Lesser Mouse Lemur
Lesser mouse lemurs are well adapted to a nocturnal lifestyle. Click image for larger version.
At one time in the fairly recent past, the genus Microcebus was thought to contain just two species with non overlapping ranges: the grey mouse lemur (M.murinus) found in the drier regions of the north, west and south and the brown mouse lemur (M.rufus) of the humid rainforest regions of the east. However, the world of primatology was rocked in 2000 with the announcement that no less than three new species of mouse lemurs had been discovered by an international team of primatologists working in the endangered forests of western Madagascar! That brought the total number of mouse lemur species to eight. Needless to say, in this day and age it is extremely rare that any new species of primate is discovered, much less three in one year!
Like the fat-tailed dwarf lemur, the lesser mouse lemur usually undergoes a season of torpor during Madagascar's dry season (April/May to September/October). At this time, female mouse lemurs become totally inactive and may remain dormant within their tree holes for several months (up to 176days). This conserves energy and reduces the threat of predation during the time of year when resources are scare. During this time, however, males might be much more active than females, perhaps establishing hierarchies for the upcoming breeding season. Prior to the dry season both sexes store large reserves of fat in their hind legs and tail (up to 35% of body weight) which helps get the animals through the period of resource scarcity.