White-eared Titi - Behaviour

Behaviour

The white-eared titi is cryptic, diurnal and known to live in small family groups. It is a monogamous species that is thought to mate for life and lives in groups that usually consist of two to seven members; an adult pair and up to five young. Multi-male groups have also been recorded. Offspring are carried by the male, and are always with them, except when feeding. Between the ages of two to four years, offspring will disperse from the natal group, with females leaving earlier than the males.

There is a strong bond between the adult mating pair, they stay close and carry out activities together. Either member of the pair may follow the other and leadership changes through the day. Evidence of the strength of the pair bond is shown by grooming, huddling together with their tails twined, nuzzling, and gentle grasping. Titi monkeys are highly territorial and when confronted with another family group, both will respond with threatening behaviour, males showing increased agitation towards intruding males. When not close together, the pair show a significant amount of distress and agitation.

Titi monkeys are well known for their vocal communication, and have a complex repertoire of calls. The calls can be divided into two categories: high-pitched quiet calls and low-pitched loud calls. Vocalisations are often combined and repeated to form sequences that are used to indicate distress, conflict, play, bonding, disturbance, and to strengthen territory. The high-pitched quiet calls are mostly used when the monkeys are disturbed, but may also be used before or after group calling, while foraging, or to find other members of the group. The loud low-pitched calls are mostly used in long distance group calling. Their function is to ensure adequate spacing between the home ranges of different family groups. These vocalisations are known as duets, and generally involve the male and female. If a neighbouring group is within earshot of these calls they will respond with their own duetting.

The white-eared titi is arboreal, spending most of its time in the lower strata of the forest. It may enter the main canopy when travelling longer distances and may also cross small areas of open ground, though the latter is rare. During normal movement through its environment it is quadrupedal and mostly walks, clambers and leaps, but it can also bound and climb. It leaps small distances, no more than a few body lengths, between trees where vegetation is not thick enough to support its primary forms of locomotion. When travelling on the ground it is said to use a "bounding movement" whereby it leaps more than 1 metre (3.3 ft) off the ground. The titi monkey prefers branches which are less than 5 centimetres (2.0 in) in diameter and its tail never touches the support it is on.