Occurrence of the critically endangered Coquerel’s Sifaka (Propithecus coquereli) across a fragmented landscape in northwestern Madagascar
Habitiat loss and fragmentation affect species occurence and distribution in rapidly changing ecosystems. These issues are especially relevant on the island of Madagascar where modern deforestation has been widespread and is ongoing. We investigated the occurence of the critically endangered Coquerel´s Sifaka (Propethicus coquereli) in an anthropogenically modified landscape: the Mariarano region of Northwestern Madagascar. We surveyed four large forest sites from 500 to 5,000 ha and 16 forest fragments ranging from 1.5 to 19.2 ha in size. We recorded various attributes of the visited sites such as area, distance to nearest large forest, and anthropogenic disturbance. We encountered sifakas in 10 out of 16 fragments and in all large forest sites, with the majority of encounters occuring in habitat edge zones. Furthermore, we encountered 19 sifakas in the matrix such as in villages and fields. We found tha neither human disturbance, area, nor distance to a large forest predict the presence of sifakas in the Mariarano region. Our results suggest that Coquerel´s sifakas are able to persist in highly degraded and small forest fragments under certain conditions, but further research is needed in their long-term viability in anthropogenically modified landscapes.