Cheirogaleus sibreei (Forsyth Major, 1896)

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 : 61

24.

Sibree’s Dwarf Lemur

Cheirogaleus sibreei

French: Chirogale de Sibree / German: Sibree-Fettschwanzmaki / Spanish: Lémur enano de Sibree

Taxonomy. Chirogale sibreei Forsyth Major, 1896 ,

Madagascar, Ankeramadinika, one day east of Antananarivo.

This species is one of five dwarf lemurs identified in publications by C. P. Groves in 2000 and 2001 as belonging to the C. major group. It was first described by C. Forsyth Major in 1896 but subsequently considered a junior synonym of C. major . Groves resurrected this species based on four skins in museum collections (type specimen in the British Museum, a skin from Imerina in the Humboldt Museum, Berlin, and two specimens from Pasandava Bay, north of the Ampasindava Peninsula, in Naturalis (Rijksmuseum in Leiden). No more recent information was available concerning its range in the wild until it was identified in a small patch of forest in Tsinjoarivo by M. Blanco and coworkers in 2009. Monotypic.

Distribution. CE Madagascar,in a forest patch of 228 km? at Andasivodihazo at about 1660 m above sea level and Ankadivory at about 1470 m above sea level; it may be restricted by the Onive and Mangoro rivers, Anjozorobe, and the corridor to the W half of the Tsinjoarivo forest above 1400 m, in an area ofless than 2000 km?,

Descriptive notes. Head-body 20.5-23.5 cm,tail 22-26.5 cm; weight 272 g. Sibree’s Dwarf Lemuris grayish-fawn above and on the cap, with or without a darker dorsal median line. There is light gray or creamy fur (with whitish tips and darker roots) on the ventrum; this light coloration continues cranially as bands extending onto the sides of the neck but not the back, although it does extend up the flanks and along the outsides of the thighs. Orbits are surrounded by distinct, broad, and very black eye-rings. There may be thin extensions of this black coloration (or none at all) delineating sides of the muzzle, but the dominant color of the muzzle is only slightly grayer than the dorsal fur and very uniform. The rhinarium tends to be pink. Ears are naked, and pinnae are dark with sparse hair on their inner and outer surfaces. Hands and feet are pink ventrally and gray-brown dorsally.

Habitat. High-altitude rainforest above elevations of 1400 m.

Food and Feeding. There is no specific information available for this species, but undoubtedly fruits, flowers, and insects are eaten, and possibly other items identified in the diets of other members of the genus.

Breeding. There is no information available for this species.

Activity patterns. Sibree’s Dwarf Lemur is nocturnal and arboreal.

Movements, Home range and Social organization. There is no information available for this species.

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, Sibree’s Dwarf Lemur was assessed as critically endangered dueto its very small area of occupancy ofless than 10 km2, as well as ongoing decline. The range of Sibree’s Dwarf Lemur is the smallest of any of the dwarf lemurs. It is restricted to just a very few subpopulations along the western margin of the eastern rainforest corridor between the Onive and Mangoro rivers. Groeneveld and coworkers reported on the status of these forests; while the lower parts near the plateau escarpment are remote and reasonably undisturbed, the higher areas are flatter, continuous with the plateau, and broadly accessible to “substantial human settlement.” The forest cover in this western part of Tsinjoarivo has been reduced to about one-halfits original extent, and it is highly fragmented. The forest there is slated for future protection, but there are no existing safeguards to ensure its permanence. Habitat loss and fragmentation are a threat to the survival of Sibree’s Dwarf Lemur . It is not known to occur in any protected areas.

Bibliography. Blanco et al. (2009), Groeneveld et al. (2010), Groves (2000a, 2001), Mittermeier et al. (2010), Rasolofoson, Rakotondratsimba, Rakotoirainy, Rakotozafy et al. (2007), Rasolofoson, Rakotondratsimba, Rakotoirainy, Rasolofoharivelo et al. (2007).

Figures

23. Fat-tailed Dwarf Lemur (Cheirogaleus medius), 24. Sibree’s Dwarf Lemur (Cheirogaleus sibreei), 25. Greater Dwarf Lemur (Cheirogaleus major), 26. Crossley’s Dwarf Lemur (Cheirogaleus crossleyi), 27. Lesser Iron-gray Dwarf Lemur (Cheirogaleus minusculus)

Distribution. CE Madagascar,in a forest patch of 228 km? at Andasivodihazo at about 1660 m above sea level and Ankadivory at about 1470 m above sea level; it may be restricted by the Onive and Mangoro rivers, Anjozorobe, and the corridor to the W half of the Tsinjoarivo forest above 1400 m, in an area ofless than 2000 km?,