Current researchers and their research projects

Immigrant male TJ forms a coalition with juvenile male Kahlo
The following summarizes current research by members of the Lomas Barbudal Monkey Project, which is currently based at UCLA. These researchers are not employees or volunteers of the WCF. The WCF aids the UCLA-based project in finding volunteers and promoting the work of the project to the public.

Behavioral flexibility across the lifespan: In 2019, we will focus our research efforts on understanding how behavioral repertoires change across the lifespan. In this study, we will extend our developmental study (which started in 2001), using longitudinal data to investigate how individuals change with age with regard to their propensities to innovate and learn socially from others, across a wide span of behavioral domains. This research will help us understand both how learning strategies shift with experience and changing life circumstances, and how the age structure of populations affects social transmission dynamics. This study is funded by the L.S.B. Leakey Foundation.

Social norms:
 We are currently investigating dyad- and group-specific behaviors related to individuals' understanding of the rules of social life.  This research has two primary components: (1) investigation of the quirky dyadic rituals that capuchins invent for testing the quality of their social bonds, and (2) investigation of the question of whether capuchins exhibit social norms. We define "social norms" as moralized, group-specific, socially learned, shared understandings of the rules by which social life should be conducted, which are maintained via moral emotions that inspire impartial third parties to punish violators of these rules. This work is funded by the Templeton World Charity Foundation's Diverse Intelligences Initiative.

Coalitions and alliance formation: Susan Perry and her UCLA graduate students Tlaoli Fuentes and Kotrina Kajokaite are studying capuchin politics, coalitionary psychology and life histories. Coalitions are such an important part of daily life for capuchins, and alliances are necessary for achieving high reproductive success. We are interested in studying how the monkeys communicate their requests for assistance, and how they decide with whom to side in these conflicts. We are very grateful to the L.S.B. Leakey Foundation and the National Geographic Society for funding this project.

Inbreeding avoidance: Irene Godoy (a recent UCLA PhD, currently teaching at Radboud University in the Netherlands) conducted her Ph.D. research on the mechanisms by which fathers avoid inbreeding with their reproductive aged daughters and granddaughters, even when they co-reside with them as alpha males. Her research was funded by L.S.B. Leakey Foundation, NSF, and the Wenner-Gren Foundation. She continues to publish papers in this area.  Her recent papers include:
Godoy, I., Vigilant, L. & Perry, S. 2016. Inbreeding risk, avoidance and costs in a group-living primate, Cebus capucinus. Behavioral Ecology and Sociobiology 70:1601–1611, DOI: 10.1007/s00265-016-2168-1
Godoy, I., Vigilant, L. & Perry, S. 2016. Cues to kinship and close relatedness during infancy in white-faced capuchin monkeys, Cebus capucinusAnimal Behaviour 116:139-151.

Social learning and food processing: Brendan Barrett (who received his PhD from UC-Davis in 2017) conducted his field research on the role of social learning in the acquisition of skill in opening panama fruits.  Brendan and Susan are also collaborating in analysis of a long-term data set on the role of social learning in the processing of Sloanea fruits. Brendan’s PhD research was funded by American Society of Primatologists, an NSF graduate fellowship, and the ARCS Foundation Northern California Chapter. The first paper to emerge from this project is:
Barrett, B.J., McElreath, R., & Perry, S.E. 2017. Payoff-biased social learning underlies the diffusion of novel extractive foraging traditions in a wild primate. Proceedings of the Royal Society B 284: 20170358.

Male migration and female counter-strategies: The funding for this 4-year project (funded by NSF grant 0848360, the Leakey Foundation, and the National Geographic Society) ended in August, 2013, though data collection and analysis are still underway and form a part of several graduate student thesis projects. Two papers stemming from this project include:
Perry, S., Godoy, I., Lammers, W., & Lin, A. 2017. Impact of personality traits and early life experience on timing of emigration and rise to alpha male status for wild male white-faced capuchin monkeys (Cebus capucinus) at Lomas Barbudal Biological Reserve, Costa Rica. Behaviour 154(2):195-226
Schaebs, F., Perry, S., Cohen, D., Mundry, R. & Deschner, T. 2017. Social and demographic correlates of male androgen levels in wild white-faced capuchin       monkeys (Cebus capucinus). Amer. J. Primatol. DOI: 10.1002/ajp.22653