Zanzibar Red Colobus - Communication

Communication

The red colobus species have a smaller larynx compared to other members of the Colobinae subfamily. The male's call is more of an alto or soprano in contrast to the low bass of a male's in black-and-white colobus species. The Zanzibar red colobus is non-territorial in nature and as so does not typically make loud, territorial threat calls. Zanzibar red colobus distress and warning calls are the "bark", "chist", or "wheet". One of the loudest calls from the monkey is heard when he expresses his dominance over the group and when checking the sexual status of his females.

The call heard most often by people in or near Jozani Forest is the 'alerting signal'. This is an attention-getting call that is derived from the progression call. Chirps and grunts are made when there are changes in the surrounding environment such as changes in weather or animal movement in proximity to the group. With most arboreal animals, there are two different alerting calls, one for when a predator is on land, and another when there is an aerial predator. However, because of the lack of larger birds of prey in Zanzibar, such calls are not often witnessed. The young, on the other hand, because of their smaller size and vulnerability, do at times make such calls when they see shadows.

Because the Zanzibar red colobus is extremely social, it has a specific call for when it is alone for a certain amount of time upon which it feels vulnerable or threatened. The young are typically the ones to make such a call that sounds like a loud scream, but adults are occasionally likely (when deemed necessary) to make some variation of the call as well.