This phenomenon marks the first documented case of one species abducting the young of another without clear motivation, with researchers observing a total of 11 howler infants being carried over a 15-month period.

If this infant-stealing behavior continues, it could threaten the already vulnerable howler monkey subspecies on the island.

Co-author Margaret Crofoot expressed hope that some howler babies might have escaped back to their mothers, although there is no evidence to support this.

The study highlights how non-human animals can evolve cultural traditions without clear functions, drawing parallels to human cultural phenomena.

Published on May 19, 2025, in the journal Current Biology, the study contributes to the understanding of primate behavior and social interactions.

The research, which began in 2017, utilized over 85 camera traps to monitor the behavior of Panamanian white-faced capuchins, initially focusing on their tool use.

Zoë Goldsborough, a behavioral ecologist at the Max Planck Institute, described the findings as shocking and unprecedented in the animal kingdom.

The behavior appears to be unique to a specific group of capuchins, highlighting significant behavioral diversity within the species.

Researchers suspect this behavior may represent a 'cultural fad' among capuchins, potentially influenced by their unique ecosystem conditions.

While the exact motivation remains unclear, some researchers propose it could be a form of play or curiosity, similar to using a toy.

This trend poses a significant concern for the endangered howler monkey population, as noted by researcher Susan Perry.

The unusual behavior of capuchin monkeys kidnapping baby howler monkeys was first detected in 2022 on Jicarón Island, Panama, using motion-activated cameras.