Around 1,100 of the animals live in the highland Ndundulu Forest Reserve, a forest adjacent to Udzungwa Mountains National Park, and in a disjunct population 250 miles away on Mount Rungwe and in Kitulo National Park, which is adjacent to it. The forest at Rungwe is highly degraded, and fragmentation of the remaining forest threatens to split that population into three smaller populations. The Ndundulu forest is in better shape, but the population there is smaller.