HABITAT USE AND SUPPORT PREFERENCE OF 2 FREE-RANGING SALTATORY LEMURS(LEPILEMUR-EDWARDSI AND AVAHI-OCCIDENTALIS)

Lepilemur edwardsi and Avahi occidentalis are two species of nocturnal , folivorous 'vertical clingers and leapers' (VCL). They have a simila r body mass and share the same morphological adaptation for leaping. I n a field study under sympatric conditions at Ampijoroa, Madagascar, c omparison of support use with support availability using Jacobs' D pre ference values (Jacobs, 1974) showed that both species actively chose or avoided branches with certain qualities. However, while both specie s showed a preference for small oblique and horizontal branches, they selected them at different heights in the forest and with varying degr ees of preference and avoidance for the other available supports. Desp ite their traditional locomotor assignation, both species showed a sur prisingly strong preference for horizontal supports. These striking va riations in detail of support preference may aid the maintenance of sp ecies segregation and niche difference.