE rates at Taboga (0.044/hr) were two to four times higher than those at nearby lower-density sites and did not vary with rainfall or temperature. More than half of IGEs involved high-intensity aggression (chases or contact aggression). Ordinal logistic models showed that the number of focal group participants was a consistent predictor of escalation, with each additional participant increasing the odds of higher intensity by 1.4 times, while ecological variables had little explanatory value. Participation was more likely for older individuals, males, alphas, and when individuals were closer to the center of core use areas; males participated more than females at distances further from the center of core use areas. Females participated in 44% of IGEs, with lactating females less likely to participate than cycling or pregnant females. Our findings suggest that high population density and overlapping ranges drive frequent and aggressive IGEs at Taboga and that escalation is shaped primarily by social rather than ecological factors. These results highlight the importance of social processes in territorial defense and underscore their role in shaping intergroup conflict in areas of high population density.</p><p><strong>Supplementary information: </strong>The online version contains supplementary material available at 10.1007/s10764-026-00548-z.</p>","PeriodicalId":14264,"journal":{"name":"International Journal of Primatology","volume":"47 3","pages":"616-640"},"PeriodicalIF":1.3,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13323443/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148375698","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Loud Call Production in Male Vervet Monkeys (<i>Chlorocebus pygerythrus</i>) Varies with Season and Signaller Rank.","authors":"Lukas Schad, Pooja Dongre, Erica van de Waal, Julia Fischer","doi":"10.1007/s10764-024-00475-x","DOIUrl":"https://doi.org/10.1007/s10764-024-00475-x","url":null,"abstract":"<p><p>Adult males of many nonhuman primate species utter characteristic loud calls that are audible over long distances and serve various functions. In response to large terrestrial predators, male vervet monkeys (<i>Chlorocebus pygerythrus</i>) produce loud 'barks' that alert group members and are assumed to deter predators. It is less well known that male vervet monkeys also produce barks during aggressive interactions within and between groups. Here, we investigated whether barks potentially serve a dual function as alarm calls and quality signals. We used ad-libitum event sampling to record natural barking events from 45 adult males in six free-ranging groups over 24 months at Mawana Game Reserve, KwaZulu-Natal, South Africa. For each barking event in groups with multiple males, we aimed to record whether each adult male in the group barked or not. Using generalised linear mixed models, we investigated whether the number of barking events recorded per observation day and the probability that an individual male barked in each event were associated with male rank, the number of males in the group, the adult sex ratio, and the mating season. The highest-ranking males showed a very high probability of barking, and the number of daily barking events increased during the mating season. Males frequently barked in aggressive interactions, supporting the hypothesis that this signal plays a role in male-male competition. We conclude that, in addition to serving as alarm calls, barks may also advertise male competitive ability or motivation to compete.</p><p><strong>Supplementary information: </strong>The online version contains supplementary material available at 10.1007/s10764-024-00475-x.</p>","PeriodicalId":14264,"journal":{"name":"International Journal of Primatology","volume":"46 2","pages":"538-555"},"PeriodicalIF":1.9,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12045810/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144017148","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mixed-Species Groups and Genetically Confirmed Hybridization Between Sympatric Phayre’s Langur (Trachypithecus phayrei) and Capped Langur (T. pileatus) in Northeast Bangladesh","authors":"Tanvir Ahmed, Sabit Hasan, Shimul Nath, Sajib Biswas, Atikul Islam Mithu, Harish Debbarma, Rasel Debbarma, Khurshed Alom, Auritro Sattar, Tania Akhter, Mahmudul Bari, Abu Bakar Siddik, Sabir Bin Muzaffar, Dietmar Zinner, Christian Roos","doi":"10.1007/s10764-024-00459-x","DOIUrl":"https://doi.org/10.1007/s10764-024-00459-x","url":null,"abstract":"<p>Interspecific hybridization occurs almost in all major primate radiations. Intermediate phenotypes, sometimes seen in mixed-species groups, are often the first indications of hybridization. Beyond natural hybridization, human activities, such as habitat fragmentation or population depletion, can be important drivers for initiating or intensifying the formation of mixed-species groups and hybridization. As hybridization can lead to the cyto-nuclear extinction of species, it may pose additional threats to threatened primates. To assess the frequency of mixed-species groups and intermediate phenotypes between threatened Phayre’s (<i>Trachypithecus phayrei</i>) and capped langurs (<i>T. pileatus</i>), we conducted population surveys in six forests of northeast Bangladesh between 2018 and 2023. We also tested the hybrid status of one individual with intermediate phenotype genetically, by sequencing the maternally-inherited mitochondrial cytochrome b gene and fragments of two biparentally-inherited loci. During our surveys, we encountered 98 groups of langurs of which 41 were Phayre’s langur groups, 49 capped langur groups, and eight mixed-species groups (8%). In three mixed-species groups, we detected three individuals of intermediate phenotype, among them one adult female whose nipples were elongated indicating that she had an infant, and thus was likely to be fertile. Genetic analyses confirmed the hybrid status (most likely F1) of one individual with intermediate phenotype. To our knowledge, there are no reports of mixed-species groups and hybridization from other parts of the range where the species occur sympatrically. Hence, it seems likely that such groups occur mainly in the northern part of their common range where natural habitats are deteriorating fast. Therefore, we suggest monitoring of the populations, to find out whether the frequency of mixed-species groups increases, and a large-scale population genetic study to investigate whether hybridization is a recent phenomenon or occurred historically in the zone of range overlap in Bangladesh.</p>","PeriodicalId":14264,"journal":{"name":"International Journal of Primatology","volume":"10 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142247606","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":"Examining the Long-term Retention of Associative Stimulus Relations in Chimpanzees (Pan troglodytes)","authors":"Sou Ueda, Masaki Tomonaga","doi":"10.1007/s10764-024-00456-0","DOIUrl":"https://doi.org/10.1007/s10764-024-00456-0","url":null,"abstract":"<p>Humans can retain memories for months to decades. In contrast, relatively few studies have examined such very long-term memory in nonhuman animals. We, therefore, investigated whether chimpanzees (<i>Pan troglodytes</i>) who had learned arbitrary relations between stimuli remembered these relations over a long period. In Experiment 1, we tested four chimpanzees, one of whom (Chloe) had learned a “symbolic” matching task between colors and geometric forms at age 9–10 years, and three who had not been previously trained, on their memory for these relations 19 years later. Chloe showed perfect accuracy in the test trials; the three other chimpanzees did not perform better than chance level. In Experiment 2, we tested Popo and Reo, who had learned the same set at the same time as Chloe, on their memory 27 years later. Although they relearned the identity-matching task very quickly (savings effect), they did not retain the stimulus relations learned 27 years ago. In Experiment 3, we tested Chloe’s retention of a different set of stimulus relations, which she had learned at the same time as those tested in Experiment 1 but with less intensive training than with the first set. She did not perform better than the chance level. Finally, in Experiment 4, we tested the memory retention of another chimpanzee, Ai, who had learned to “label” objects with lexigrams more than 20 years earlier by using the matching task. She did not perform significantly better than chance on test trials. Thus, our results were not consistent across the experiments, providing only limited evidence that chimpanzees retain associative stimulus relations over the long term. Several factors, such as the effect of cognitive environments, the levels of processing, and the context-dependent nature of memory retrieval, could have affected our results, but none of these factors can account for all the results from the four experiments.</p>","PeriodicalId":14264,"journal":{"name":"International Journal of Primatology","volume":"28 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142247607","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":"Obituary: Michelle Bezanson—Teacher-Scholar, Artist, Advocate (1968–2024)","authors":"Erin P. Riley","doi":"10.1007/s10764-024-00460-4","DOIUrl":"https://doi.org/10.1007/s10764-024-00460-4","url":null,"abstract":"","PeriodicalId":14264,"journal":{"name":"International Journal of Primatology","volume":"75 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142191086","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":"No Evidence for a Link Between Dominance Rank, Unit Size, and Faecal Glucocorticoid Levels in a Small Sample of Wild female Guinea Baboons (Papio papio)","authors":"Adeelia Goffe, Carolin Niederbremer, Michael Heistermann, Julia Fischer, Federica Dal Pesco","doi":"10.1007/s10764-024-00458-y","DOIUrl":"https://doi.org/10.1007/s10764-024-00458-y","url":null,"abstract":"<p>In response to environmental and social challenges, animals mount physiological “stress responses” involving elevated glucocorticoid (GC) levels, which may have long-term consequences for health and survival. However, the degree to which social factors drive these physiological responses is likely modulated by a species’ social system, including social organisation, dispersal patterns, and the steepness of the dominance hierarchy, which influence the costs and benefits of social interactions. We examined the relationship between dominance rank, unit size, and faecal GC metabolite (fGC) levels in wild female Guinea baboons (<i>Papio papio</i>). Guinea baboons live in multilevel societies with female-biased dispersal and shallow rank relationships. Units consisting of one primary male and associated females form the core of these societies. We hypothesised that females experience higher competition for male protection or access to food in larger units and that lower-ranking females would bear the costs of this competition. We predicted that membership in a larger unit and lower rank would be associated with higher fGC levels. We collected 251 faecal hormone samples from 14 individuals. A capture event during the sampling period allowed us to validate our method's sensitivity to stress responses. However, we found no evidence of a link between unit size or rank and fGC levels, suggesting that neither incurs a significant physiological cost in this species. These results extend our insights into the physiological correlates of behavioural variation in female primates, expanding our understanding of their adaptability and resilience to social stressors in relatively egalitarian multilevel societies with female-biased dispersal.</p>","PeriodicalId":14264,"journal":{"name":"International Journal of Primatology","volume":"7 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142191095","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":"Genital Wounding in Chimpanzees (Pan troglodytes): Targeted Attacks or Happenstance?","authors":"Anthony P. Massaro, Elizabeth V. Lonsdorf, Dismas Mwacha, Melissa Emery Thompsom, Zarin Machanda, Jill Pruetz, Kathelijne Koops, Stefano Kaburu, Michael L. Wilson","doi":"10.1007/s10764-024-00454-2","DOIUrl":"https://doi.org/10.1007/s10764-024-00454-2","url":null,"abstract":"<p>Reports of primate violence frequently note wounds to the genital region, raising the possibility that attackers target genitals to eliminate the reproductive capacity of rivals. Alternatively, in chimpanzees (<i>Pan troglodytes</i>) and other species with prominent genitals, injuries may occur simply because large size makes genitals easy targets. To test these hypotheses, we compiled records of wounds suffered by chimpanzees in four communities at three long-term study sites (Gombe, Tanzania; Kibale, Uganda; Fongoli, Senegal), including both nonlethal (N = 1,268 wounds; N = 891 male wounds; N = 377 female wounds) and lethal attacks (N = 258 wounds), to determine whether genital wounding occurred more frequently than expected by chance. In nonfatal cases, wounds occurred in the genital region more often than expected for females (Kasekela: N = 9/80 wounds, Mitumba: N = 8/61 wounds, Fongoli: N = 11/84 wounds, Kanyawara: N = 31/152 wounds), but only in Kasekela did males suffer genital wounds more often than expected by chance (Kasekela: N = 3/80 wounds, Mitumba: N = 2/48 wounds, Fongoli: N = 6/413 wounds, Kanyawara: N = 4/350 wounds). In contrast, killings of males involved genital wounds more often than expected (N = 12/258 wounds). Increased genital wounding may occur when genitals are more accessible, such as when females flee from male aggression, exposing their hindquarters, or when victims are immobilized during fatal attacks.</p>","PeriodicalId":14264,"journal":{"name":"International Journal of Primatology","volume":"40 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142191106","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":"Bridging Species Divides: Affiliative Interactions between Theropithecus gelada and Papio anubis in an Unprotected Area in Ethiopia","authors":"Alice Galotti, Martina Francesconi, Luca Pedruzzi, Sheleme Abiyou Gamessa, Alban Lemasson, Bezawork Afework Bogale, Elisabetta Palagi","doi":"10.1007/s10764-024-00450-6","DOIUrl":"https://doi.org/10.1007/s10764-024-00450-6","url":null,"abstract":"","PeriodicalId":14264,"journal":{"name":"International Journal of Primatology","volume":"395 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142191096","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}