Extensive survey of the Endangered Coquerel's sifaka Propithecus coquereli

摘要

Coquerel's sifaka Propithecus coquereli has a large but highly fragmented distribution. Despite its Endangered (EN) IUCN conservation status, uncertainties persist regarding its actual distribution and its presence in forests that are thought to be part of its distribution range. We provide here the first extensive population surveys of Coquerel's sifaka across a large number of forest fragments neighboring 27 sites of its known and expected distribution range in northwestern Madagascar, including 12 previously visited sites. During our diurnal surveys carried out in the dry seasons from 2009 to 2011 we observed the species in 26 of the 27 visited sites. Combining our results with previously published data, we propose a refined update of the species' distribution range and identify areas to be surveyed. We also recorded the support tree species on which sifakas were observed, and note that, surprisingly, P. coquereli was frequently seen around villages and in areas dominated by introduced tree species. Although the species was present at almost all the visited sites of its highly fragmented distribution range, it remains unclear how viable the populations of a significant proportion of these sites actually are. Due to political instability and high rates of deforestation, large-scale conservation actions are urgently needed. We thus (1) discuss the outline of a possible metapopulation conservation action plan for P. coquereli and (2) identify priority sites and actions.