Avahi occidentalis (Lorenz, 1898)

Russell A. Mittermeier, Anthony B. Rylands & Don E. Wilson, 2013, Indriidae, Handbook of the Mammals of the World – Volume 3 Primates, Barcelona: Lynx Edicions, pp. 142-175 : 166

7.

Western Woolly Lemur

Avahi occidentalis

French: Avahi occidental / German: Westlicher Wollmaki / Spanish: Lémur lanudo occidental

Other common names: Lorenz von Liburnau’s Woolly Lemur, Western Avahi

Taxonomy. Avahis laniger occidentalis Lorenz, 1898 ,

Madagascar, Ambondrobe, NE of Bombetoka Bay (15° 38’ S, 46° 24’ E).

This species is monotypic.

Distribution. NW Madagascar, the core distribution seems to be to the N and E of the Betsiboka River as far as the Bay of Narinda, and this is also the species present in Ankarafantsika National Park. The isolated population farther N in the Ankarana region may also be this species, but, in between, the Sambirano Woolly Lemur (A. unicolor ) inhabits both the Ampasindava Peninsula and the Sambirano region, including the Manongarivo Special Reserve.

Descriptive notes. Head-body 26.9-30.3 cm, tail 30.7-37.7 cm; weight 830-1000 g. The Western Woolly Lemur is one of the smallest woolly lemurs and, consequently, among the smallest members of the family Indriidae . It is lighter in color than the Eastern Woolly Lemur (A. lan:ger), with dense, tightly curled fur of the back a light to medium gray, sometimes flecked with brown or olive, becoming paler toward the rear. Typically, the tail also is gray, but it is sometimes reddish. The face, throat, and cheeks are pale, not brown as in the Eastern Woolly Lemur.

Habitat. Tropical dry deciduous primary and secondary forests.

Food and Feeding. Young leaves and buds seem to be preferred food items of the Western Woolly Lemur, probably accounting for three-quarters of the dietary intake. More than 20 plant species have been documented as food items, many of which do not appear to be common in the surrounding forests.

Breeding. There is no information available for this species.

Activity patterns. The Western Woolly Lemur is nocturnal and arboreal. Feeding bouts occur more toward the beginning and end of the night, and individuals tend to be inactive in between.

Movements, Home range and Social organization. The Western Woolly Lemurlives in cohesive pairs. In the dry forests of Ankarafantsika, groups of up to five individuals, typically consisting of an adult pair and immature offspring, occupy home ranges of 1-2 ha. Territorial defense appears to be less vigorous and less vocal than in eastern rainforest species of Avahi , with greater overlap between neighboring groups. The Western Woolly Lemur exhibits female dominance over males. Density has been estimated at 67 ind/km?in Ankarafantsika.

Status and Conservation. CITES Appendix I. Classified as Endangered on The [UCN Red List. The Western Woolly Lemur has a limited distribution, occurs in fragmented populations, and has experienced recent declines in habitat and overall numbers.It is threatened by forest destruction, mainly due to annual burning to create new pasture, and it is also hunted to some degree. Field surveys and genetic studies of populations of Avahi at Ankarana are needed to determine the taxonomic and conservation status of woolly lemurs in that area. The Western Woolly Lemur occurs in Ankarafantsika National Park, Bora Special Reserve, and Mariarano Classified Forest. It may perhaps be the species found in the Ankarana Special Reserve, although this has not been confirmed.

Bibliography. Albignac (1981b), Bauchot & Stephan (1966), Ganzhorn (1988), Lei et al. (2008), Mittermeier et al. (2010), Nicoll & Langrand (1989), Ramanankirahina et al. (2011), Randrianambinina, Rasoloharijaona et al. (2003), Razanahoera-Rakotomalala (1981), Schmid & Smolker (1998), Sterling & McFadden (2000), Thalmann (2001), Thalmann & Geissmann (2000), Warren (1997), Warren & Crompton (1997a), Zaramody et al. (2006).

Figures

On following pages: 12. Crowned Sifaka (Propithecus coronatus); 13. Coquerel’s Sifaka (Propithecus coquerell); 14. Tattersall’s Sifaka (Propithecus tattersall); 15. Diademed Sifaka (Propithecus diadema); 16. Milne-Edwards's Sifaka (Propithecus edwardsi); 17. Silky Sifaka (Propithecus candidus); 18. Perrier’s Sifaka (Propithecus perrieri).

Distribution. NW Madagascar, the core distribution seems to be to the N and E of the Betsiboka River as far as the Bay of Narinda, and this is also the species present in Ankarafantsika National Park. The isolated population farther N in the Ankarana region may also be this species, but, in between, the Sambirano Woolly Lemur (A. unicolor ) inhabits both the Ampasindava Peninsula and the Sambirano region, including the Manongarivo Special Reserve.