Poeppig’s woolly monkey lives in mixed-sex groups of between 10 and 45 individuals, and sometimes as many as 70 individuals. These groups travel up to two kilometres per day eating a diet of mainly fruit, but also leaves, flowers, gum, seeds, invertebrates, birds and small mammals (2) (5). They are very efficient seed dispersers (3). It is thought that they travel further when insect prey abundance is high (5). Home ranges of different groups overlap, but aggression between groups is rare and territoriality seems to be low (4). The males are dominant in the group hierarchy and both males’ and females’ positions in the hierarchy is influenced by age, character, familial and intra-group alliances (2) (3). Most active during the day, the monkeys sleep at night in the upper canopy. Communication between Poeppig’s woolly monkeys is visual, vocal and through smell. Males will rub their chests to indicate hostility; receptive females smack their lips and teeth-chatter, and submission to superiors is shown by lowering or shutting the eyes whilst making a sobbing sound and covering the mouth. This last action is also performed to reassure infants. Males and even occasionally females will use scent glands on their chests to mark territory and to assert dominance. The monkeys have around 14 known vocalisations including barks, screams, grunts, chuckles and loud descending trills. The alarm call ‘yoohk yoohk’ is given by the whole group in chorus when they feel threatened (2).
Female Poeppig’s woolly monkeys become sexually receptive at about four years old (3). They have a 21-day oestrus cycle, but young are only born about every two to three years. Pregnancy lasts a massive 223 days and single births occur at any time of year. After birth, the infant will cling to the female’s long chest fur, and from about two weeks will gradually spend more time riding on her back and is nursed for at least a year (3). Males are fully mature at eight years, and individuals can live for up to 25 years (2).