Study objects

Red Uakari

Scientific nameCacajao calvus ucayalii
Head-body length54-57 cm
Tail length15-16 cm
Body mass2800-3500 g
Distributionwestern Amazonia (south of Rio Amazonas between Rio Ucayali and Rio Yavarí)
Habitattropical rain forest of terra-firme type; seasonally in flooded forest and “aguajales” (swamps dominated by the palm Mauritia flexuosa)
Dietseeds, fruits, flowers, arthropods
Social organizationvery large groups of up to 150 individuals, probably organized into subgroups of 25-50 individuals consisting of one male-multiple female units
Mating systempolygyny? polygynandry?
Gestation length
and infant care
gestation length not known; infant carried by mother
Social behaviorallogrooming probably the most frequent affiliative behavior
Communicationmainly through vocalizations and mimics
Home-range sizenot exactly known; probably >10 km²
Interspecific relationsoften associated with squirrel monkeys (Saimiri sciureus)
Predatorsconfirmed: harpy eagles