AbstractAn immature crab‐eating macaque (Macaca fascicularis), which was sitting on the river bank near the Orangutan Research and Conservation Project base camp in the Tanjung Puting Reserve, Kalimantan Tengah, Indonesia, was seized by a crocodile which rapidly emerged from the water and then resubmerged with the monkey in its jaws. As crocodile populations are in a decline throughout Borneo, crocodile predation on crab‐eating macaques was probably more frequent in the past. This predation may have influenced development of some behaviors with an antipredator function inM. fascicula