Habitat Utilization of Three Sympatric Cheirogaleid Lemur Species in a Littoral Rain Forest of Southeastern Madagascar

I compared the habitat utilization in 3 sympatric species of Cheirogaleidae (Microcebus murinus 81 g], Cheirogaleus medius 183 g] and Cheirogaleus major 362 g]) in a littoral rain forest in southeastern Madagascar during 3 rainy seasons. Females of promiscuous Microcebus murinus had small home ranges and the males had large overlapping home ranges. Home ranges of family groups of monogamous Cheirogaleus medius and C. major overlapped extensively. Home ranges of all 3 species overlapped completely in the study area but home range sizes differed among species and correlate positively with body masses. Male Microcebus murinus slept in open vegetation (79%) and alone (71%), whereas female M. murinus and family group members of Cheirogaleus spp. preferred communal sleeping in tree holes. There are significant interspecific differences in the choice of sleeping sites: smaller lemurs chose smaller trees and used more sleeping sites than larger lemurs did. Species also differed significantly in the vertical dimension of forest utilization: Cheirogaleus major used the upper part of the trees, C. medius used the middle parts, and Microcebus murinus used the understory during nocturnal activities. The 3 species differed mainly in vertical habitat utilization and showed vertical stratification.