GEOFFROY'S DWARF LEMUR
Geographic Distribution and Habitat
Geoffroy’s dwarf lemurs are found in northeastern and western central Madagascar. They can be spotted from the southeastern tip to the northeastern tip, with a small population isolated inland in the west-central part of the island. Geoffroy’s dwarf lemurs, which are also known as greater dwarf lemurs, are sympatric with fat-tailed dwarf lemurs (C. medius) and Crossley’s dwarf lemurs (C. crossleyi) in the southern region, though they do not occupy the same exact forests.
Geoffroy’s dwarf lemurs have been observed in a wide range of habitats, from humid forests within the Vohimena and Anosy mountains to the littoral forest of Mandena. Madagascar’s eastern lowland and montane forests are generally well-provisioned with water and food during seasons when the western regions are severely impacted by drought. Their range is from sea level to 5,905 ft (1,800 m) above it.
Size, Weight, and Lifespan
Geoffroy’s dwarf lemurs weigh nearly one pound (450 g). The length of their body is anywhere from 6.5 in (16.7 cm) to 10.3 in (26.4 cm) and their tail is even longer, at 7.6 in (19.5 cm) to 12.2 in (31.0 cm). They can live up to fifteen years.
Short, squat, and fuzzy-looking primates with dense fur and a long, bushy tail, the pelage of Geoffroy’s dwarf lemurs is gray or reddish-brown, with the exception of a light gray face with dark circles around their eyes. They have thin, protruding ears and a tiny pointed snout.
At the end of the rainy season, their tails are often swollen with fat (up to as much as 30% of its total body mass!) in preparation for torpor.
Geoffroy’s dwarf lemurs are omnivorous. Their diet consists mostly of fruits, flowers, and nectar, with the occasional insect or small vertebrate. Flower nectar is consumed from November to December.
What Does It Mean?
Physically adapted to living primarily or exclusively in trees.
The time of pregnancy from conception until birth.
The process by which a large, continuous stretch of habitat gets divided into smaller, disjointed patches of habitat.
Forests along the coast and cayes featuring salt-tolerant vegetation.
Active at night.
Having a diet that consists of food of both plant and animal origin.
Using four limbs to move about. This word comes from the Latin meaning ‘four feet.’
Occurring or living in the same area; overlapping in distribution.
A sleep-like state in which the body decreases physiological activity.
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Behavior and Lifestyle
A nocturnal species, during during the day, they sleep in nests of twigs, leaves, and grass or hollowed trees with dry leaves for padding. They are arboreal and quadrupedal, even when moving along horizontal tree branches. Geoffroy’s dwarf lemurs are not agile leapers.
During the dry season, they store fat in their tails and become torpid in tree holes and hollows. This torpor lasts for about a month, during which time they can lose up to 3.5 oz (100 g) of weight.
Torpor is a hibernation-like state of inactivity, which allows dwarf lemurs to survive periods of food and water scarcity in the dry season. During this time, the lemur burns through his energy reserves much more slowly than when active. He spends torpor curled up in a ball, often in a hollow tree, surviving on the fat stored in his tail.
Daily Life and Group Dynamics
Generally, Geoffroy’s dwarf lemurs live solitary lives but spend time with other lemurs when resting and grooming during the day. Sleeping groups can sometimes include up to three adult lemurs.
Their home ranges extend up to 9.8 acres (4 ha). Though individual ranges often overlap, dwarf lemurs are not believed to be territorial. Males are generally intolerant of other males.
Not a very vocal species, they occasionally make soft calls to locate other Geoffroy’s dwarf lemurs and produce a loud trill or grunt when disturbed. Infants will produce a squeak to keep in contact with their mother.
Tactile communication includes grooming, playing, and aggressive displays. Urine and feces are used to scent mark limbs of trees.
Reproduction and Family
Shortly after the dry season’s torpor ends, mating begins in October and November. Females give birth to two or three infants in January after a 70-day gestation. Mothers build nests in trees at heights of 19.6–39.3 ft (6–12 m) to give birth to their infants, who are born with full fur and open eyes. Mothers carry their infants in their mouths and by three or four weeks, the infants can start climbing and amble along after their mother. They nurse for about 45 days and become more independent shortly thereafter. Geoffroy’s dwarf lemurs become reproductively mature at 10–14 months of age.
Due to their fruit and nectar diet, Geoffroy’s dwarf lemurs likely help to disperse seeds and help to pollinate plants.
Conservation Status and Threats
Geoffroy’s dwarf lemurs are listed as Vulnerable by the International Union for Conservation Nature (IUCN, 2018), appearing on the IUCN’s Red List of Threatened Species. Prior to the 2018 assessment, however, they were categorized as Data Deficient—that is, there was a need for studies to determine their populations, geographic distribution, and threats (although threats to their habitats were already well known). As a result, there is still quite a lot of research needed specifically about the species in order to achieve a better understanding of them and how to protect them.
Some of those questions have been answered, and we now know that Geoffroy’s dwarf lemurs have been hunted most severely in the northern range, and that their habitat decline and levels of exploitation have warranted a precautionary label of Vulnerable. Their population trend is decreasing, possibly up to 30% over a 24-year period, and they are declining as a species because of fragmentation throughout their range and the extent and quality of their habitat. The IUCN clearly states that more exhaustive studies are necessary to see if Geoffroy’s dwarf lemurs could even qualify as Endangered in the future.
In terms of habitat loss and fragmentation, Geoffroy’s dwarf lemurs are likely affected by the national trends seen all across Madagascar; the island lost 37% of its forest cover from 1973 to 2014, with an annual deforestation rate of 1.1% a year from 2010 to 2014. Now, almost half of Madagascar’s forest is located within less than 330 ft (100 m) from the forest edge, which does not bode well for Geoffroy’s dwarf lemurs because they display lower population densities the closer they are to the forest edge.
The threat Geoffroy’s dwarf lemurs face from hunting is most noticeable in the north, which occurs at a rate of 0.01 to 0.38 per year per household.
Geoffroy’s dwarf lemurs are also prey animals for the ring-tailed mongoose, the Malagasy tree boa, and the Madagascar buzzard.
Geoffroy’s dwarf lemurs are listed on Appendix I of the Convention on International Trade in Endangered Species (CITES). Their habitat overlaps protected areas, like eight national parks (Andohahela, Andringitra, Mananara-Nord, Marojejy, Masoala, Midongy du Sud, Montagne d’Ambre, and Ranomafana), two strict nature reserves (Betampona and Tsaratanana), three special reserves (Anjanaharibe-Sud, Mangerivola, and Pic d’Ivohibe), and in the Mandena Conservation Zone. Geoffroy’s dwarf lemurs are also protected and cared for in the Tzimbazaza Zoo in Antananarivo and the Zurich Zoo.
Biodiversity Conservation Madagascar (BCM) also works to protect Geoffroy’s dwarf lemurs at their Sahafina project site through a “conservation lease” of forest from the Malagasy government and through engaging local communities
Written Rachel Heim, August 2020