Distribution and geographic variation in the western woolly lemur (Avahi occidentalis) with description of a new species (A. unicolor)

The western woolly, lemur is distributed through central western, northwest ern and possibly, northern Madagascar and is traditionally viewed as a mono typic species (Avahi occidentalis) or as a subspecies of A. laniger. We pre sent new data on body weights of Avahi which, together with previously avai lable body, weights, provide additional evidence for recognizing eastern an d western woolly lemurs as two distinct species. We then reexamine the dist ributions of, and chromatic variation within and between, populations of we stern woolly, lemurs. A comparative study of wild subjects and museum skins reveals that several geographically discrete morphs exist in western Avahi , which is clearly, polytypic. Marked differences between populations in fu r coloration suggest that greater than or equal to3 distinct taxa should be recognized. The populations differ considerably in their habitat structure , In addition, field observations suggest clear differences in population d ensity between greater than or equal to2 of the populations, We describe an d name one new species.