Fat-tailed dwarf lemurs are about the same size as a small rat. They have soft and woolly fur. Their large, lustrous eyes are encircled by dark rings and they have a white stripe on their nose. Their color is brownish-red or gray with a white underside and they have white feet.
Fat-tailed dwarf lemurs live in western Madagascar and in the south as far the island’s southern tip. They occur in dry deciduous forests, moist evergreen forests and thorn scrub.
Fat-tailed dwarf lemurs are nocturnal. They live in a small group consisting of a male and female mated pair and their young from the last one or two mating seasons. Females usually occupy “home ranges” in the centre of a group’s range, while one male’s home range may overlap with those of a few females. Females, in general, appear to be dominant to males. These lemurs move in a squirrel-like quadrupedal fashion. They spend almost all their time up in trees. In the dry winter months they are dormant for as long as 6 months, nesting in tree holes, surviving on fat stored in their tails until the following wet season. While dormant, their body temperature varies with the ambient temperature. While sleeping and when dormant, they roll up into a tight ball. Fat-tailed dwarf lemurs tend to be quiet, with a few weak calls when making contact, with a louder cry in aggressive situations.
Fat-tailed dwarf lemurs exhibit monogamous (one male mating with one female exclusively) and polygynandrous (promiscuous) (both males and females having multiple mates) mating systems. Despite their monogamous structure, however, approximately 40% of the young have a different father. Fat-tailed dwarf lemurs start mating towards the end of November, the time they emerge from the winter hibernation. Gestation is for about 61 days, 1 to 4 young being born, although twins are very common. The young are born with their eyes open, well-developed and fully furred. The females nurse their babies and both parents keep them warm and protect them until they reach independence. Fat-tailed dwarf lemurs are mature at one year old, although females usually are not capable of being mothers until the age of 18 months.
Fat-tailed dwarf lemurs are mainly threatened by hunting and habitat loss, mainly as a result of slash-and-burn agriculture, bushfires and charcoal extraction. The predators of fat-tailed dwarf lemurs include fossas, hawks, owls and boas.
According to IUCN, the Fat-tailed dwarf lemur is abundant and widespread throughout its range but no overall population estimate is available. Currently this species is classified as Least Concern (LC), but its numbers today are decreasing.
Fat-tailed dwarf lemurs have a big part to play in the dispersal of seeds in the forests where they live, due to their diet. They are an important prey animal for medium-sized carnivores.