Faculty Portrait

Contact Information

Name: Clara J. Scarry

Title: Assistant Professor

Office Location: MND 4030

Email: Clara.Scarry@csus.edu

Office Phone: 916.278.7337

Mailing Address: Department of Anthropology, California State University, Sacramento, 6000 J Street, Sacramento, CA 95819-6106

Office Hours: Academic Year 2020/2021: Mondays, Wednesdays and Fridays from 9-10 AM via Zoom

Research Interests

Research Expertise

  • Intergroup aggression and male cooperation
  • Collective decision-making and group coordination
  • Large-scale field experiments
  • Primate ranging behavior and site fidelity

I am a broadly trained biological anthropologist with a research focus on primate behavioral ecology, particularly among Neotropical primates. Much of my work has examined the connections between intergroup aggression, intragroup relationships and individual decision-making and behavioral strategies, as a means to understand the evolution of cooperation.

Because it is collective by nature, cooperation during intergroup aggression is difficult to maintain. I have focused on untangling individual strategies underpinning successful collective action in this context among others primates and identifying the correlates of these behaviors for the individual (e.g., mating access, social bonds, and hormonal response) and emergent group-level properties (e.g., semi-exclusive home ranges). I have established a long-term research project studying intergroup aggression among tufted capuchin monkeys in the Parque Nacional Iguazú, Argentina, where I am a directing PI of the “Proyecto Caí”, and also collaborate on projects with spider monkeys and woolly monkeys in Yasuní Biosphere Reserve, Ecuador.


Current Research Projects

Note: I am recruiting graduate students to work at either of these two sites on individual research projects.

My primary research site at Iguazú National Park, Argentina

Inequity aversion, individual decision making, and the emergence of collective behavior

For cooperation to be maintained reciprocal altruism, individuals must be able to assess the equitability of their own payoffs relative to their partners. In captivity, capuchin monkeys have demonstrated both the cognitive capacity to assess outcome inequities and to use prior experience to inform decisions about whether or not to cooperate with social partners. These dyadic studies, however, have been unable to address how a predisposition for inequity aversion affects the consensus decisions that groups must make for successful coordination and cooperation to occur. To examine how these behaviors translate to individual decisions within more natural social and ecological contexts, my collaborators and I are using a series of large-scale field experiments to assess 1) whether perceptions of inequity are conditional upon properties of the social relationship (e.g., dominance, social affiliation) and 2) whether the expression of inequity aversion affects group coordination. 

Comparative ecology of capuchins in natural and anthropogenic landscapes

I am working as part of an international collaborative effort to use tufted capuchin monkeys as a model to study how generalist primate species respond to highly fragmented landscapes. Outside of native forest reserves, Argentine capuchin monkeys are found in anthropogenic landscapes that are dominated by exotic pine plantations and small fragments of native forest. Because capuchin populations are declining – the species is listed as vulnerable to extinction within Argentina – whereas the industrial timber plantations are expanding, developing sustainable strategies to promote coexistence of commercial stakeholders and capuchins is critical for the long-term survival of the species. Our initial work focuses on 1) a comparison of movement decisions and space use requirements by capuchins living in undisturbed versus anthropogenic habitats and 2) identifying the ecological drivers of bark-stripping behavior by capuchins, which causes commercial damage and is setting up an incipient human-capuchin conflict in the region.



Salmi R, Presotto A, Scarry CJ, Hawmann P, Doran-Sheehy DM. 2020. Spatial memory in western gorillas (Gorilla gorilla): An analysis of distance, linearity and speed of travel routes. Animal Cognition 23: 545–557. doi: 10.1007/s10071-020-01358-3

Scarry CJ. 2020. Against all odds: cooperative resource defense among tufted capuchin monkeys. American Journal of Primatology 82: e23094. doi: 10.1002/ajp.23094

Brividoro MV, Kowalewski MM, Scarry CJ, Oklander LI. 2019. Selection and use of sleeping sites by black-and-gold howler monkeys (Alouatta caraya) in northern Argentina. International Journal of Primatology 40: 374-392. doi: 10.1007/s10764-019-00094-x

Scarry CJ. 2017. Collective male resource defense during intergroup encounters among tufted capuchin monkeys. Animal Behaviour 123: 169-178. doi: 10.1016/j.anbehav.2016.10.015

Scarry CJ. 2016. Intergroup encounters. In: The International Encyclopedia of Primatology. (Fuentes A, ed). John Wiley & Sons, Inc. doi: 10.1002/9781119179313.wbprim0198 (invited)

Veilleux CC, Scarry CJ, Di Fiore AF, Bolnick DA, Kirk EC, Lewis RJ. 2016. Group benefit associated with polymorphic trichromacy in a Malagasy primate (Propithecus verreauxi). Scientific Reports 6: 38418. doi: 10.1038/srep38418

Van Belle S, Scarry CJ. 2015. Numerical assessment during collective action in Neotropical primates. Philosophical Transactions of the Royal Society, B. (invited) doi: 10.1098/rstb.2015.0007

Wheeler BC, Scarry CJ, Koenig A. 2013. Rates of agonism and dominance style among female primates: associated factors and implications for socioecological models. Behavioral Ecology 24:1369-1380. doi: 10.1093/beheco/art076

Koenig A, Scarry CJ, Wheeler BC, Borries C. 2013. Variation in grouping patterns, mating systems, and social structure: what socioecological models attempt to explain. Philosophical Transactions of the Royal Society, B. (invited) doi: 10.1098/rstb.2012.0348

Scarry CJ. 2013. Between-group contest competition among tufted capuchin monkeys (Sapajus nigritus) and the role of male resource defence. Animal Behaviour 85: 931-939.

Scarry CJ, Tujague MP. 2012. Consequences of lethal intragroup aggression and alpha male replacement on intergroup relations in tufted capuchin monkeys (Cebus apella nigritus). American Journal of Primatology 74:804-810.

Williams RC, Nash LT, Scarry CJ, Videan EN, Fritz J. 2010. Factors affecting wounding aggression in a colony of captive chimpanzees (Pan troglodytes). Zoo Biology 29: 351-364.



Ph.D., Biological Anthropology, Stony Brook University
M.A., Biological Anthropology, Stony Brook Unviersity
B.A., Anthropology, Arizona State University
B.S., Biology and Society, Arizona State University


Courses that I teach:

ANTH 1: Introduction to Biological Anthropology
ANTH 133: Life of Primates
ANTH 154: Primate Behavior
ANTH 155: Fundamentals of Biological Anthropology
ANTH 179: Observing Primate Behavior
ANTH 202: Biological Anthropology Seminar



An adult male capuchin monkey with an infant
Tufted capuchin monkeys at rest
A subadult female capuchin monkey
A juvenile capuchin monkey