The Mouse lemur ( Microcebus sp. ), family of Cheirogalidae,
Is the smallest primates in the world. This species body length is less than 5 inches long ( Head and body length : 12 cm, Tail length : 13 cm ). Discrete and not so easy to find in the nature, this little mammal of Madagascar ranging from around 30 grams to 75 grams. Mouse lemur is strictly nocturnal and in the whole day, it sleeps in a hollow shaft or in a tree cavity.
Olfaction is particularly important to lemurs. Olfaction can communicate information about age, sex, reproductive status, as well as demarcate the boundaries of a territory. Small, nocturnal lemurs mark their territories with urine.
Mouse lemur can live 15 years and they are all « mouse-like » in appearance. At present the genus Microcebus contains 16 species ; the most common are the Grey Mouse Lemur ( found in the drier regions of the north, west and south of Madagascar ) and the Brown Mouse Lemur ( found in humid rainforest regions of the east of Madagascar ).
The Grey Mouse lemurs ( Microcebus murinus )
The Grey mouse lemur is the largest mouse lemur. Found in dry deciduous lowland forest, in spiny forest and in some degraded forests including plantations between Onilahy River ( south west of Madagascar ) and Ankarafantsika-Ampijoroa forestry station ( north west of Madagascar ). And also an apparently isolated and disjointed population near Mandrare River and in Andohahela National Park ( deep south of Madagascar ).
The Grey mouse lemur is nocturnal and omnivorous ( mainly fruit, flowers, nectar - so act as pollinators -, insects and secretions produced by insects, gum from Euphorbia and Terminalia trees, small treefrogs, geckos and chameleons ) ; largely solitary when foraging and occupies small home ranges of 1 - 2 hectares. They can be extremely abundant and females become totally inactive in dry season ( April to October ) to conserve energy and reduce predation. Gestation is about 60 days and birth occurs in tree hole or leaf nest.
The Grey mouse lemur predators include raptors and owls, carnivores like ringtailed mongoose, narrow-striped mongoose and fosa, also large snakes. Easy to see at Ankarafantsika-Ampijoroa forestry station, at Kirindy forest ( west of Madagascar ) and at Berenty private reserve ( south of Madagascar ).
The Brown Mouse lemur ( Microcebus rufus )
The Brown mouse lemur is a very small active lemur with long tail. Found in lowland and montane rainforests and in secondary vegetation and some adjacent plantations ( between Tolagnaro = Fort Dauphin ( deep south of Madagascar ) to Tsaratanana Massif ( north of Madagascar )). You can observe it too in marshes and reed beds around Lac Alaotra.
The Brown mouse lemur is too nocturnal and omnivorous ( mainly fruit - over 40 species eaten -, flowers, nectar - so act as pollinators -, insects and arthropods ) ; both solitary and gregarious. Both sexes lay down fat reserves in tail and other areas of body during wet season and become inactive during part of winter. Males prepare for breeding in mid-August. Mating occurs between September and November, and births from November to January.
The Brown mouse lemur predators include raptors, other birds e.g. Hook-billed Vanga and owls, carnivores like ringtailed mongoose and fosa, also large snakes. Easy to see at Nosy Mangabe ( north east of Madagascar ) and at Ranomafana National Park ( south east of Madagascar ).
Social systems of Mouse lemurs ( Madagascar )
Nocturnal lemurs are mostly solitary but social, foraging alone at night but often nesting in groups during the day. In many nocturnal species the females, along with their young, will share nests with other females and possibly one male, whose larger home range happens to overlap one or more female nesting groups.
Activity patterns of Mouse lemurs ( Madagascar )
In order to conserve energy and water in their highly seasonal environment, Mouse lemurs exhibit seasonal behavioral cycles of dormancy. They are ( with Dwarf lemurs ) the only primates known to do so. Prior to the dry winter season, when food and water are scarce, they will accumulate fat reserves in their hind legs and the base of their tail. During the dry season, they can exhibit daily and prolonged torpor.
Mouse lemurs have been observed experiencing torpor that lasts for several consecutive days, ( but Dwarf lemurs are known to hibernate for six to eight months every year ( May through September and more ) ) particularly on the west coast of Madagascar.