Habitat use and conservation status of black-and-white colobus (colob us angolensis) and blue monkeys (Cercopithecus mitis) in Amani Nature Reserve, Tanzania.

Habitat use and conservation status of the two primate species black and white colobus monkeys (Colobus angolensis) and blue monkeys (Cercopithecus mitis) at Amani Nature Reserve (ANR), Tanzania, was studied from June 2003 to May 2004. Methods used included animal counts, follows and opportunistic observations as well as animal signs, hunting signs and interviews with villagers and officials around ANR. The estimated population size for blue monkeys and black and white colobus monkeys at ANR was 1965 and 413, with a density of 23.51 individuals/km2 and 4.94 individuals/km2^ respectively. Black and white colobus monkeys preferred heights above 21m, while blue monkeys preferred heights lower than 21m. Habitat preference in relation to number of visits and time spent was highest in slightly disturbed forest followed by primary forest for both species; in contrast time spent per area was highest in slightly disturbed forest followed by moderately disturbed forest for black and white colobus monkeys. Both species showed higher preference on forest edges and tall open canopy habitats, and they had highest feeding records and dietary diversity indices in the slightly disturbed forest. Furthermore, both species were more abundant, and exhibited larger group sizes of healthier composition in the slightly disturbed forest patches. Human-monkey interaction was found to increase with proximity to human settlements. This study indicated that these monkeys could flourish in slightly disturbed forest habitats but not in higher levels of disturbance; therefore, more habitat disturbance in ANR is a great threat to the survival of these monkey species. Further research, protection of forest patches and participation of local communities around ANR in conservation planning are strongly recommended.