Geographic Range
Fat-tailed dwarf lemurs are found in the dry forests of western Madagascar and south
to the southern tip of Madagascar, where their range extends into moist evergreen
forest habitats.
Habitat
Fat-tailed dwarf lemurs inhabit dry deciduous forests and thorn scrub forests in western
Madagascar. Their range extends to southeastern Madagascar, where they inhabit moist
evergreen forests. They are seen on thick and medium-sized branches that are usually
low down. Fat-tailed dwarf lemurs make their nests in holes in trees, where they lie
dormant throughout the dry season.
- Habitat Regions
- tropical
- terrestrial
- Terrestrial Biomes
- forest
- scrub forest
Physical Description
Fat-tailed dwarf lemurs are small animals, about the size of a small rat. Head and
body length is 20 to 23 cm and tail length is 20 to 27 cm. Body weight varies between
120 and 270 grams, being heaviest just prior to entering seasonal torpor. Their fur
is soft and woolly. They have large, lustrous eyes which are surrounded by dark rings.
They are a brownish-red or grey color, and their underside is completely white. Along
with the dark eye rings, fat-tailed dwarf lemurs have a white nasal stripe and white
feet.
- Other Physical Features
- endothermic
- heterothermic
- bilateral symmetry
- Sexual Dimorphism
- sexes alike
Reproduction
Females have an estrous cycle which lasts about 20 days. During this time males compete
fiercely for the estrous females. Social groups consist of a mated female and male
and offspring from previous breeding efforts. Despite this apparently monogamous structure,
approximately 40% of young are fathered by a different male.
- Mating System
- monogamous
- polygynandrous (promiscuous)
Fat-tailed dwarf lemurs begin mating near the end of November, when they emerge from
their winter torpor. The gestation period is approximately 61 days and 1 to 4 young
are born, although twins are most common. Fat-tailed dwarf lemurs become sexually
mature in their second year of life.
- Key Reproductive Features
- iteroparous
- seasonal breeding
- gonochoric/gonochoristic/dioecious (sexes separate)
- sexual
- viviparous
Fat-tailed dwarf lemur females care for their young by nursing them and protecting
them until they are independent. Young are born well-developed, fully furred and with
their eyes open. Both females and male participate in caring for the young.
- Parental Investment
- altricial
-
pre-fertilization
- provisioning
-
protecting
- female
-
pre-hatching/birth
-
provisioning
- female
-
protecting
- female
-
provisioning
-
pre-weaning/fledging
-
provisioning
- female
-
protecting
- male
- female
-
provisioning
-
pre-independence
-
protecting
- male
- female
-
protecting
- post-independence association with parents
Lifespan/Longevity
Fat-tailed dwarf lemurs are reported to have lived up to 20 years in captivity.
Behavior
Fat-tailed dwarf lemurs are nocturnal primates. They live in small groups of a mated
male and female and their offspring from the previous one or two breeding seasons.
They move in a quadrupedal, squirrel-like fashion. Fat-tailed dwarf lemurs spend virtually
all their time in trees. During the winter dry months they become dormant for up to
6 months, nesting in holes in trees. During this time they use stored fat in their
tails to survive until the next wet season. Their body temperatures while dormant
vary with ambient temperature. During sleep and times of dormancy they are rolled
up in a tight ball. No territorial behaviors or marking have been observed. Population
densities range from 40 to 400 per square kilometer.
Home Range
Communication and Perception
Fat-tailed dwarf lemurs are relatively quiet animals. They do have a few weak calls
for contact and a louder cry in agonistic situations. They use fecal scent marks to
mark territories.
Food Habits
Fat-tailed dwarf lemurs are predominantly frugivores, but they also feed on flowers,
seeds, nectar and insects. They take small vertebrates occasionally. During the wet
season fat-tailed dwarf lemurs store fat in their tails in preparation for their dry
season aestivation. Just before aestivation they begin to incorporate higher quantities
of fruit in their diet.
- Animal Foods
- reptiles
- insects
- Plant Foods
- seeds, grains, and nuts
- fruit
- nectar
- flowers
- sap or other plant fluids
Predation
Predators of fat-tailed dwarf lemurs include fossas, Madagascar harrier-hawks, Madagascar buzzards, barn owls, Madagascan long-eared owls, and native boas. Fat-tailed dwarf lemurs are nocturnal and cryptically colored, which helps them to avoid some predation.
- Anti-predator Adaptations
- cryptic
Ecosystem Roles
Fat-tailed dwarf lemurs may play a role in seed dispersal in the forests they inhabit. They are also important prey for medium sized carnivores.
Economic Importance for Humans: Positive
Since these animals are confined to only the island of Madagascar their economic importance to humans is extremely little, if their is any at all.
Economic Importance for Humans: Negative
There are no known negative impacts of Cheirogaleus medius on humans.
Conservation Status
Fat-tailed dwarf lemurs are currently listed as lower risk/least concern by the IUCN.
They are considered endangered by the U.S. Endangered Species Act and on Appendix
I of CITES by virtue of being in the family
Cheirogaleidae
. They are fairly widespread and abundant currently and populations are protected
in 4 national parks.
Additional Links
Contributors
Tanya Dewey (author), Animal Diversity Web.
Kevin F. Older (author), University of Michigan-Ann Arbor.
- Ethiopian
-
living in sub-Saharan Africa (south of 30 degrees north) and Madagascar.
- native range
-
the area in which the animal is naturally found, the region in which it is endemic.
- tropical
-
the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.
- terrestrial
-
Living on the ground.
- forest
-
forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.
- scrub forest
-
scrub forests develop in areas that experience dry seasons.
- endothermic
-
animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.
- heterothermic
-
having a body temperature that fluctuates with that of the immediate environment; having no mechanism or a poorly developed mechanism for regulating internal body temperature.
- bilateral symmetry
-
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
- monogamous
-
Having one mate at a time.
- polygynandrous
-
the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.
- iteroparous
-
offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).
- seasonal breeding
-
breeding is confined to a particular season
- sexual
-
reproduction that includes combining the genetic contribution of two individuals, a male and a female
- viviparous
-
reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.
- altricial
-
young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.
- arboreal
-
Referring to an animal that lives in trees; tree-climbing.
- nocturnal
-
active during the night
- motile
-
having the capacity to move from one place to another.
- sedentary
-
remains in the same area
- solitary
-
lives alone
- acoustic
-
uses sound to communicate
- chemical
-
uses smells or other chemicals to communicate
- visual
-
uses sight to communicate
- tactile
-
uses touch to communicate
- acoustic
-
uses sound to communicate
- chemical
-
uses smells or other chemicals to communicate
- cryptic
-
having markings, coloration, shapes, or other features that cause an animal to be camouflaged in its natural environment; being difficult to see or otherwise detect.
- herbivore
-
An animal that eats mainly plants or parts of plants.
- frugivore
-
an animal that mainly eats fruit
- granivore
-
an animal that mainly eats seeds
References
Mittermeier, R., W. Konstant, F. Hawkins, E. Louis, O. Langrand, J. Ratsimbazafy, R. Rasoloarison, J. Ganzhorn, S. Rajaobelina, I. Tattersall, D. Meyers. 2006. Lemurs of Madagascar . Washington, D.C.: Conservation International, Tropical Field Guide Series.
Nowak, R. 1999. Walker's Mammals of the World . Baltimore, Maryland: The Johns Hopkins University Press.
A Handbook of Living Primates J.R. Napier and P.H. Napier 1967 Academic Press.
Grzimek's Encyclopedia of Mammals vol. 2 Dr. Bernhard Grzimek 1990 McGraw-Hill Publishing Company.
The Encyclopedia of Mammals Dr. David MacDonald 1984 Facts on File Publications.
The Evolution of Primate Behavior Alison Jolly 1972 Macmillan Publishing Company.