American Journal of Primatology最新文献

{"title":"Sexual Signaling and Sociosexual Behaviors in Relation to Rank, Parasites, Hormones, and Age in Male Vervet Monkeys (Chlorocebus pygerythrus) in Uganda","authors":"Karin P. Snyder,&nbsp;Dina Greenberg,&nbsp;Taylor Fane,&nbsp;Alessandro Filazzola,&nbsp;Gabriela F. Mastromonaco,&nbsp;Valérie A. M. Schoof","doi":"10.1002/ajp.23711","DOIUrl":"10.1002/ajp.23711","url":null,"abstract":"<p>Secondary sexual characteristics, and the extent to which they are expressed, can convey information about the signaller. The blue scrotum and red penis of male vervet monkeys (<i>Chlorocebus pygerythrus</i>) make them a good species in which to examine inter- and intramale variation in signal expression. We quantified genital hue and luminance of male vervets at Lake Nabugabo, Uganda from standardized photos of male genitalia taken in May to June 2016, January to March 2019, and April to June 2019 to examine how dominance rank, fecal androgens (fARMs), fecal glucocorticoids (fGCMs), and parasitism related to achromatic (i.e., luminance) and chromatic (i.e., hue) aspects of scrotal and penile coloration, as well as how genital color related to sociosexual behaviors. We examined 182 photoshoots, 214 fecal samples for hormone analyses, and 152 for parasite analyses. Linear models indicate that genital color is linked to male dominance rank; high-ranking males had a more luminant (i.e., brighter) scrotum and a redder penis. Within males, color characteristics remained relatively stable over the short-term and changed moderately over the long-term. The direction of change was inconsistent for all color characteristics except scrotal luminance, which increased in all males over the long-term. Males with a darker penis received more mating presentations, while higher-ranking males received more mating refusals than low-ranking males, suggesting that females pay attention to penile color. We did not find support for any parasite or hormone mediation of color, and while there was a correlation between fGCM and fARMs, this was positive rather than negative as predicted by the stress-linked immunocompetence handicap hypothesis. Overall, our results indicate that the production of genital color may serve as an intra- and/or intersexual signal of male dominance rank and age in vervets.</p>","PeriodicalId":7662,"journal":{"name":"American Journal of Primatology","volume":"87 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11666871/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142881116","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":"The Influence of Provisioning on the Intergroup Relationships of Rhesus Macaque in Hainan, China","authors":"Cheng-Feng Wu,&nbsp;Zhi-Hong Xu,&nbsp;Yu-Xuan Fan,&nbsp;Tao Chen,&nbsp;Pu-Zhen Xie","doi":"10.1002/ajp.23721","DOIUrl":"10.1002/ajp.23721","url":null,"abstract":"<div>\u0000 \u0000 <p>Intergroup competition for limited resources is a significant selection pressure that drives the evolution of animal society. The rhesus macaque (<i>Macaca Mulatta</i>) is the most widely distributed nonhuman primate in the world and can adapt well to environments disturbed by humans. In some areas, human provisioning provides ample food resources for rhesus macaques, leading to an increase in their population size, inevitably affecting competition patterns within and between groups. In this study, we focused on seven provisioned groups of rhesus macaque in an eco-tourism park in Hainan, China, to verify how provisioning impacted their intergroup relationships. The results showed that: (1) Peaceful coexistence was the most common form of Intergroup contacts; (2) Provisioning led to an increase in intergroup contact and conflicts, but monkeys tended to avoid direct contact with other groups at main-provisioned sites with high conflict risk. (3) Larger groups did not interfere with each other's space use in the park, but smaller groups were more easily tolerated by other groups. (4) There were no strict linear dominance relationships among monkey groups. Overall, intensive provisioning satisfied the energy requirement of all monkeys in our study site, leading to a reduction in the relative benefit of intergroup conflict. Consequently, monkeys have adopted an intergroup contact strategy that avoids direct conflicts and prevents conflict escalation. We should pay more attention to the behavior patterns of provisioned animal populations, which will help us better understand how resources such as food have influenced the evolution of social strategies of animal groups, as well as how to manage such human disturbed animal populations in the future.</p>\u0000 </div>","PeriodicalId":7662,"journal":{"name":"American Journal of Primatology","volume":"87 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142881118","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":"Placental and Fetal Microbiota in Rhesus Macaque: A Case Study Using Metagenomic Sequencing","authors":"Qiao Du,&nbsp;Xu Liu,&nbsp;Rusong Zhang,&nbsp;Gang Hu,&nbsp;Qinghua Liu,&nbsp;Rui Wang,&nbsp;Wen Ma,&nbsp;Ying Hu,&nbsp;Zhenxin Fan,&nbsp;Jing Li","doi":"10.1002/ajp.23718","DOIUrl":"10.1002/ajp.23718","url":null,"abstract":"<div>\u0000 \u0000 <p>Recent evidence challenging the notion of a sterile intrauterine environment has sparked research into the origins and effects of fetal microbiota on immunity development during gestation. Rhesus macaques (RMs) serve as valuable nonhuman primate models due to their similarities to humans in development, placental structure, and immune response. In this study, metagenomic analysis was applied to the placenta, umbilical cord, spleen, gastrointestinal tissues of an unborn RM fetus, and the maternal intestine, revealing the diversity and functionality of microbes in these tissues. Additionally, gut metagenomic data of adult Rhesus macaques from our previous study, along with data from a human fetus obtained from public databases, were included for comparison. We observed substantial microbial sharing between the mother and fetus, with the microbial composition of the placenta and umbilical cord more closely resembling that of the fetal organs than the maternal intestine. Notably, compared with other adult RMs, there was a clear convergence between maternal and fetal microbiota, alongside distinct differences between the microbiota of adults and the fetus, which underscores the unique microbial profiles in fetal environments. Furthermore, the fetal microbiota displayed a less developed carbohydrate metabolism capacity than adult RMs. It also shared antibiotic resistance genes with both maternal and adult RM microbiomes, indicating potential vertical transmission. Comparative analysis of the metagenomes between the RM fetus and a human fetus revealed significant differences in microbial composition and genes, yet also showed similarities in certain abundant microbiota. Collectively, our results contribute to a more comprehensive understanding of the intrauterine microbial environment in macaques.</p></div>","PeriodicalId":7662,"journal":{"name":"American Journal of Primatology","volume":"87 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142881103","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":"“Ontogenetic Scaling of the Primate Middle Ear”","authors":"Katheryn P. Franklin,&nbsp;Timothy D. Smith,&nbsp;Valerie B. DeLeon","doi":"10.1002/ajp.23710","DOIUrl":"10.1002/ajp.23710","url":null,"abstract":"<div>\u0000 \u0000 <p>The study of primate auditory morphology is a significant area of interest for comparative anatomists, given the phylogenetic relationships that link primate hearing and the morphology of these auditory structures. Extensive literature addresses the form-to-function relationship of the auditory system (outer, middle, and inner ear) in primates and, by extension, provides insight into the auditory system of extinct primates and even modern humans. We add to this literature by describing the ontogenetic trajectory of the middle ear cavity and ossicular chain (malleus, incus, and stapes) due to their critical role in relaying auditory stimuli for interpretation. We examined middle ear morphology in neonatal primates and adult primates using a taxonomically broad sample. We focused primarily on nocturnal primate taxa (<i>Daubentonia</i>, <i>Loris</i>, <i>Galago</i>, <i>Aotus</i>, and <i>Tarsier</i>), which are underrepresented in the literature. However, we also included three diurnal taxa (<i>Macaca</i>, <i>Lemur</i>, and <i>Saguinus</i>). Using 3D Slicer, we visualized middle ear structures in three dimensions using conventional micro CT data informed by diffusible iodine-based contrast-enhanced CT (diceCT) data. We illustrated how spatial relationships between otic elements, such as the various epitympanic sinuses of the middle ear and the auditory ossicles, vary throughout ontogeny. Our major findings include that the central tympanic cavity scaled with negative allometry in all taxa and that the accessory cavities scaled with isometry or positive allometry in most taxa. Despite these changes in chamber size, the size of the ear ossicles remained relatively consistent through ontogeny in most taxa. We confirmed our expectation that anthropoids exhibit an increase in the complexity of accessory cavities throughout ontogeny, mirroring the exponential pneumatization of the face in anthropoids. These findings provide an ontogenetic perspective and reveal further functional complexities of the middle ear as a conduit for sound proliferation and as a pressure regulator.</p></div>","PeriodicalId":7662,"journal":{"name":"American Journal of Primatology","volume":"87 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142863164","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":"Assessment of Suitable Habitats, Fragmentation Analysis, and Ecological Corridor Identification for Sichuan Golden Snub-Nosed Monkey (Rhinopithecus roxellana) in Sichuan Province, Southwest China","authors":"Yunchuan Dai,&nbsp;Yujing Zhu,&nbsp;Wancai Xia,&nbsp;Shuzhen Zou,&nbsp;Fan Wang,&nbsp;Dayong Li","doi":"10.1002/ajp.23714","DOIUrl":"10.1002/ajp.23714","url":null,"abstract":"<div>\u0000 \u0000 <p>The Sichuan golden snub-nosed monkey (<i>Rhinopithecus roxellana</i>) was found to possess significant scientific and conservation value but faced multiple threats including habitat fragmentation and loss, human disturbance, illegal hunting, and the impacts of climate change on their habitat. To enhance habitat protection for this species, our study utilized field survey data and distribution records from protected areas to systematically evaluate spatial heterogeneity in suitable habitat distribution and habitat quality in Sichuan Province. Integration of 3S technology and ecological modeling allowed for a comprehensive assessment. We found that: (1) The potential habitat area for the species in Sichuan Province covered 78,470.47 km², with suitable and marginally suitable habitats occupying 28,301.36 and 50,169.11 km² respectively. Suitable habitats were predominantly found at elevations of 1600–3200 m, in areas with low population density and minimal human disturbance. (2) Suitable habitats within protected areas accounted for 42.7% of the total suitable habitat area, while marginally suitable habitats within protected areas comprised 24.8% of the total marginally suitable habitat area. (3) Vegetation types most utilized by the species, ranked from highest to lowest preference, were deciduous broadleaf forests, evergreen coniferous forests, evergreen broadleaf forests, mixed coniferous-deciduous forests, and shrublands. Evergreen coniferous forests exhibited the largest patch area and lowest fragmentation, whereas deciduous broadleaf forests showed higher fragmentation within protected areas. (4) Four potential ecological corridors were identified, connecting the Wujiao, Xuebaoding, and Baodinggou nature reserves. Strengthening the protection of suitable habitats and potential ecological corridors would enhance landscape connectivity, facilitating the effective utilization of suitable habitats by the Sichuan golden snub-nosed monkey. Our findings provided a scientific basis for future conservation and management efforts for the Sichuan golden snub-nosed monkey.</p></div>","PeriodicalId":7662,"journal":{"name":"American Journal of Primatology","volume":"87 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142851590","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":"Novel Scent Enrichment Enhances Socio-Sexual and Olfactory Behaviors in Zoo-Housed Gentle Lemurs","authors":"Sara Fontani,&nbsp;Gale Glendewar,&nbsp;Rachel Cowen,&nbsp;Georgia Callagan,&nbsp;Anna B. Costantini,&nbsp;Emily Elwell,&nbsp;Colin Dubreuil,&nbsp;Matthew Palframan,&nbsp;Stefano Vaglio","doi":"10.1002/ajp.23716","DOIUrl":"10.1002/ajp.23716","url":null,"abstract":"<p>The Alaotran gentle lemur (<i>Hapalemur Alaotrensis</i>) is one of the most endangered primates in the world and shows a low success rate in captive breeding programmes. We tested a novel scent enrichment, made up of a synthesized mixture likely conveying information about female fertility, on four unsuccessful breeding pairs (<i>n</i> = 8 subjects) living at the Jersey, Birmingham, London (United Kingdom) and Mulhouse (France) zoos. We evaluated the effects of the scent enrichment on behavior (515 h of observation) and fecal endocrinology (cortisol and testosterone measurements) (<i>n</i> = 180 samples) comparing pre- enrichment, enrichment and post- enrichment phases. We found a small effect by sex on olfactory behaviors related to the enrichment. We also found that both male and female sexual behaviors significantly increased during the enrichment. Conversely, we did not find any significant change related to enrichment in cortisol and testosterone levels, whilst some effect by the zoo environment. Our results show little effectiveness by the scent enrichment as the lemur hormone levels did not change significantly and the lemurs continued to fail to reproduce following the enrichment. Nevertheless, our findings highlight that biologically relevant scent may trigger natural species-specific behaviors, with potential implications for enhancing behavioral health and management of zoo-based endangered lemur species.</p>","PeriodicalId":7662,"journal":{"name":"American Journal of Primatology","volume":"87 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajp.23716","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142851755","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":"The Lasting Impact of Social Isolation: Behavioral Insights From Former Pet and Entertainer Chimpanzees in a Sanctuary in Spain","authors":"Emma Chen,&nbsp;Giulia Pipolo,&nbsp;Dietmar Crailsheim,&nbsp;Juliano Morimoto","doi":"10.1002/ajp.23715","DOIUrl":"10.1002/ajp.23715","url":null,"abstract":"<p>Human fascination with chimpanzees has driven extensive research on the species, but also led to exploitation by private owners and entertainment industries. These animals often suffer species-specific inadequate conditions, which can result in the development and display of abnormal behaviors even after rescue. These behaviors highlight the importance for zoos and sanctuaries to actively prevent worsening the effects of previous inadequate treatment by providing apes with social and stimulating environments that support their recovery. We conducted a 2-month behavioral survey on two groups of former pet and entertainment chimpanzees (<i>n</i> = 10) at the Fundación MONA sanctuary in Spain. From 116 h of instantaneous scan observations, we documented individual abnormal behaviors (e.g., self-poking, overgrooming, self-scratching). We assessed the association between the occurrence of these behaviors and individuals' origin, early history, age at rescue, and pre-rescue social conditions. We found no significant difference in the frequency of abnormal behavior between pet and entertainer chimpanzees, and between individuals born in captivity versus in the wild. Moreover, we observed that the frequency of abnormal behaviors increased with age at rescue for previously isolated individuals, but the correlation disappeared for those socially housed pre-rescue. These findings suggest that early social isolation and a late age at rescue may impose long-term changes on chimpanzees' behavior, and they emphasize the importance of accounting for age at rescue and previous housing conditions in care management and rehabilitation procedures.</p>","PeriodicalId":7662,"journal":{"name":"American Journal of Primatology","volume":"87 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajp.23715","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142851787","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":"Potential of Japanese Macaques for Understanding Etiology and Seasonality of Repetitive Linear Enamel Hypoplasia in Nonhuman Primates","authors":"Mark Fretson Skinner,&nbsp;Mao Asami,&nbsp;Matthew M. Skinner,&nbsp;Akiko Kato","doi":"10.1002/ajp.23713","DOIUrl":"10.1002/ajp.23713","url":null,"abstract":"<p>Japanese macaques are ideal to advance understanding of a wide-spread pattern of recurrent developmental distress in great apes, preserved as repetitive linear enamel hypoplasia (rLEH). Not only are they numerous, unendangered, and well-studied, but they are distributed from warm-temperate evergreen habitats in southern Japan to cool-temperate habitats in the north, where they are adapted behaviorally and phenotypically to winter cold and seasonal undernutrition. We provide a pilot study to determine if enamel hypoplasia exists in Japanese macaques from the north and, if temporal patterns of enamel hypoplasia are consistent with seasonal cold, undernutrition and/or exposure to secondary plant compounds. High-resolution casts of canine teeth from 15 males obtained from Shimokita Peninsula (latitude 41.3° N) between 2012 and 2014, whose skeletons are curated at the Center for the Evolutionary Origins of Human Behavior, Kyoto University, were imaged by confocal and scanning electron microscopy. Perikymata, the surface expression of regularly deposited imbricational layers of enamel, provide an estimate of time between and within hypoplastic enamel defects. Based on histological sections from five individuals, we determined Retzius periodicity to be 7 days. Evidence for recurrence, duration, and severity of 68 LEH defects was collected from perikymata counts as well as measurements of LEH angle of onset, depth and width. Male canine teeth show four to five recurrent, evenly-spaced enamel defects per crown with a median of 54.8 (range 18–74) perikymata between defects; lasting on average 8.7 (range 1–20) perikymata. These translate into repetitive developmental distress averaging every 1.05 years, lasting 8.7 weeks, less than local winter foraging conditions (100 days). We conclude that linear enamel hypoplasia recurs circ-annually among high-latitude male monkeys from Japan. The triad of cold, hunger and anti-feedants can be differentiated in future study through recourse to provisioned and un-provisioned populations throughout the Japanese archipelago.</p>","PeriodicalId":7662,"journal":{"name":"American Journal of Primatology","volume":"87 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajp.23713","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142845624","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":"Morphometric Study on the Mandible of Colobine Fossil (Mesopithecus pentelicus) Found in East Asia, a Comparison With Extant Taxa","authors":"Hao Pan,&nbsp;Xueping Ji,&nbsp;Dionisios Youlatos,&nbsp;Ying Chen,&nbsp;He Zhang,&nbsp;Gaigai Guo,&nbsp;Jing Wang,&nbsp;Kang Huang,&nbsp;Rong Hou,&nbsp;Gang He,&nbsp;Songtao Guo,&nbsp;Pei Zhang,&nbsp;Baoguo Li,&nbsp;Ruliang Pan","doi":"10.1002/ajp.23706","DOIUrl":"10.1002/ajp.23706","url":null,"abstract":"<div>\u0000 \u0000 <p>A tooth-bearing mandible fossil of a colobine monkey discovered at Shuitangba, Zhaotong, Yunnan, China, was morphometrically analyzed and compared with extant Asian colobines. Our previous qualitative and quantitative descriptions indicate that it can be safely attributed to <i>Mesopithecus pentelicus</i>, a Miocene fossil colobine widely found in Europe and South Asia. The present research aims to explore fossil association with extant colobines and functionally propose its dietary preferences based on multivariate morphometric analyses of mandibular morphology. The results indicate that this fossil species presents a mosaic association with extant langurs (<i>Presbytis, Trachypithecus</i>, and <i>Semnopithecus</i>) and odd-nosed monkeys (<i>Pygathrix, Nasalis</i>, and <i>Rhinopithecus</i>), with most similarities of size-related traits and size-adjusted shapes, and a notable difference from extant <i>Rhinopithecus</i>, due to the increased body size of the latter since the Pliocene. The allometric analysis showed that, like the fossils of the same species in other sites, its mandibular structure appears more adapted to crushing hard seed shells than chewing leaves. Moreover, our findings also imply that the Asian colobines significantly modified their dietary preferences over the last 6 million years following the ecological and environmental changes triggered by the accelerated uplift of the Qinghai-Tibet Plateaus and severe monsoons. Morphologically, the more developed condyle length and moment arms of the temporomandibular joint and medial pterygoid muscles appear to accommodate a more folivorous dietary selection, functionally related to the intake of rigid fibers in leaves that require frequent one or two-side mandibular chewing and grinding.</p></div>","PeriodicalId":7662,"journal":{"name":"American Journal of Primatology","volume":"87 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142845570","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":"Yawn Contagion and Modality-Matching in the Female-Bonded Society of Geladas (Theropithecus gelada)","authors":"Luca Pedruzzi,&nbsp;Paolo Oliveri,&nbsp;Martina Francesconi,&nbsp;Alban Lemasson,&nbsp;Elisabetta Palagi","doi":"10.1002/ajp.23709","DOIUrl":"10.1002/ajp.23709","url":null,"abstract":"<p>Behavioral contagion is widespread in primates, with yawn contagion (YC) being a well-known example. Often associated with ingroup dynamics and synchronization, the possible functions and evolutionary pathways of YC remain subjects of active debate. Among nonhuman animals, geladas (<i>Theropithecus gelada</i>) are the only species known to occasionally emit a distinct vocalization while yawning. Yet, the role of different sensory modalities in YC remains poorly understood. Due to their social and communicative complexity, geladas serve as an excellent model for investigating the effects of multimodality and social factors on behavioral contagion. Here we studied a large zoo-housed colony of geladas (103 subjects, 1422 yawns) and confirm the previous evidence for visual and auditory YC. Hearing, seeing, or hearing and seeing yawns significantly triggered contagious yawning at comparable levels. Additionally, we found no evidence of laterality influencing responses based on the side of detection. While the social bond, measured via grooming, between the trigger and receiver did not correlate with YC, a consistent sex effect emerged. Females responded more frequently to female than to male yawns and were more likely to match modality (i.e., vocalized vs. nonvocalized) and mirror morphology of other females' yawns. Effective female-female communication and affiliation are crucial for maintaining cohesion and fostering strong intra-unit relationships among geladas. Our results underscore the importance of different sensory components in the distribution of YC, particularly for species living in complex social systems. These findings raise further questions about the functional and emotional significance of yawning and potential inter-sexual differences, suggesting that the phenomenon is more complex than previously thought.</p>","PeriodicalId":7662,"journal":{"name":"American Journal of Primatology","volume":"87 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajp.23709","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142845507","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}