White-eared Titi - Ecology

Ecology

There is relatively little known about the ecology of the white-eared titi or even titi monkeys in general, and few studies have focused on the white-eared titi. It is diurnal, commencing activity around sunrise and continuing until sunset. Food availability may influence activity times; if there is an abundance of food in the warmer months when plants are fruiting titi monkeys may start earlier, or if there is a lack of food, titi monkeys may remain at the feeding tree into the evening. The titi monkey usually rests during the middle of the day and has two main feeding periods, in the morning and in the afternoon. It has an increased period of feeding towards the end of the day. In total, the titi monkey is active for an average of 11.5 hours, 2.7 hours of which is spent feeding. Titi monkeys sleep on branches at least 15 metres (49 ft) above the ground. In the same manner as resting during the day, titi monkeys huddle together and twine tails to sleep.

Though there is little published research on the diet of the white-eared titi, titi monkeys in general are omnivores that eat fruit, leaves, insects, and seeds. They mostly eat leaves, especially protein-rich young leaves and leaf buds, so a significant period of the day is spent resting to digest the cellulose. They consume more than 100 different species of plants and fruit. Titi monkeys will also eat small insects (ants, moths, butterflies, and their cocoons), spiders, and can catch flying prey if it comes close to them. During the dry season there is an increased feeding time on leaves, and during lactation it is thought insect consumption increases to augment the protein content of the diet.

The titi monkey may travel between 425 and 1,152 m (1,394 and 3,780 ft) during the day, and can maintain a home range of 0.005 to 0.14 km2 (0.0019 to 0.054 sq mi). During the dry season there is less fruit available and therefore less need to travel large distances, so the day range may only be a third of the usual distance. Its home range is often shared with other primate species including marmosets, squirrel monkeys, capuchins, owl monkeys, howler monkeys, and spider monkeys. It is sometimes chased from feeding sites by larger species, and will generally try to avoid other primates.