Perseguição de bugio infante (Alouatta fusca) por macacos-prego (Cebus apella): predação ou brincadeira?

Robust capuchin (Sapajus apella) and howler monkeys (Alouatta sp.) are sympatric species in several areas of Brazil, but no records of social interactions between these species were reported to this date (2004). This work will describe an interaction event between a group of capuchin monkeys and two howler monkeys.
The animals inhabit the Tietê Ecological Park, in a preservation area of 180,000 m². The group of capuchin monkeys is composed of 17 individuals and there is no record
how many howlers live in the area; during the observed interaction, only one infant and one adult were observed. The event was recorded on VHS video, focusing on the howler monkey infant.
In the episode there were chases and bites to the howler infant, folowed by its fall, caused by the capuchins. The episode lasted approximately 21 minutes, with the participation of 10 individuals from the capuchin group (3 adults, 2 subadults, 3 juveniles and 2 infants). A subadult female was the individual that most interacted with the howler monkey (14 times), followed by a juvenile male, an adult male and a female subadult (8 times). During the interaction the capuchins  pulled and bit the howler infant, which emitted vocalizations. At some point during the event, subadult females and a subadult male capuchins exhibited characteristic threat behaviors, such as bristling and showing teeth.
There are records of predation by capuchin monkeys on small mammals. This event resembled an attempt to capture, in view of the threat displays, the high number of individuals involved and the great amount of time spent, however, the predation did not occur. In the rare past encounters between the two species in this place, interactions never scaled beyond threats by the capuchin monkeys to adults howlers. Another hypothesis would be the curiosity provoked by the novelty of the howler infant, given the great excitement demonstrated by the capuchins and the participation of juveniles and infants, which would allow to also characterize the episode as a play event. Similar interspecific interactions have been observed in this park between capuchins and coatis, ranging from captures and kill of newborns from nests, neutral encounters, grooming, and reciprocal play.