Two tayras (Eira barbara) were observed attacking an infant red-handed howler (Alouatta belzebul) on an island in eastern Brazilian Amazonia, as a nearby adult male watched passively. In a separate incident, four tayras were seen attacking a subadult female on the ground. Tayras were also observed in the vicinity of the two howler study groups on a number of occasions over a 9-month period. During this same period, the two groups lost a third of their members, including infants and subadults, and the remains of six animals were found at the study site. While tayras were the only predators seen attacking the howlers, it remains unclear to what extent they were responsible for apparently high mortality rates in this high-density, isolated howler population.