Fat-Tailed Dwarf Lemur | |
---|---|
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Mammalia |
Order: | Primates |
Suborder: | Strepsirrhini |
Family: | Cheirogaleidae |
Genus: | Cheirogaleus |
Species: | C. medius |
Binomial name | |
Cheirogaleus medius É. Geoffroy, 1812 [3] | |
Fat-tailed dwarf lemur range [1] | |
Synonyms | |
|
The fat-tailed dwarf lemur (Cheirogaleus medius), also known as the lesser dwarf lemur, western fat-tailed dwarf lemur, or spiny forest dwarf lemur, is endemic to Madagascar.
The fat-tailed dwarf lemur is 8–9 in (200–230 mm) long from its head to the end of its torso, with an 8–11 in (200–280 mm) tail extending beyond that. It weighs 4–10 oz (110–280 g). It has a lifespan of 4-11 years in the wild and 18 years in captivity. It uses its tail to store fat reserves for torpor. [4]
Recent research has shown that C. medius hibernates (or aestivates), even though in the tropical winter of Madagascar, temperatures remain high. It is the first tropical mammal and only primate in which hibernation has been demonstrated. However, the Malagasy winter is dry, and it appears that the lemur is avoiding the drought. It can hibernate for seven months. Unlike animals that hibernate in temperate regions, the lemur does not control its body temperature while hibernating, and if the tree hole in which it is sleeping is not well insulated, its body temperature fluctuates in accordance with the outside temperature. [5] During torpor, this lemur has been found to periodically enter REM sleep; non-REM sleep has not been observed, a pattern opposite that found in hibernating ground squirrels. [6] The REM sleep episodes occurred during periods of higher ambient temperature (averaging 27 C, versus an average of 20 C during nonsleeping intervals while in torpor). [6]
C. medius has a significantly longer lifespan than other strepsirrhinine or nonstrepsirrhinine primates of similar size, and this longevity is thought to be related to its status as part of the only primate genus that is an obligatory hibernator. Its maximum lifespan in captivity is nearly 30 years. [7]
Like other fat-tailed lemurs, C. medius is able to store fat in its tail, and this provides a source of energy during its period of dormancy.
Although most C. medius live in areas where the environment is dry, there are those who live in tropical rain forest. Through research, it is understood that these animals hibernation period is linked to their reproduction strategies. In the rainforest these lemurs are in more of an active state than they would be in a dry forest. This level of high activity from the lemurs is linked to higher reproduction rates according to Dr. Lahann. [8]
Between 2000 and 2009, a population of dwarf lemur was known as a separate species, the southern fat-tailed dwarf lemur (Cheirogaleus adipicaudatus). It was described by taxonomist Colin Groves as having a pelage coloration that is dark dorsally and gray ventrally, with a vaguely expressed dorsal stripe running down the back, a relatively short white median facial stripe, and black eye-rings. [9] However, in 2009, Groeneveld et al. demonstrated genetically that Cheirogaleus adipicaudatus was a synonym of Cheirogaleus medius, so the southern fat-tailed dwarf lemur is no longer recognized as a species. [10] [11]
This species is nocturnal, with a diet of insects, other small animals, fruits and flowers. [12]
The fat-tailed lemur is the only known primate to hibernate for extended periods of time, up to seven months. It performs this torpor during the dry season to minimise the impacts of droughts. During the wet season, it gorges on food, accumulating a fat reserve in its tail. By the beginning of torpor, the tail accounts for up to 40% of its body weight. [13]
The Cheirogaleidae are the family of strepsirrhine primates containing the various dwarf and mouse lemurs. Like all other lemurs, cheirogaleids live exclusively on the island of Madagascar.
Hibernation is a state of minimal activity and metabolic depression undergone by some animal species. Hibernation is a seasonal heterothermy characterized by low body-temperature, slow breathing and heart-rate, and low metabolic rate. It is most commonly used to pass through winter months – called overwintering.
The woolly lemurs, also known as avahis or woolly indris, are nine species of strepsirrhine primates in the genus Avahi. Like all other lemurs, they live only on the island of Madagascar.
Lemurs are wet-nosed primates of the superfamily Lemuroidea, divided into 8 families and consisting of 15 genera and around 100 existing species. They are endemic to the island of Madagascar. Most existing lemurs are small, have a pointed snout, large eyes, and a long tail. They chiefly live in trees and are active at night.
The gray mouse lemur, grey mouse lemur or lesser mouse lemur is a small lemur, a type of strepsirrhine primate, found only on the island of Madagascar. Weighing 58 to 67 grams, it is the largest of the mouse lemurs, a group that includes the smallest primates in the world. The species is named for its mouse-like size and coloration and is known locally as tsidy, koitsiky, titilivaha, pondiky, and vakiandry. The gray mouse lemur and all other mouse lemurs are considered cryptic species, as they are nearly indistinguishable from each other by appearance. For this reason, the gray mouse lemur was considered the only mouse lemur species for decades until more recent studies began to distinguish between the species.
The pygmy mouse lemur, also known as Peters' mouse lemur or dormouse lemur, is a primate weighing only 43–55 g (1.5–1.9 oz); it is the second smallest of the mouse lemurs. Its dorsal side is a rufous-brown colour, and creamy-white ventrally. It lives in dry deciduous forests of western Madagascar. It has been captured in the Tsingy de Bemaraha Nature Reserve, the Andramasy forests north of Belo sur Tsiribihina, and the border of heavily degraded deciduous forest and savanna at Aboalimena. It has also been found in other habitats, in mangroves in two localities.
Goodman's mouse lemur is a species of mouse lemur from the region near Andasibe in eastern Madagascar. The species is named in honor of primatologist Steven M. Goodman. "Lehilahytsara" is a combination of the Malagasy words which mean "good" and "man". The finding was presented August 10, 2005, along with the discovery of the northern giant mouse lemur as a separate species.
The greater dwarf lemur, or the Geoffroy's dwarf lemur, is a lemur that is widely distributed over the primary and secondary forests near the eastern coast of Madagascar. They are also found in northern parts of Madagascar. Greater dwarf lemurs live in forests and dry scrub areas. The head and body of the greater dwarf lemur can range from 167 to 264 millimeters in length, and 164 to 600 grams. Their tails can range from 195 to 310 millimeters in length.
The furry-eared dwarf lemur, or Crossley's dwarf lemur, only found on the island of Madagascar, as with all other lemurs. It has a pelage coloration that is red-brown dorsally and gray ventrally. The eye-rings of this species are blackish and the ears are black inside and out. Cheirogaleus crossleyi species are obligated to hibernate during periods of food scarcity on the island of Madagascar. Cheirogaleus crossleyi species specifically undergo drastic fluctuations in temperature during hibernation.
The reddish-gray mouse lemur also known as the gray-brown mouse lemur or rufous-gray mouse lemur, is a small, solitary-but-social, nocturnal and omnivorous primate from the Western Madagascar in the region around Beza Mahafaly Reserve, north to Lamboharana. Like the other lemur species, the reddish-grey mouse lemur is endemic to Madagascar. They generally live in the drier regions of the island. It is categorized as least concerned in the IUCN Red List.
The dwarf lemurs are the lemurs of the genus Cheirogaleus. All of the species in this genus, like all other lemurs, are native to Madagascar.
Sibree's dwarf lemur is a small nocturnal lemur endemic to Madagascar.
The Kirindy Mitea National Park is a national park on the coast of the Mozambique Channel, in south-west Madagascar. The 72,200 hectares park contains many endemic animals and plants and claims to have the greatest density of primates in the world.
The southern woolly lemur, or southern avahi, has been recently recognized as a separate species of woolly lemur in 2006 by Zaramody et al. It is a nocturnal and pair-living species. Groups can range from 2 to 5 individuals. A study in Sainte Luce forest revealed home range varied from 2.2 to 3.5 ha and that males can have larger home range and cover longer daily distances than females, in agreement with the territory defence and mate guarding hypotheses.
The Lavasoa dwarf lemur is a small, nocturnal strepsirrhine primate and a species of lemur that is endemic to three small, isolated patches of forest on the southern slopes of the Lavasoa Mountains in southern Madagascar. Fewer than 50 individuals are thought to exist. Its habitat lies in a transitional zone between three ecoregions: dry spiny bush, humid littoral forest, and humid forest. First collected in 2001 and thought to be a subpopulation of the furry-eared dwarf lemur (C. crossleyi), it was not formally described until 2013. It is one of six species of dwarf lemur, though the research that identified it also suggested the existence of many more new species.
The Montagne d'Ambre dwarf lemur or Andy Sabin's dwarf lemur is a species of dwarf lemur known only from Amber Mountain National Park and the surrounding area in northern Madagascar. It was identified in 2005, but not formally described until 2015. It is an endangered species, at risk from deforestation and possibly hunting from nearby human populations.
The Ankarana dwarf lemur or Sheth's dwarf lemur is a species of dwarf lemur, part of the C. medius group, known only from northern Madagascar. It has been found in two reserves as well as two protected areas. It was identified in 2014, but not formally described until 2016. Its conservation status has not been determined, but it is at risk from habitat destruction due to daily resource extraction by local human populations.
Groves' dwarf lemur is a species of dwarf lemur known from Ranomafana and Andringitra national parks and surrounding areas in southeastern Madagascar. The identification was based on comparison of mitochondrial and nuclear gene sequences with other members of the C. crossleyi group. Individuals from this clade first came under genetic study in 1999 and were recognized as a new species in 2014, but it was not formally described until 2017. The lemur was named after mammalologist Colin Groves. Known from altitudes from 754 to 999 m, it is significantly larger than other members of the C. crossleyi group, with a 20 cm body length, a 29 cm tail, and a weight of 0.41 kg. While the conservation status of the new species has not yet been assessed, its presence in several national parks does not guarantee that it will not be threatened by deforestation ongoing on the island, or possibly by hunting.