A great initiative of the Udzungwa Mountains National Park staff has been working with a troupe of rare endemic Sanje mangabeys, helping them to become habituated to people. Tracking them daily and observing their behavior, the Park staff usually know where the troupe is and can find them given a day or two notice.
It is possible for visitors to arrange to take a hike “off-piste” into the forest just above Hondo Hondo and walk via radio direction straight to the troupe of Mangabeys. This gives you the opportunity to observe them from very close quarters, undisturbed. It’s an excellent way to get close to this endemic species/genus without disruption to their natural habits. The Mangeabeys are very used to humans, and can come very close, allowing for the best photo opportunities and the chance to see this rare primate in great detail.