Capuchin Monkeys in Panama Caught Kidnapping Howler Monkey Babies

An unusual and tragic phenomenon has been unfolding on Jicarón Island, part of Panama’s Coiba National Park, where scientists have documented white-faced capuchin monkeys abducting baby howler monkeys and inadvertently causing their deaths.

According to researchers from the Smithsonian Tropical Research Institute, the incident was first noticed when motion-activated cameras, initially installed to study tool use among capuchins, captured surprising footage in early 2022. One juvenile male capuchin, later nicknamed “Joker” because of a scar on his mouth, was seen carrying a howler monkey infant on his back. Over the following months, Joker was recorded abducting multiple howler babies, sometimes keeping them for several days.

Reported by the study team, this strange conduct was not isolated. Other juvenile and subadult male capuchins began copying the behavior, leading to at least eleven known abductions over a 15-month period. The footage showed the young males often handling the infants gently, but lacking the ability to feed or properly care for them. In most cases, the howler babies died, either from starvation or stress, with some even being carried after death.

Eye witness accounts from field researchers describe distressed howler parents calling out nearby as their infants were taken. Scientists believe the behavior spread like a social fad among the capuchins, similar to how certain learned habits can move through primate groups.

The cause remains uncertain. According to primatologists, the capuchins on Jicarón live in an environment with no predators, abundant food, and little competition, which may leave them with more time to experiment with unusual activities. Others suggest the kidnappings could be a misplaced caregiving instinct or simply juvenile curiosity gone awry.

This is the first recorded case of one primate species repeatedly abducting and killing the young of another without consuming them or gaining a clear survival advantage. Researchers warn that if the trend continues, it could threaten the already vulnerable howler monkey population on the island.

The findings, reported by the scientists in Current Biology, highlight the complex and sometimes puzzling cultural behaviors that can emerge among intelligent animals  behaviors that, in this case, have devastating consequences for another species.