Capuchin monkeys hunt prey when fruits and vegetables become scarce, potentially mirroring the habits of human ancestors, according to a study published August 26, 2026 in the open access journal PLOS One by Susana Carvalho (Gorongosa National Park, Mozambique), Noemi Spagnoletti (Sapienza University of Rome, Italy) and colleagues.
Humans are the only living primates who regularly hunt animals larger than themselves, a lifestyle thought to have emerged alongside large brains and complex social structures. This predatory habit might have begun with the eating of smaller prey, as seen in other primates such as chimps and capuchins. To determine what factors lead primates to hunt, Carvalho, Spagnoletti and colleagues investigated the hunting habits of capuchin monkeys.
The team observed two groups of bearded capuchins in Fazenda Boa Vista, Brazil. Between 2006-2010, they observed more than 5,000 hours of the capuchins' behavior and documented 446 instances of them eating small animals, mostly lizards (43%) and rodents (28%). These included the first recorded cases of these monkeys eating opossum, iguana, and bird nestlings. Compared with female monkeys, males hunted prey more often and went after more dangerous prey like snakes. Diets also varied based on environmental conditions, with an increase in hunting when plant foods were less accessible. The monkeys also tended to prefer the brains and guts of prey, seemingly prioritizing fat-dense tissues.
These results suggest that capuchins turn to vertebrate prey during times of plant food scarcity, a pattern that has been suggested for ancestral humans during climate fluctuations, but that the monkeys' hunting habits also vary based on sex and on which nutrients are lacking in their diet. The authors suggest that future studies may confirm these patterns in capuchins and other primates, and that fossil research might seek evidence of similar patterns in the prey of early humans to determine whether our modern relatives are an adequate model for the evolutionary origins of human predatory habits.
Susana Carvalho, Director of Science at Gorongosa National Park and one of the lead authors of the study, adds: "This study highlights the critical need of long-term observational field work to reliably understand the behavior of long-lived and highly flexible primate species."
"When we look at 45 months of data, we see small vertebrates like lizards, rodents and snakes as a key source of food when less fruit is available - and a preferential target for prey brains and viscera. Hunting small prey could have been an important source of nutrition for human ancestors, during periods of food scarcity, providing a steppingstone to the exploitation of larger prey - the fossil record now needs re-analyzing to look at evidence of small vertebrate predation."
Author interview: https://plos.io/4hCq173
In your coverage, please use this URL to provide access to the freely available article in PLOS One: https://plos.io/3TWAsZl
Citation: Carvalho S, Spagnoletti N, d'Oliveira Coelho J, Beardmore-Herd M, Mendonça-Furtado O, Verderane M, et al. (2026) Small vertebrate consumption by capuchin monkeys (Sapajus libidinosus): Insights into the human predatory pattern. PLoS One 21(8): e0355204. https://doi.org/10.1371/journal.pone.0355204
Author countries: Portugal, Italy, UK, Brazil, Chile.
Funding: This work was financially supported by a Scholarship for postgraduate study abroad (Law 398/89, Rector's Decree of 25/01/2006) given to Noemi Spagnoletti by the University La Sapienza of Rome; EU FP6 NEST Programme ANALOGY (NS: 029088, Elisabetta Visalberghi PI for the ISTC-CNR Unit); FAPESP PhD scholarships (MPV: 06/51578-9; OMF: 08/52293-3) and FAPESP to Patrícia Izar PI (06/51577-2 and 08/55684-3), CNPq research grant # 307731/2096-5 to Patrícia Izar PI, CAPES (NS: 017/2012) to Noemi Spagnoletti PI, CNR Short-term Mobility Program to Elisabetta Visalberghi, and Funding from Ethoikos srl to Elisabetta Visalberghi PI. Open Access to this article is financed by FCT – Fundação para a Ciência e a Tecnologia, within the scope of the project ICArEHB UID/04211/2025 (DOI: https://doi.org/10.54499/UID/04211/2025 ). There was no additional external funding received for this study. None of the funders had a role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
