Comparison of reproductive characteristics and changes in body weight between captive populations of rufous and gray mouse lemurs

The nocturnal Malagasy mouse lemurs are among the smallest primates worldwi de. Several sibling species are known. Of these, the rufous and the gray mo use lemur differ with respect to morphology, genetics, and communication. T hey might also differ in seasonal reproduction and body weight changes. We investigated and compared reproductive activities and changes in monthly bo dy weight in males and females of successfully bleeding colonies of both sp ecies under the same photoperiodic conditions. Females of both species show ed estrous cycles only during the long-day period. Rufous mouse lemur femal es seemed to have a shorter gestation than their sibling species (57 vs. 62 days). The number of estrous cycles (2.25 vs. 2.5/season) and their length s (59 vs. 52 days) were similar Litter size (2) seemed to be similar Latenc y of estrous occurrence after photoperiodic stimulation was longer in Micro cebus rufus than in its sibling species (71.6 and 42.3 days). The same was true for the onset of the growth of the testes. The rate of growth and size of the testes were similar, and precede the estrous onset in both species. The reproductive activity was shorter in both sexes of the rufous than of the gray mouse lemurs. In both species, body weight showed similar seasonal changes. Males lost more weight during the breeding season than females di d. In rufous mouse lemurs, body weight was similar in both sexes during the nonbreeding season. In gray mouse lemurs, sexes differed throughout the ye ar.