Eulemur rubriventer (I. Geoffroy Saint-Hilaire, 1850)

Russell A. Mittermeier, Anthony B. Rylands & Don E. Wilson, 2013, Lemuridae, Handbook of the Mammals of the World – Volume 3 Primates, Barcelona: Lynx Edicions, pp. 90-141 : 137-138

18.

Red-bellied Lemur

Eulemur rubriventer

French: Lémur a ventre roux / German: Rotbauchmaki / Spanish: Lémur de vientre rojo

Taxonomy. Lemur rubriventer I. Geoffroy Saint-Hilaire, 1850 ,

Madagascar, Tamatave.

There is some geographic variation among populations of E. rubriventer . Males from the region of Andasibe (= Périnet) have a more distinctive reddish belly compared with populations found farther south, such as in Ranomafana National Park. Monotypic.

Distribution. E Madagascar, in sparsely scattered populations from the Tsaratanana Massif in the N, S along the thin strip of E rainforest to the Pic d’Ivohibe Special Reserve and the Manampatrana River; at one time the distribution apparently reached as far as the Mananara River. Absent from the Masoala Peninsula.

Descriptive notes. Head—body 35-40 cm, tail 43-53 cm; weight 2 kg. The Red-bellied Lemur is a medium-sized species characterized by its heavy coat of fur, sexual dichromatism, and remarkably small ears that are virtually hidden in the fur. Males are deep chestnut-brown to maroon-red above with a slightly lighter, coppery-red underside. The tail is darker, shading to black like the muzzle, face, and head. Conspicuous patches of white skin form large “tear-drops” below the inner corner of each eye. There is no bushy beard or ear tufts as in other species of Eulemur , but fur around the ears is particularly dense and gives the head a robust appearance. In females, the dorsal coat and tail color are umber, similar to those of the male, but the throat, chest, and abdomen are a highly contrasting yellowy-white that may extend all the way to the cheeks. Facial coloration is also similar in females and males, except that the white patches beneath the eyes are reduced in females. The head of the female appears less robust because it lacks the long bushy cheek hairs of the male. Eyes of both sexes are yellow.

Habitat. Primary and secondary rainforest at middle to high elevations. It occurs at elevations of up to 2400 m on the Tsaratanana Massif. Overits relatively large distribution, the Red-bellied Lemur is sympatric with four other species of Fulemur. the Whitefronted Brown Lemur (FE. albifrons ) in the northern part, the Brown Lemur ( E. fulvus ) toward the middle, and the Red-fronted Brown Lemur (FE. rufifrons ) and the Whitecollared Brown Lemur (FE. cinereiceps ) in the southern part.

Food and Feeding. Diets of the Red-bellied Lemur consist principally of fruits, flowers, nectar, seeds, and leaves from more than 70 plant species, including introduced species such as Chinese guava ( Psidium , Myrtaceae ). It is an important seed-disperser. Invertebrates (especially millipedes) may also form a significant part of the diet at certain times of the year. Individuals typically detoxify large millipedes by rolling them between their hands and salivating on them. Flowers and nectar are consumed more often during warm and wet months of the year.

Breeding. Female Red-bellied Lemur groups usually have only one offspring per year in September—October, after gestation of 123-127 days. Infants are carried on the mother’s belly for the first month or so and then on the back of either the male or female. Females gradually reject their young, but males may carry them up to 100 days of age. Infant mortality is ¢.50%. Weaning occurs at 6-7 months of age.

Activity patterns. The Red-bellied Lemur is arboreal and cathemeral. Breeding pairs with young are active during the day and night throughout the year, depending on the season and availability of food.

Movements, Home range and Social organization. The Red-bellied Lemur has been the subject of several field studies in Ranomaftana National Park since the mid-1980s. Group size is 2-10 individuals, typically containing an adult pair and their offspring. Home range size is 12-15 ha. Groups travel and feed as single units, led primarily by females. Densities of ¢.b ind/km? have been recorded at Ranomafana.

Status and Conservation. CITES Appendix I. Classified as Vulnerable on The IUCN Red List. Although relatively widespread, the Red-bellied Lemur appears to be uncommon throughoutits distribution, and it has declined drastically in number in recent years. It appears to be thinly distributed and restricted to intact forests and is usually considerably rarer than other sympatric species of Eulemur . Main threats are habitat loss from slash-and-burn agriculture, illegal logging, and hunting, which is heavy in some areas. It occurs in five national parks ( Andringitra, Mantadia, Marojejy, Ranomafana, and Zahamena ), two strict nature reserves (Tsaratanana and Zahamena), and six special reserves (Ambatovaky, Analamazaotra, Anjanaharibe-Sud, Mangerivola, Marotandrano, and Pic d’Ivohibe).

Bibliography. Dague & Petter (1988), Glander et al. (1992), Irwin et al. (2005), Meier (1987), Mittermeier et al. (2010), Nicoll & Langrand (1989), Overdorff (1988, 1991), Overdorff & Rasmussen (1995), Schmid & Smolker (1998), Sterling & Ramaroson (1996), Terranova & Coffman (1997).

Figures

8. Brown (Lemur Fulemurfulvus), 9. Rufous Brown Lemur (Eulemur rufus), 10. Red-fronted Brown Lemur (FEulemur rufifrons), 11. White-fronted Brown Lemur (Eulemur albifrons), 12. Sanford’s Brown Lemur (Fulemur sanfordi), 13. White-collared Brown Lemur (Eulemur cinereiceps), 14. Red-collared Brown Lemur (Eulemur collars), 15. Black Lemur (Eulemur macaco), 16. Blue-eyed Black (Lemur Eulemurflavifrons), 17. Crowned Lemur (Eulemur coronatus), 18. Red-bellied Lemur (Eulemur rubriventer), 19. Mongoose Lemur (Eulemur mongoz)

Distribution. E Madagascar, in sparsely scattered populations from the Tsaratanana Massif in the N, S along the thin strip of E rainforest to the Pic d’Ivohibe Special Reserve and the Manampatrana River; at one time the distribution apparently reached as far as the Mananara River. Absent from the Masoala Peninsula.