Fat-Tailed Dwarf Lemur
The species of dwarf lemur found at the DLC, Cheirogaleus medius, is native to the dry deciduous forests common in western and southern Madagascar. These small lemurs can live in primary forests, established secondary forests as well as the gallery forest of the southern spiny desert. Typically solitary foragers, the dwarf lemurs have a diverse diet consisting mostly of fruit and flower nectar. While they are thought to be less carnivorous than mouse lemurs, they too eat insects and small vertebrates. Dwarf lemurs may be responsible for pollinating some species of baobab trees. In addition, they play an important role in the ecology of the tropical forest by aiding in the dispersal of small seeds. As a part of their normal scent marking routine, dwarf lemurs often smear feces onto branches as they walk along well-traveled arboreal pathways through the forest, thereby providing a perfect microclimate for the germination of parasitic plants common in the forest.
Feeding
The western dwarf lemur, Cheirogaleus medius, can increase its body weight by 75g (about 40%) at a time. It effectively gorges during times of food abundance, to prepare for Madagascar’s dry season when its diet of fruits and flowers is scarce. In the winter months, most dwarf lemurs enter a state of torpor. While mouse lemurs also enter into a winter torpor, only dwarf lemurs experience it for such a long time each year. Neither captive nor wild mouse and dwarf lemurs actually hibernate, but they do experience a slow down in their metabolic rates and show a marked decrease in activity and appetite which may last for up to six months. During this period of increased torpor, these lemurs live off of fat stored in their tails.
Since the climate is more variable and extreme in the western part of Madagascar, the western dwarf lemur shows a greater degree of torpor than the eastern dwarf lemur. Torpor begins as early as March, when the dwarf lemurs retreat to shelters such as those offered by hollow tree trunks. They sometimes do not emerge until the beginning of the wet season in November. Up to five animals may be found huddled together during this period.
To prevent obesity in our captive dwarf and mouse lemurs during their torpor period, the DLC has established a “winter diet” and a “summer diet.” The winter diet is initiated in early to mid-September, with a gradual decrease in rations fed to the animals. Starting in mid-March the diet is then increased gradually, reaching the full summer diet amount during the breeding season. Without the reduced rations of the winter months, the dwarf lemurs would continue to consume any and all food provided, which, coupled with a greatly reduced rate of metabolism, could result in extreme obesity!
Fact Sheet
Order: Primates; Suborder: Prosimii
Family: Cheirogaleidae; Genus: Cheirogaleus
Species: medius
Related Species
There are two species of dwarf lemurs: the greater dwarf lemur (Cheirogaleus major) and the fat-tailed dwarf lemur (Cheirogaleus medius).
Key Facts
Adult Size : 0.4 - 0.6 pounds
Social life : Solitary forager, strictly nocturnal, sleeps in groups of up to 5 individuals
Habitat : western dry deciduous forests and southern deciduous thicket
Diet : fruit, flowers (nectar) and occasional insects and small vertebrates
Lifespan : 15 - 20 years in the wild
Sexual maturity : 2 years
Mating : Extremely seasonal, November
Gestation : 61 - 64 days, infants are born in January
Number of young : one - four infants per litter, one litter each year
DLC Naming theme : Birds (Woodcock, Waxwing, Hummingbird, etc.)
Malagasy names : Matavirambo, Kely Be-ohy, Tsidy, Tsidihyv
Interesting Facts
- The fat-tailed dwarf lemur is one of the smallest lemurs.
- Fat-tailed dwarf lemurs survive long periods of food shortage by storing fat in their tails!
Reproduction
The strong seasonality of breeding found in mouse and dwarf lemurs depends upon a variable "photoperiod," or day length.
Dwarf and Mouse lemurs breed at the DLC from mid-April through July. Gestation is 58-62 days. Both species commonly have litters of two or more offspring.
All captive dwarf lemurs are provided with a wide variety of nestboxes, ranging from PVC tubes of varying sizes, to wooden boxes, to suspended enrichment boxes, all suitable for sleeping and raising young. Mothers give birth in the nestboxes and generally will keep their infants hidden inside these shelters. If they need to move their offspring, they do so by carrying them in their mouths. Mouse and dwarf lemur offspring of up to three weeks of age are transported by the mother in this fashion, but by the time the infants are two months old they are behaving much like adults and are capable of independent locomotion.
On average, mouse and dwarf lemurs reach sexual maturity at one year of age, although females generally are not capable of giving birth until they are 18 months of age. In the wild, juvenile dwarf lemurs tend to enter their first period of dormancy later than adults, perhaps providing the youngsters with a period of reduced feeding competition in which to put on additional pre-torpor weight.
Social Behavior
Dwarf lemurs forage in solitude at night. During the day they congregate, in packs of up to five to a tree hole, while they sleep. The composition of these sleeping groups changes seasonally, and often animals do choose to sleep alone.
Sleeping sites generally consist of hollow trees, whose cavities have been cushioned with leaves. Otherwise, they are spherical nests made of dead leaves concealed in heavy undergrowth.
During the mating season, mouse lemur males sleep with females more often than during other times of the year. For the rest of the year females sleep with their dependent offspring in groups of up to 15.
Females generally occupy "home ranges" in central areas of a group's range, while a single male may overlap his home range with those of several females. Female prosimians, in general, are considered dominant to males, but this may not be universal.
Habitat/Conservation
The east and west coasts of Madagascar provide very two different forest habitats for four similar subspecies of dwarf and mouse lemurs. Cheirogaleus medius (the fat-tailed dwarf lemur) and Microcebus murinus (the gray mouse lemur) occupy the west, while Microcebus rufus (brown mouse lemur) and Cheirogaleus major (greater dwarf lemur) live in the east. These subspecies' smallness, nocturnality and ability to live in secondary forests have protected both dwarf and mouse lemurs from threats of extinction. However, as with all lemurs of Madagascar, habitat destruction and hunting increasingly threaten their survival.
In the eastern rainforest of Madagascar, conditions do not fluctuate as much as in the west, so eastern lemurs display less of a need for seasonal torpor. Eastern dwarf lemurs have a shorter period of dormancy than their western cousins: For example, Microcebus rufus, with a body mass ten times smaller than Cheirogaleus major, feeds on fruits and insects through the winter, and doesn’t go into torpor at all.
Mouse and dwarf lemurs breed well in captivity, but since populations are not endangered in the wild, captive population numbers are low and steadily shrinking.