The red-bellied lemur (Eulemur rubriventer) is a medium-sized strepsirrhine primate with a luxuriant chestnut brown coat. This lemur is endemic to eastern Madagascan rainforests and is distinguished by patches of white skin below the eyes, giving rise to a "teardrop" effect, particularly conspicuous in the male. The species, first identified in 1850, exhibits diurnal behaviour and marked sexual dimorphism. The red-bellied lemur has been studied extensively since the mid-1980s, primarily in Ranomafana National Park. This lemur species is designated as vulnerable according to the IUCN Red List, due to threats endangering habitats from slash-and-burn agriculture in Madagascar. Etymology The various Malagasy names for the red-bellied lemur include , , , , and . In the French scientific literature (Madagascar's second official language is French, due to prior colonisation by France), the species is called . Description Being sexually dimorphic, the male of the species exhibits a medium-long, dense dorsal coat of intense chestnut brown. Ventrally, he is lighter and redder in hue, while his tail, muzzle and head are black. For the female, the dorsal area and tail resemble the male, whereas the ventral fur is a contrasting white-cream colour. Facial markings are similar to the male, except that "tear drops" are less exaggerated and spiry thick cheek hairs of the male are absent. Whereas the genus Eulemur relatives may exhibit ear tufts or a furry beard, these features are absent for E. rubriventer, which has thickened fur around its ears, lending a fuller facial appearance. The adult red-bellied lemur has a length of (excluding tail) and a tail length which is almost twenty percent longer than the body itself; that is, body plus tail length may attain a total length of almost . Typical body mass of a mature individual ranges from . The male has scent glands atop his head. Lifespans may easily exceed 20 years for both sexes. Range and distribution E. rubriventer occurs as far north as the Tsaratanana Massif at an elevation of , then southerly to the Manampatrana River in a narrow strip of eastern Madagascar rainforest. In previous eras, its range extended further south to the Mananara River. This species is distributed thinly and is restricted only to intact rainforest; it does not occur at all on the Masolala Peninsula. The red-bellied lemur is sympatric with four other Eulemur species: in the extreme north of its range, the white-headed lemur E. albifrons; at