American Journal of Primatology最新文献

{"title":"Should Zoo Food Be Chopped for Ruffed Lemurs? It's Not so Black and White.","authors":"Jenna Mae Davison, Amy Hammond, Georgia Abernethy-Palmer, James Edward Brereton","doi":"10.1002/ajp.23695","DOIUrl":"https://doi.org/10.1002/ajp.23695","url":null,"abstract":"<p><p>Whole food diets in zoos have the potential to reduce microbial contamination and keeper preparation time, whilst also reducing food nutrient breakdown. Given these benefits, it is important to determine whether there is any value in chopping up food. Lemurs (Family Lemuridae) are common in zoos, with over 7500 individuals housed globally. Given their regular occurrence in collections, plus the high incidence of frugivory, lemurs are an excellent taxon to investigate food presentation effects on behavior. A study was undertaken at Beale Wildlife Park on a group of four black-and-white ruffed lemurs (Varecia variegata) to investigate food presentation and preference. Animal behavior was recorded using instantaneous focal sampling at 60 s intervals to record state behaviors and continuous focal sampling to record event behaviors in 1-h sessions. Food preference was done by recording the first three food items consumed by individual lemurs. Overall, food manipulation was significantly increased during whole food presentation allowing the lemurs to display species-specific behaviors. Feeding and foraging were highest during very chopped food condition and inactivity was lowest in very chopped food presentation. When looking at aggressive interactions, there was an increase in stealing and locomotion with food during whole food presentation, whereas biting and startle were lower. Proving high-value food items chopped and low-value food items whole could reduce aggression while reduce aggression seen over high-value food items. For food preference, sweet potato was consistently in the top three food items for all lemurs, with beetroot being the second most-picked food item. This suggests that these individuals have a strong preference for food items high in carbohydrates. Keeper preparation time was significantly reduced during whole food preparation. Further research assessing a wider range of zoo-housed species would be beneficial to assess the effects of food presentation on behavior.</p>","PeriodicalId":7662,"journal":{"name":"American Journal of Primatology","volume":" ","pages":"e23695"},"PeriodicalIF":2.0,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142581624","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":"Establishment and Validation of Fecal Secretory Immunoglobulin A Measurement for Intestinal Mucosal Health Assessment in Wild Lemurs","authors":"Leonie Pethig,&nbsp;Verena Behringer,&nbsp;Peter M. Kappeler,&nbsp;Claudia Fichtel,&nbsp;Michael Heistermann","doi":"10.1002/ajp.23694","DOIUrl":"10.1002/ajp.23694","url":null,"abstract":"<p>The measurement of biomarkers in blood and excreta can enable immune status assessment and provide prognostic information on individual health outcomes. In this respect, the fecal measurement of secretory immunoglobulin A (sIgA), the primary mammalian antibody for mucosal defense, has recently received increased interest in a few anthropoid primates, but a fecal sIgA assay for use in strepsirrhine primates has not yet been reported. Here, we develop and analytically validate a cost-effective in-house sandwich enzyme immunoassay for the extraction and measurement of sIgA in feces of redfronted lemurs (<i>Eulemur rufifrons</i>). We also tested a simple method for sIgA extraction that can be used under remote field conditions and undertook experiments to assess the robustness of sIgA concentrations to variation in processing and storage conditions of fecal extracts. Our analytical validation revealed that the assay recognizes immunoreactive sIgA in redfronted lemur feces, that sIgA can be measured accurately with no potential interference from the fecal matrix, and that assay reagents and performance are highly stable over time. The field-friendly extraction procedure produced sIgA results strongly correlated with those generated by a standard laboratory extraction method. Short-term storage at room temperature resulted in a slight decline in sIgA concentrations, whereas freezing extracts at −20°C kept sIgA levels stable for at least 3 months. Longer-term storage of &gt;5 months, however, led to a significant decline of sIgA concentrations. Multiple freeze-thaw cycles did not affect sIgA levels. This study, therefore, provides the basis for measuring fecal sIgA in lemurs and possibly other strepsirrhines. When samples are processed properly and stored frozen, and when sIgA analysis can be performed within 3 months upon sample collection, fecal sIgA measurements can become a valuable tool for monitoring aspects of immunity and health in both zoo-housed and wild-living lemurs.</p>","PeriodicalId":7662,"journal":{"name":"American Journal of Primatology","volume":"86 12","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajp.23694","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142567638","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":"Quantitative Analysis of the Brachialis and Triceps Brachii Insertion Sites on the Proximal Epiphysis of the Ulna in Modern Hominid Primates and Fossil Hominins","authors":"Neus Ciurana,&nbsp;Aroa Casado,&nbsp;Patrícia Rodríguez,&nbsp;Marcel García,&nbsp;Francisco Pastor,&nbsp;Josep M. Potau","doi":"10.1002/ajp.23690","DOIUrl":"10.1002/ajp.23690","url":null,"abstract":"<p>In several species of hominid primates with different types of locomotor behavior, we quantitatively studied the insertion sites of the brachialis and triceps brachii on the proximal epiphysis of the ulna. Our main objective was to evaluate the possibility of using the anatomical features of these insertion sites to infer the locomotor behavior of different species of fossil hominins. We measured the area of these muscle insertion sites using 3D bone meshes and obtained the value of each insertion site relative to the total size of the two insertion sites for each of the species studied. We also compared these relative values of the osteological samples with the relative mass of the brachialis and triceps brachii, which we obtained by dissecting these muscles in the same primate species. The relative values for the brachialis insertion were highest in orangutans, followed by bonobos, chimpanzees, gorillas, and humans. Fossil <i>Australopithecus</i> and <i>Paranthropus</i> had values similar to those of bonobos, while fossil <i>Homo</i> had values similar to those of <i>Homo sapiens</i>. The observed similarity in ulnar attachment sites between <i>Australopithecus</i> and <i>Paranthropus</i> and extant bonobos suggest that these hominins used arboreal locomotion to complement their bipedalism. These adaptations to arboreal locomotion were not observed in <i>Homo</i>.</p>","PeriodicalId":7662,"journal":{"name":"American Journal of Primatology","volume":"86 12","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajp.23690","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142567648","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":"Male Infanticide in the Northern Purple-Faced Langur (Semnopithecus vetulus Philbricki) in the Kaludiyapukuna Forest Reserve, Sri Lanka","authors":"Roberta Salmi,&nbsp;Amy Lu,&nbsp;Alexandra N. Hofner,&nbsp;Charith Madushan,&nbsp;Dilan Thisaru,&nbsp;Elizabeth K. Mallott,&nbsp;Rajnish Vandercone","doi":"10.1002/ajp.23693","DOIUrl":"10.1002/ajp.23693","url":null,"abstract":"<p>Infanticide, the killing of conspecific infants, has been observed in many species, including rodents, carnivores, and notably, primates. Although several adaptive and non-adaptive hypotheses have been proposed to explain this phenomenon, most cases to date appear consistent with the sexual selection hypothesis, particularly in primates. According to this hypothesis, males increase their reproductive success by eliminating unrelated unweaned infants, causing females to resume cycling earlier and allowing infanticidal males to mate and sire offspring sooner during their tenure. Here, we document the first confirmed cases of male infanticide in the Northern purple-faced langur, an endangered Sri Lankan colobine living in polygynous groups where outside males challenge resident males for reproductive access, resulting in a “takeover.” Following one male takeover, we documented infanticidal attacks on all three infants present, resulting in the wounding and killing of two and the disappearance of the third, all within the first 2 months of the male's tenure. We also describe: (1) changes in group composition following the male replacement, (2) the age and sex of the victims and perpetrator/s; (3) the effect of infant loss on female interbirth interval; (4) infant defense; and (5) mating access to the victim's mothers after the infanticide. We conclude that despite anthropogenic disturbance at some study sites, infanticide within this species appears to align with the sexual selection hypothesis. Nonetheless, genetic analyses on infants killed and born after the takeover are needed to provide conclusive evidence.</p>","PeriodicalId":7662,"journal":{"name":"American Journal of Primatology","volume":"86 12","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajp.23693","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142567644","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":"Feeding Platforms as an Effective Strategy to Prevent the Consumption of Refuse by Urban Populations of Capuchin Monkeys (Sapajus libidinosus)","authors":"Túlio C. Lousa,&nbsp;Murilo R. Camargo,&nbsp;Thalita S. Sacramento,&nbsp;Francisco D. C. Mendes","doi":"10.1002/ajp.23688","DOIUrl":"10.1002/ajp.23688","url":null,"abstract":"<div>\u0000 \u0000 <p>The availability of manmade foodstuffs in the environment may significantly alter the diets, behavior and health of wild animals and the ecosystems ecology. One of the principal problems faced by urban populations of capuchin monkeys is their contact with household refuse, which may provoke a number of impacts on the health of these animals. The present study tested the use of feeding platforms as a strategy to reduce the consumption of unhealthy foodstuffs by these animals and analyzed the influence of this measure on the activity patterns and social interactions of the study groups. For this, we verified the patterns of use of a feeding platform by a capuchin group in an urban park in Goiânia, central Brazil, and compared this study population with those of other parks where alternative feeding protocols are implemented, ranging from continuous provisioning to no intervention whatsoever. Behavioral data were collected using scan sampling. The data analysis was divided into two steps: (i) comparison of the different conditions found in the populations with varying types of feeding platform usage and (ii) comparison of the time budget among sites in the context of seasonal variation. The presence of feeding platforms effectively reduced the consumption of refuse in the study groups, although it did also cause an increase in agonism in the animals and altered their activity patterns, leading to a greater dependence on provisioned resources. The results of this study highlight the complex interaction between human activities and the local wildlife in the urban setting, and the need for more detailed studies, to develop more effective management strategies.</p></div>","PeriodicalId":7662,"journal":{"name":"American Journal of Primatology","volume":"86 12","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142556952","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":"Assessing Variance in Male Reproductive Skew Based on Long-Term Data in Free-Ranging Rhesus Macaques.","authors":"Anja Widdig, Lisa Engel, Angelina Ruiz-Lambides, Constance Dubuc, Brigitte M Weiß","doi":"10.1002/ajp.23687","DOIUrl":"10.1002/ajp.23687","url":null,"abstract":"<p><p>The unequal share in male reproduction (male reproductive skew) has been reported across primate species. To explain the distribution of male reproduction within groups various skew models have been applied to primates, however the \"dynamic tug-of-war\" model first accounted for the specifics of primate sociality. This model assumes that an increase in the number of competing males, a high degree of female cycle synchrony and their interaction will result in a lower degree of male reproductive skew. Here, we first tested the predictors of this model in rhesus macaques (Macaca mulatta) using long-term demographic and genetic data (up to 9 groups over 22 seasons) of the Cayo Santiago population (Puerto Rico). We also tested an extended version including group size and sex ratio and their interaction with female cycle synchrony. Finally, we investigated which male attributes determine the probability to become a top sire (highest paternity share per group and season). Confirming studies, male rhesus macaques exhibited low to medium degrees of reproductive skew based on the multinomial index, M. Unlike predicted, reproductive skew was higher in groups with more males. The extended analysis suggested that reproductive skew increased with group size in more male-biased groups, but decreased with group size in female-biased groups indicating that the numbers of male and female group members matter. We detected no effect of female cycle synchrony on the variance of reproductive skew. Finally, only maternal rank predicted the probability to become a top sire as long as males resided in their natal group. Together, our results did not support predictions by the dynamic skew model in rhesus macaques, but strengthen studies suggesting that other factors in addition to male-male competition predict male reproductive output in rhesus macaques. Future skew studies should consider female choice and alternative male mating strategies.</p>","PeriodicalId":7662,"journal":{"name":"American Journal of Primatology","volume":" ","pages":"e23687"},"PeriodicalIF":2.0,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142455979","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":"Heritability in the Rhesus Macaque (Macaca mulatta) Vertebral Column.","authors":"Catalina I Villamil, Jeziel J Negrón, Emily R Middleton","doi":"10.1002/ajp.23686","DOIUrl":"https://doi.org/10.1002/ajp.23686","url":null,"abstract":"<p><p>The vertebral column plays a central role in primate locomotion and positional behavior. Understanding its evolution, therefore, has the potential to clarify evolutionary processes that have occurred in the primate lineage as well as the specific behaviors of extinct primates. However, to understand primate vertebral anatomy, it is important to determine how much of this anatomy is heritable and how much develops as a response to environmental factors during life. We estimated heritability for vertebral counts as well as typical cervical, thoracic, and lumbar elements from 210 individuals from the pedigreed Cayo Santiago Macaca mulatta skeletal collection. We found moderate heritability of vertebral counts (h² = 0.216-0.326), but with strong heritability of the type of variation (e.g., a tendency to meristic or homeotic change) in the vertebral count (h² = 0.599), suggesting a possible explanation for high variability in vertebral numbers among the hominoids in particular. The moderate heritability of vertebral count also suggests that vertebral count is an unsuitable metric for estimating the ancestral state for some taxa. We found strong heritability in the morphology of cervical and upper lumbar zygapophyseal facets (h² = 0.548-0.550) and the thoracic spinous processes (h² = 0.609-0.761), including high heritability of the spinous process angle in the upper thoracic and upper lumbar elements (h² = 0.649-0.752). We suggest these are related to maintaining stability in the cervical and lumbar regions, and reducing motion in the thoracic region, respectively. We propose that spinous processes may contain greater phylogenetic information, whereas transverse processes may contain greater information of function 'in life'. We also found important size effects, suggesting that size is the most heritable component of overall form and largely responsible for intertrait differences. This suggests that it is inappropriate to indiscriminately remove size effects from morphological comparisons.</p>","PeriodicalId":7662,"journal":{"name":"American Journal of Primatology","volume":" ","pages":"e23686"},"PeriodicalIF":2.0,"publicationDate":"2024-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142455980","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":"Detection of Filariid Infections in Mexican Primate Populations Through qPCR","authors":"Brenda Solórzano-García,&nbsp;Norberto Colín García,&nbsp;Filippo Aureli,&nbsp;Gerardo Pérez-Ponce de León","doi":"10.1002/ajp.23685","DOIUrl":"10.1002/ajp.23685","url":null,"abstract":"<p>Filariae are parasitic nematodes of high veterinary and medical importance, responsible for some acute tropical diseases. They are transmitted through the bite of hematophagous vectors such as biting midges and blackflies. Filariae are among the most prevalent vector-borne parasitoses in Neotropical primates in which severe infections can cause inflammatory reactions and tissue damage. Given the location inside the host (peritoneal cavity, bloodstream, and lymphatics), the detection of filariid nematodes is challenging and is mostly postmortem; hence the scarcity of studies on the prevalence of filariae in wild primate populations. Here, we report the prevalence of filariid infections in free-ranging populations of Geoffroy's spider (<i>Ateles geoffroyi</i>) and black howler (<i>Alouatta pigra</i>) monkeys across southern Mexico, using a combination of noninvasive sampling and molecular diagnostic techniques. Fecal samples were screened for filariid DNA by qPCR protocols. A total of 88 samples were examined with an overall prevalence of 26%. Filariae were slightly more common in spider monkeys compared to howler monkeys. This study constitutes the first report of the prevalence of infection of filariid nematodes in populations of wild spider monkey across southern Mexico, and the first reporting of filariae in black howler monkeys, as part of a new era of primate parasitology and the diagnostics of parasite infections in light of the everyday more affordable molecular tools.</p>","PeriodicalId":7662,"journal":{"name":"American Journal of Primatology","volume":"86 12","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajp.23685","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142370765","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":"Howler Monkey Die-Off in Southern Mexico","authors":"Gilberto Pozo-Montuy,&nbsp;María del Socorro Aguilar-Cucurachi,&nbsp;Filippo Aureli,&nbsp;Margarita Briseño-Jaramillo,&nbsp;Domingo Canales-Espinosa,&nbsp;Anaid Cárdenas-Navarrete,&nbsp;Liliana Cortés-Ortiz,&nbsp;Alejandro Coyohua-Fuentes,&nbsp;Fabiola Carolina Espinosa-Gómez,&nbsp;Montserrat Franquesa-Soler,&nbsp;Candelaria García-Duran,&nbsp;Yuliana García-Ojeda,&nbsp;Mónica Rosario González-Acosta,&nbsp;Javier Hermida-Lagunes,&nbsp;Laura Teresa Hernández-Salazar,&nbsp;Cristina Jasso-del-Toro,&nbsp;José Alberto Lizama-Hernández,&nbsp;Ileana Zorhaya Martínez-Ramos,&nbsp;Edgar J. Montejo-Zetina,&nbsp;Guadalupe Núñez-Martínez,&nbsp;Paulina Y. Nuñez-Ramírez,&nbsp;Pedro Shautamai Pareja-Badillo,&nbsp;Braulio Pinacho-Guendulain,&nbsp;Gabriel Ramos-Fernández,&nbsp;Ariadna Rangel-Negrín,&nbsp;Alix Fernanda Rivera-Sánchez,&nbsp;Elizabeth Sánchez-Domínguez,&nbsp;Juan Carlos Serio-Silva,&nbsp;Sandra E. Smith-Aguilar,&nbsp;Brenda Solórzano-García,&nbsp;Denise Spaan,&nbsp;Sarie Van Belle,&nbsp;Pedro A. D. Dias","doi":"10.1002/ajp.23684","DOIUrl":"10.1002/ajp.23684","url":null,"abstract":"<div>\u0000 \u0000 <p>In May and June 2024, a die-off of Mexican mantled howler monkeys (<i>Alouatta palliata mexicana</i>) occurred in southern Mexico. This commentary documents the event, attributing it to extreme heatwaves, drought, wildfires, and habitat impoverishment. Despite their reported resilience to habitat disturbances, mantled howler monkey mortality rate in some areas reached 31%. Key evidence points to heatstroke as the primary cause of death, exacerbated by limited hydration and reduced dietary diversity in disturbed habitats. Immediate responses included community-led rescues (e.g., hydrating the monkeys), coordination of rescue activities by nongovernmental organizations (NGOs) (e.g., managing donations), involvement of scientists (e.g., monitoring of primate populations), and assistance from government officials (e.g., providing legal support for animal management). This event underscores the urgency of developing action plans to prevent and attend future crises. Among other actions, we highlight (i) establishing primate care infrastructure with medical and rehabilitation centers; (ii) developing protocols and training programs to ensure rapid crisis response; (iii) fostering collaboration among government, NGOs, and academic institutions for effective crisis management; and (iv) developing targeted research on climate change impacts, predictive models, and long-term health monitoring. We emphasize the critical need for coordinated conservation efforts to protect wild primates and maintain natural ecosystem resilience in the face of escalating climate challenges.</p></div>","PeriodicalId":7662,"journal":{"name":"American Journal of Primatology","volume":"86 12","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142279108","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":"Body Mass Gain in Wild Brown Capuchins (Sapajus apella) in Relation to Fruit Production and Social Dominance","authors":"Nelson F. Galvis,&nbsp;Daniela Rodríguez,&nbsp;Pablo R. Stevenson","doi":"10.1002/ajp.23683","DOIUrl":"10.1002/ajp.23683","url":null,"abstract":"<div>\u0000 \u0000 <p>In ecological contexts natural selection might favor individuals with a larger body mass to monopolize resources; however, there is wide variation in body mass within populations and potential factors. In this study, we evaluated whether fruit production limits body mass in one group of <i>Sapajus apella</i>, its effects on behavior, and whether there is a relationship between social status and body mass. We recorded activity patterns using focal follows (20 min), body mass (using a modified Ohaus scale), and community wide fruit production estimates (from 60 fruit traps). Body mass remained relatively stable during periods of food scarcity, but in periods of abundance most individuals gained weight, as indicated by their relative growth rates (RGR). Subordinate subadults showed the highest RGR, as expected by their age. In periods of high fruit production activities as traveling, grooming, and playing were more frequent than during fruit scarcity, suggesting energy maximization and potential energetic constraints. We found differences in behavior within the group, as the alpha male was observed feeding more frequently (and for longer periods of time), was more aggressive (e.g., feeding trees), and received more grooming than other individuals. In addition, the alpha male was 60% heavier than the group's average body mass. Our study supports the hypothesis that body weight gain is related to fruit abundance and that body size is associated with social dominance; however, large individuals (both males and females) seem to incur in high metabolic or reproductive costs, as they do not gain much weight as smaller individuals.</p></div>","PeriodicalId":7662,"journal":{"name":"American Journal of Primatology","volume":"86 12","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142258824","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}