When feeding, red-bellied lemurs employ a sentinel to keep watch for predators. If a bird of prey or some other predator is detected, the sentinel will utter several low grunts. The other members of the group will either freeze for periods up to 15 minutes or they will take cover. The are preyed upon by fossas (the largest carnivore in Madagascar) and raptors (Preston-Mafham, 1992; Stony Brook State University of New York, 1999). They are also hunted by humans and taken by introduced dogs and cats.
Known Predators:
Red-bellied lemurs are sexually dichromatic. Females have white bellies with white markings on the neck and chin, whereas males are mostly brown with dramatic white eye patches and a scent gland located on the forehead. Both sexes both have a black tail.
The head and body length is from 36 to 42 cm and the tail length is 46 to 54 cm. These lemurs usually weigh between 2 and 3 kg and are approximately the size of a house cat (SUNY, 1999; Schmid & Smolker, 1998).
Range mass: 2 to 3 kg.
Range length: 36 to 54 cm.
Sexual Dimorphism: sexes colored or patterned differently
Other Physical Features: endothermic ; bilateral symmetry
Red-bellied lemurs live 20 to 25 years in the wild (Duke University Primate Center, 1999).
Range lifespan
Status: wild: 20 to 25 years.
Average lifespan
Status: captivity: 20 years.
This lemur mainly inhabits rainforest regions, at medium to high altitudes (Macdonald, 1984; Nowak, 1999).
Habitat Regions: tropical ; terrestrial
Terrestrial Biomes: rainforest
Red-bellied lemurs, Eulemur rubriventer, live in the eastern rainforest zone of Madagascar (Nowak, 1999).
Biogeographic Regions: ethiopian (Native )
Other Geographic Terms: island endemic
The diet of red-bellied lemurs consists mainly of flowers, fruits and leaves of 67 identified plant species. They also eat some invertebrates. When they eat toxic millipedes, they drool on them first, which may help to neutralize the toxins so these invertebrates are edible. Red-bellied lemurs, as well as other lemur species, may also eat soil (Nowak, 1999; Preston-Mafham, 1992).
Animal Foods: insects
Plant Foods: leaves; seeds, grains, and nuts; fruit; flowers
Primary Diet: herbivore (Folivore , Frugivore )
Rred-bellied lemurs have been used in many behavioral studies. The Malagasy names for these animals are: Tongona, Barimas, and Soamiera.
As in other primate species, communication is complex and occurs in a variety of ways. In addition to vocal communication, E. rubriventer uses chemicals to communicate. The prominent forehead scent gland of males is used to help mark territories. Facial expressions and body postures are some of the visual signals these primates use in communication. Finally, tactile communication, through grooming, mating, play, and aggression, also occurs.
Communication Channels: visual ; tactile ; acoustic ; chemical
Perception Channels: visual ; tactile ; acoustic ; chemical
All species in this genus are endangered. The red-bellied lemur is listed as vulnerable by IUCN and is on Appendix I of CITES. Populations are estimated between 10,000 and 100,000 animals, and are thought to be declining due to the rapid loss of rainforest habitat in Madagascar (Nowak, 1999). All members of the Lemuridae are listed as endangered by the U.S. Federal government.
US Federal List: endangered
CITES: appendix i
IUCN Red List of Threatened Species: vulnerable
There are no negative effects of red-bellied lemurs on humans.
Red-bellied lemurs, as well as the other species of lemurs, are charismatic and unique animals, making them valuable for ecotourism. These animals have also been used in behavioral research. They are sometimes hunted for food.
Positive Impacts: food ; ecotourism ; research and education
These lemurs play a role in seed dispersal and germination from seeds contained in the feces (Dew & Wright 1998).
Ecosystem Impact: disperses seeds
Red-bellied lemurs are one of the few lemur species to form monogamous pair bonds. These form the core of the social group, which typically consists of the mated pair and their offspring. (Duke University Primate Center, 1999)
Mating System: monogamous
Red-bellied lemurs have a gestation period of 127 days and give birth from September to October. There is usually a single young born, though twins sometimes occur, and birth weight is 60 to 70 grams. An estrous cycle lasts one month and estrous lasts 1 to 2 days (Schmid & Smolker, 1998). Mothers wean their young around the age of 5 months.
Sexual maturity is reached at about 2 years of age. (Duke University Primate Center, 1999)
Breeding interval: These lemurs are capable of breeding annually.
Breeding season: Mating occurs from May through June with births occuring from September to October.
Range number of offspring: 1 to 2.
Average gestation period: 127 days.
Average weaning age: 5 months.
Average age at sexual or reproductive maturity (female): 2 years.
Average age at sexual or reproductive maturity (male): 2 years.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization ; viviparous
Average birth mass: 85.5 g.
Average gestation period: 130 days.
Average number of offspring: 1.
Both male and female parents care for their offspring. The mother nurses and carries the infant for the first 2 weeks of life. From 2 weeks to 5 weeks of age, the young are cared for equally by both parents, although nursing is only accomplished by the mother. After 5 weeks of age, the mother often rejects the young, leaving the father to care for them until they are about 100 days old.
Parental Investment: altricial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Male, Female); pre-weaning/fledging (Provisioning: Female, Protecting: Male, Female); pre-independence (Protecting: Male)
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.[4]
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.[5][6] 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.
The various Malagasy names for the red-bellied lemur include tongo, tagona, halomena, kirioka, and soamiera. In the French scientific literature (Madagascar's second official language is French, due to prior colonisation by France), the species is called lémur à ventre rouge.
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 34 to 40 cm (13 to 16 in) (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 1 m (3 ft 3 in). Typical body mass of a mature individual ranges from 1.6 to 2.4 kg (3.5 to 5.3 lb).[7] The male has scent glands atop his head. Lifespans may easily exceed 20 years for both sexes.
E. rubriventer occurs as far north as the Tsaratanana Massif at an elevation of 2,400 m (7,900 ft), then southerly to the Manampatrana River in a narrow strip of eastern Madagascar rainforest.[3] 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 mid-range, the common brown lemur E. fulvus; and in its southern range, the red-fronted brown lemur E. rufus and the gray-headed lemur E. cinereiceps. E. rubriventer is, however, easily distinguished from these relatives by the male's distinctive white eye "tear drops" and the rich darkness of the fur of both sexes. A distinction of appearance occurs within E. rubriventer in that northern range males (e.g. Mantadia National Park north) have a more distinctive reddish belly than the southern range counterparts, as in Ranomafana National Park.[8]
The forest type within the red-bellied lemur's range is characterized by dense evergreen vegetation, with a canopy of 25 to 35 m (82 to 115 ft). Typical canopy genera include Dalbergia, Diospyros, Ocotea, Symphonia, and Tambourissa; emergents of Canarium, Albizia and Brochoneura acuminata are also present. The eastern lowland forests also have a rich diversity of Pandanus, bamboo, and epiphytic orchid species.
The red-bellied lemur aggregates in monogamous groups ranging from two to 10 individuals. It is one of the few lemurs to be recognized as cathemeral, having both diurnal and nocturnal activity patterns. The home range is estimated to be 25 to 35 acres (10 to 14 ha) with a typical density of five animals per acre. Groups are typically cohesive as they move within their home range, foraging on over 30 species of plants. Considered by some to be a frugivore, it also feeds on leaves, nectar, and flowers of many plant species; this lemur is believed to be a useful and efficient seed disperser.
A typical and maximum frequency of births is one offspring per female per year, with initial year infant mortality around 50%. Births normally occur in October and November (early summer in this Southern Hemisphere habitat). The young use their prehensile instincts to attach to the mother and father alternately for the first 33 to 37 days of life. At this point, the mother often refuses further transport services, whilst the father may continue to provide such for another 9 weeks.
Modern feeding habits have expanded the species' diet to the introduced "Chinese" (actually Brazilian) guava (Psidium cattleyanum). Groups of the red-bellied lemur have become somewhat habituated to humans along certain trail areas in Ramomafana National Park (around Belle Vue) starting in May and June, and much rarer in some lower trail areas of Montadia National Park starting in April. In both instances, the species exhibits a tame behaviour to approaching humans who are silent and walk softly. The animals will descend from the trees to within 2–3 m (6.6–9.8 ft), staring back at the humans with equal curiosity allowing themselves to be photographed as they cling to vertical trunks of saplings, and occasionally engaging in a terrestrial scamper.
E. rubriventer occurs in five national parks and seven special reserves in eastern Madagascar, but is classified as vulnerable (IUCN Red List) due to ongoing habitat reduction from slash-and-burn farming, illegal logging, and even hunting. The species is the subject of current study in its natural habitat as well as in captivity in research centers such as the Duke Lemur Center.
Male 
Female 
Juvenile 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.
