Allocebus trichotis (Gunther, 1875)

Russell A. Mittermeier, Anthony B. Rylands & Don E. Wilson, 2013, Cheirogaleidae, Handbook of the Mammals of the World – Volume 3 Primates, Barcelona: Lynx Edicions, pp. 28-65 : 59

22.

Hairy-eared Dwarf Lemur

Allocebus trichotis

French: Allocebe / German: Bischelohrmaki / Spanish: Lémur enano de orejas peludas

Other common names: Hairy-eared Mouse Lemur

Taxonomy. Chirogaleus [sic] trichotis Gunther, 1875 ,

Madagascar, between Tamatave and Morondava.

This species is monotypic.

Distribution. NE & EC Madagascar, but precise limits unknown.

Descriptive notes. Head-body 13-16 cm, tail 14-20 cm; weight 79 g. The body of the Hairy-eared Dwarf Lemur is rosy brownish-gray above and grayish-white below, with black areas immediately surrounding the eyes. A pale white stripe may be present on the nose, extending from between the eyes to the tip, and cheeks are white. There are conspicuous plumes of wavy dark brown hair covering the rather small ears. The tail is long and the same color as the upper body, becoming darker and bushier atits end.

Habitat. Mainly found in primary tropical moist lowland and mid-altitude rainforest from near sea level up to 1000 m, although some populations appear to occur in montane forest up to 1600 m. Hairy-eared Dwarf Lemurs are usually spotted in tangles of brush or lianas, and they forage in the low levels of the forest canopy. They appear to tolerate moderate levels of human activity.

Food and Feeding. Diet of the Hairy-eared Dwarf Lemur consists of nectar,fruit, gums (primarily of Terminalia , Combretaceae ), young leaves, honey, and insects (especially locusts). Breeding. Estrus is believed to occur at the beginning of the wet season in November-December, with births taking place in January-February. Gestation length and longevity are unknown.

Activity patterns. Nocturnal and arboreal. According to earlier reports, prior to undergoing torpor in the cooler, less rainy austral winter (May/June-September/October), they accumulate large amounts of fat, and their body weights peak at ¢.140% of the minimum. During this supposed torpor, they apparently use most oftheir fat reserves, but they emerge ready to breed. In contrast, more recent research indicates that Hairyeared Dwarf Lemurs do not undergo periods of torpor; this research did not indicate that significant weight gain occurred prior to the winter months.

Movements, Home range and Social organization. Relatively little was known about the behavior and ecology of the Hairy-eared Dwarf Lemur until recently. It has been observed singly and in pairs (presumably male and female) with offspring, and it appears to have much larger home ranges (5-4-15-4 ha) than other cheirogaleids. Groups of two to six nest in the holes of larger trees and prefer to line the nest with dry plant material, even covering them with it in captivity. Individuals use fourto five tree holes, showing high nest fidelity. It will share a tree hole with White-tailed Tree Rats (Brachytarsomys albicauda). Individuals are often seen in tangles of brush or lianas, and they evidently forage at low levels in the forest canopy. It appears to be very rare wherever it occurs, with an estimated density of 11-19 ind/km? in the one study that has been conducted.

Status and Conservation. CITES Appendix I. Classified as Data Deficient on The IUCN Red List. However, at the IUCN/SSC Lemur Red-Listing Workshop held in July 2012, the Hairy-eared Dwarf Lemur was assessed as vulnerable due to an ongoing and predicted population decline of more than 30% over 10 years. It is found in widely scattered localities at notably low densities. Up until 1989, it had been sighted only along the Mananara River, and they were thought to be restricted to lowland rainforests in that area. Since 1994, however, their presence has been documented in various national parks and otherforests in east-central and north-eastern Madagascar. Overall, sightings have been few (probably no more than a few dozen in total). Range-wide surveys are needed to assess population densities, and more detailed field studies should also be carried out to complementthe single in-depth study available. A detailed long-term study would also be highly desirable to gain a better understanding of its behavior and ecology. Threats include loss of habitat and hunting and trapping in certain regions. In 2002, the estimated world population was less than 1000 individuals. It occurs in five national parks (Mananara-Nord, Mantadia, Marojejy, Masoala, and Zahamena), the Zahamena Strict Nature Reserve, three special reserves (Analamazaotra, Anjanaharibe-Sud, and Marotandrano), and Ambatovy Classified Forest.

Bibliography. Biebouw (2009), Biebouw etal. (2009), Garbutt (2001), Goodman & Raselimanana (2002), Groves (2001), Meier & Albignac (1989, 1991), Mittermeier et al. (2010), Nowak (1999), Pastorini et al. (2001), Petter-Rousseaux & Petter (1967), Rakotoarison (1995a, 1995b), Rakotoarison et al. (1997), Roos et al. (2004), Rumpler et al. (1995), Schmid & Smolker (1998), Schiitz & Goodman (1998), Sterling & Rakotoarison (1998), Yoder (1996).

Figures

20. Coquerel’s Giant Mouse Lemur (Mirza coquereli), 21. Northern Giant Mouse Lemur (Mirza zaza), 22. Hairy-eared Dwarf Lemur (Allocebus trichotis)

Distribution. NE & EC Madagascar, but precise limits unknown.