About

Jacinta C. Beehner is a Professor of Psychology and Anthropology at the University of Michigan, serving as Associate Chair of Graduate Studies and directing several research projects including the University of Michigan Gelada Research Project, the Capuchins at Taboga Project, and the Beehner Endocrine Laboratory. Her overarching research theme focuses on identifying situations where male and female reproduction come into conflict with one another, particularly in mammalian species where females typically invest more in offspring due to gestation and lactation costs. Her work aims to understand how this reproductive conflict manifests in physiology and behavior, especially through female counterstrategies to male coercive tactics such as infanticide, male-mediated pregnancy termination, and deceptive fertility. She employs an evolutionary perspective, utilizing comparative and mechanistic approaches, including assessing fecal hormone profiles across different primate species living in their natural environments in Africa and the Americas, such as baboons, geladas, and capuchins. Her research seeks to incorporate these strategies into evolutionary models to predict social systems across mammals, with a focus on understanding reproductive success and social dynamics in highly social animals with reproductive skew.

Research topics

• Biology
• Immunology
• Evolutionary biology
• Zoology
• Philosophy
• Genetics
• Bioinformatics
• Epistemology
• Cognitive science
• Ecology
• Psychology

Selected publications

• Longitudinal variation in urinary chemicals associated with dominance rank changes in wild male capuchin monkeys

  Zenodo (CERN European Organization for Nuclear Research) · 2026-04-24

  otherOpen access

  Establishing and maintaining dominance hierarchies can come at significant costs to the individuals involved. Across social mammals, cues and signals conveying competitive ability, including olfactory ones, have evolved to mitigate these costs. In a longitudinal study, we tested whether shifts in male dominance rank predict changes in urinary chemical profiles in wild white-faced capuchins (Cebus imitator), primates that exhibit rank-based male bimorphism and behaviors consistent with urine-based chemical signaling. We further investigated whether chemical changes associate with hormonal patterns and/or putative olfactory signaling behaviors. We analyzed urinary chemical profiles collected from 22 males before, during, and after their groups experienced an alpha male replacement (AMR) event, comparing patterns across dominance rank categories (ascending alphas, descending alphas, and stable subordinates). Male urinary chemical profiles changed significantly over the course of an AMR, and we detected a number of urinary compounds whose presence and/or abundance varied and may be associated broadly with AMR events. We also measured individual fecal androgen levels, and examined urine washing behavior to assess their association with changes in urinary chemicals. We did not find any clear relationships between urinary chemical composition and fecal androgen production or urinary signaling behavior, suggesting a potential temporal disconnect in these traits as males change in rank during an AMR event. These results lay the groundwork for future research using targeted, integrative approaches to identify chemicals that may mediate social relationships, including dominance rank status, advancing the methods and study of chemical communication in social mammals. Keywords. Olfactory communication, Chemosignaling, Alpha male replacement, Male dominance rank status, Male bimorphism, Primates.

  PublisherDOI

• Longitudinal variation in urinary chemicals associated with dominance rank changes in wild male capuchin monkeys

  Zenodo (CERN European Organization for Nuclear Research) · 2026-04-24

  otherOpen access

  Establishing and maintaining dominance hierarchies can come at significant costs to the individuals involved. Across social mammals, cues and signals conveying competitive ability, including olfactory ones, have evolved to mitigate these costs. In a longitudinal study, we tested whether shifts in male dominance rank predict changes in urinary chemical profiles in wild white-faced capuchins (Cebus imitator), primates that exhibit rank-based male bimorphism and behaviors consistent with urine-based chemical signaling. We further investigated whether chemical changes associate with hormonal patterns and/or putative olfactory signaling behaviors. We analyzed urinary chemical profiles collected from 22 males before, during, and after their groups experienced an alpha male replacement (AMR) event, comparing patterns across dominance rank categories (ascending alphas, descending alphas, and stable subordinates). Male urinary chemical profiles changed significantly over the course of an AMR, and we detected a number of urinary compounds whose presence and/or abundance varied and may be associated broadly with AMR events. We also measured individual fecal androgen levels, and examined urine washing behavior to assess their association with changes in urinary chemicals. We did not find any clear relationships between urinary chemical composition and fecal androgen production or urinary signaling behavior, suggesting a potential temporal disconnect in these traits as males change in rank during an AMR event. These results lay the groundwork for future research using targeted, integrative approaches to identify chemicals that may mediate social relationships, including dominance rank status, advancing the methods and study of chemical communication in social mammals. Keywords. Olfactory communication, Chemosignaling, Alpha male replacement, Male dominance rank status, Male bimorphism, Primates.

  PublisherDOI

• Intergroup Encounters Among Wild White-Faced Capuchins (Cebus imitator) at a Densely Populated Field Site: Insights into Frequency, Intensity, and Participation

  International Journal of Primatology · 2026-04-06

  articleOpen access

  Abstract 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 ( Cebus imitator ) 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.

  PublisherOA PDFDOI

• Female reproductive ageing persists despite high infanticide risk in chacma baboons and geladas

  Royal Society Open Science · 2025-01-01 · 2 citations

  articleOpen access

  Across mammals, fertility and offspring survival are often lowest at the beginning and end of females’ reproductive careers. However, extrinsic drivers of reproductive success—including infanticide by males—could stochastically obscure these expected age-related trends. Here, we modelled reproductive ageing trajectories in two cercopithecine primates that experience high rates of male infanticide: the chacma baboon ( Papio ursinus ) and the gelada ( Theropithecus gelada ). We found that middle-aged mothers generally achieved the shortest interbirth intervals in chacma baboons. By contrast, old gelada females often showed shorter interbirth intervals than their younger group-mates with one exception: the oldest females typically failed to produce additional offspring before their deaths. Infant survival peaked in middle-aged mothers in chacma baboons but in young mothers in geladas. While infant mortality linked with maternal death increased as mothers aged in both species, infanticide risk did not predictably shift with maternal age. Thus, infanticide patterns cannot explain the surprising young mother advantage observed in geladas. Instead, we argue that this could be a product of their graminivorous diets, which might remove some energetic constraints on early reproduction. In sum, our data suggest that reproductive ageing is widespread but may be differentially shaped by ecological pressures.

  PublisherOA PDFDOI

• Disparate social structures are underpinned by distinct social rules across a primate radiation

  Proceedings of the National Academy of Sciences · 2025-07-31

  preprintOpen access

  ABSTRACT Over six decades of research on wild baboons and their close relatives (collectively, the African papionins) have uncovered substantial variation in their behavior and social systems. While most papionins form discrete social groups (single-level societies), a few others form small social units that are nested within larger supergroups (multi-level societies). These two systems are generally thought to be qualitatively distinct, but data from wild populations increasingly suggest that there may be areas of overlap. To quantify this potential gradient in social structure, a more systematic, comparative analysis is needed. Here, we constructed a database of behavioral and demographic records spanning 135 group-years, 28 social groups, 13 long-term field studies, and 11 species to quantify variation in grooming network structure, and identify the individual and dyadic properties (e.g., kinship and social status effects) that underlie this variation. Consistent with accumulating observations in the field, the single-level species could be divided into two categories: cohesive and cliquish . Cohesive single-level networks were dense, kin-biased, and moderately rank-structured, while cliquish single-level networks were more differentiated, slightly more kin-biased, and strongly rank-structured. As expected, multi-level networks were very modular and shaped by females’ ties to specific dominant males but varied in their kin biases. Taken together, these data suggest that (i) kin and rank biases are widespread but vary in their strength; (ii) male-centered subgroups are exclusive to multi-level systems; and (iii) increases in network modularity can emerge in response to heightened nepotism and male-centered clustering. SIGNIFICANCE STATEMENT What forces explain variation in primate societies? While kinship and dominance shape the social lives of many of our close relatives, it is unclear how their effects differ across species. Using a new database comprising decades of field research, we found that baboons and their close relatives fell into three general patterns: one in which groups were cohesive, kin-biased, and moderately rank-biased, another in which groups were more cliquish and nepotistic, and a third in which groups were divided into clusters centered on dominant males. Distinct primate societies may thus reflect differences in the strength of females’ nepotistic biases and the degree of males’ social influence.

  PublisherOA PDFDOI

• Author response for "Conditional benefits of social integration in wild female geladas"

  2025-04-22

  peer-review
  PublisherDOI

• Field experimentation enhances translation for behavioral neuroscience

  Neuropsychopharmacology · 2025-07-25

  article1st author
  PublisherDOI

• Early-life infection dynamics and genomic diversity of adenoviruses in a wild primate (Theropithecus gelada)

  Microbial Genomics · 2025-12-08

  articleOpen access

  In humans, adenoviruses (AdVs) are frequently associated with respiratory illnesses, posing risks to children with developing immune systems and immunocompromised individuals. Outbreaks and epidemics are generally centred in close-contact settings, such as childcare facilities, and transmission occurs through faecal–oral and airborne pathways. AdVs have coevolved across the primate lineage, but very little is known about whether the early-life dynamics in non-human primates mirror those in humans. Here, we leverage longitudinal data collected on a population of geladas ( Theropithecus gelada ) in the Simien Mountains National Park, Ethiopia, to evaluate AdV dynamics across the gelada lifespan. We identified ten coding-complete AdV genomes representing seven unique simian adenovirus (SAdV) types, four of which are adequately different from the known ones to establish new species. We assessed behavioural and seasonal drivers of SAdV presence and richness across repeated faecal samples from known individuals. Contrary to our expectation that the highest risk would occur after the initiation of play behaviour in infancy (~6 months of age), when peer-to-peer transmission risk is expected to increase, SAdV likelihood was highest in infants under 6 months of age. Risk and richness declined over the lifespan, with very few adults infected, and higher minimum temperatures were weakly but significantly negatively associated with richness. Our results suggest that, unlike in humans, SAdV exposure occurs prior to the initiation of close-contact play behaviours and likely results from the close spatial proximity of conspecifics throughout the dependent period. Like AdVs in humans, SAdVs in geladas maintain low levels in adulthood, with early infections potentially conferring life-long immunity.

  PublisherDOI

• Evidence for deceptive fertility in a wild primate

  Current Biology · 2025-11-19 · 1 citations

  articleSenior author
  PublisherDOI

• Stress responsiveness in a wild primate predicts survival across an extreme El Niño drought

  Science Advances · 2025-01-22 · 5 citations

  articleOpen accessSenior authorCorresponding

  We know more about the costs of chronic stress than the benefits of the acute stress response-an adaptive response that buffers organisms from life-threatening challenges. As yet, no primate study has empirically identified how the stress response adaptively affects evolutionary fitness. Here, we take advantage of a natural experiment-an El Niño drought-that produced unprecedented mortality for wild white-faced capuchins. Using a reaction norm approach, we provide evidence from primates that a more robust stress response to a challenge, measured using fecal glucocorticoids, predicts a greater likelihood of survival. We show that individuals with greater stress responsiveness to previous droughts later had higher survival across a severe El Niño drought. Evolutionary models need empirical data on how stress responsivity varies in adaptive ways. While we cannot buffer subjects from catastrophic events, we can use them to understand which aspects of the stress response help animals to "weather the storm."

  PublisherDOI

Recent grants

• Doctoral Dissertation Research: Examining causes and consequences of variation in male reproductive success in wild primates

  NSF · $28k · 2020–2023

• Doctoral Dissertation Research: Examining the evolutionary significance of chest patch coloration in a wild primate population

  NSF · $25k · 2021–2023

• Doctoral Dissertation Improvement: The Reproductive Trajectories of Geladas (Theropithecus gelada)

  NSF · $20k · 2010–2012

• LTREB: Social dynamics and fitness in a complex primate society

  NSF · $450k · 2013–2018

• Doctoral Dissertation Research: A test of the vocal grooming hypothesis in the gelada

  NSF · $25k · 2013–2015

Frequent coauthors

• Thore J. Bergman

  University of Michigan–Ann Arbor

  104 shared

• Noah Snyder‐Mackler

  Arizona State University

  43 shared

• Amy Lu

  George Washington University

  43 shared

• Robert M. Seyfarth

  University of Pennsylvania

  23 shared

• Tracy M. Montgomery

  Michigan State University

  22 shared

• Dorothy L. Cheney

  21 shared

• Susan C. Alberts

  Duke University

  17 shared

• Julia Fischer

  University of Göttingen

  17 shared

Education

• Ph.D., Anthropology

  Washington University in Saint Louis

  2003

• M.A., Anthropology

  Washington University

  1998

• B.S.

  Boston College

  1994