Hapalemur occidentalis Rumpler, 1975

Scientific name:

Hapalemur occidentalis

Scientist name:

Rumpler, 1975

Malagasy:

Bokombolo, Akomba-Valiha, Bekola, Kofiy, Kitronytrony

English:

Northern Bamboo Lemur

German:

Westlicher Bambuslemur

Other english:

Western Lesser Bamboo Lemur, Western Gentle Lemur

French:

Hapalémur occidental

Family:

LEMURIDAE Gray, 1821

Taxa:

Hapalemur

Species

Identification

Hapalemur occidentalis is similar in size to Hapalemur griseus, with a head-body length of 27–28 cm, a tail length of 36–39 cm, and a total length of 55–67 cm. It appears to show a noteworthy degree of sexual dimorphism in terms of weight, with males averaging 846 g, but females reaching 1,188 g (E. E. Louis Jr., unpubl. data). It is more uniformly gray-brown in coat color than H. griseus, and its face is paler than other members of the genus. Ear length is similar to H. griseus (Groves, 2001; C. P. Groves, pers. comm.). It differs in diploid chromosome number (2n = 58) from H. griseus and H. alaotrensis (2n = 54) (Rabarivola et al., 2007). This species is unlikely to be confused with other diurnal lemurs in its range. It is considerably smaller than any of the Eulemur species and is usually associated with stands of bamboo.

Natural history

Little is known about the ecology and behavior of H. occidentalis. It evidently has a preference for forests that contain bamboo or bamboo vines (Petter and Peyriéras, 1970a; Tattersall, 1982). It has also been reported from degraded habitats in the Sambirano River valley, as well as in patches of bamboo surrounded by agricultural land (Mutschler, 2000). A survey conducted in the Manongarivo Special Reserve found this species to be diurnal and its group size to be small, usually no more than four individuals (Raxworthy and Rakotondraparany, 1988). However, in the Sambirano region, Mutschler (2000) described it as being active mainly at night, and also reported observing a group of six individuals. The birth season is roughly October–January, following a gestation of 137–140 days (Petter and Peyriéras, 1970a; Pollock, 1986b; Tan, 2000). Single infants are the rule, and the interbirth interval is typically one year. Infants are first carried from the mother’s mouth, then on her back a few weeks after birth, and eventually she is able to “park” them for short periods of time while she forages (Tan, 2000).

Geographic range

The northern bamboo lemur occurs in a number of discontinuous pockets in western and northern Madagascar. It is known from the forests of Ankarana and Analamerana in the far north, the Sambirano region, the Ampasindava Peninsula, and the Sahamalaza region (north of the Andranomalaza River) in the northwest; the Tsiombikibo, Baie de Baly, Tsingy de Namoroka and Bongolava regions in the central-west between the Mahavavy and Tsiribihina Rivers; Masoala, Maroansetra and Ile Roger (Aye-aye Island) in the northeast; and as far south as Zahamena and Marovohangy near Lake Alaotra (Tattersall, 1982; Hawkins et al., 1990, 1998; Rakotoarison et al., 1993; Curtis et al., 1995; Rabarivola et al., 2007; Y. Rumpler, pers. comm.; C. Schwitzer, pers. obs.). Information on which forests may or may not be contiguous remains to be determined.

Conservation status

The most recent IUCN Red List assessment (2008) classified H. occidentalis as Vulnerable (VU). The principal threat is habitat loss due to regular burning to create pasture for livestock, charcoal production, and mining. Recent studies in the Makira Forest documented the hunting of this species, but did not determine whether current levels were sustainable (Golden, 2005). Its presence is reported in eight national parks (Ankarana, Baie de Baly, Mananara-Nord, Marojejy, Masoala, Sahamalaza-Iles Radama, Tsingy de Namoroka, and Zahamena), two strict nature reserves (Tsaratanana and Zahamena), and eight special reserves (Ambatovaky, Analamerana, Anjanaharibe-Sud, Bemarivo, Kasijy, Maningoza, Manongarivo, and Marotandrano) (Nicoll and Langrand, 1989; Schmid and Smolker, 1998; Hawkins et al., 1998; Thalmann et al., 1999; Randrianarisoa et al., 2001a, 2001b; C. P. Groves, pers. comm.; Rabarivola et al., 2007; C. Schwitzer, pers. obs.). Recent surveys, however, did not encounter any animals in Analamerana or Ankarana, just in a single patch of unprotected forest in the corridor that connects these reserves (Banks, 2005). The Hapalemur at Tsingy de Bemaraha National Park, previously thought to be this species, is now thought to be H. g. ranomafanensis (see Rabarivola et al. 2007). As of 2010, there was a small, non-breeding population of around 18 in various European zoos (C. Schwitzer, pers. obs.; I. J. Porton, pers. comm.).

Where to see it

This lemur is not easily seen and is apparently nowhere common. Garbutt (2007) and R. A. Mittermeier (pers. obs.) have seen H. occidentalis in forests along the Sambirano River Valley near the village of Benavony, southeast of Ambanja, and it has also been seen on Nosy Faly, peninsula approximately 30 km northeast of Ambanja. There are simple hotel accommodations in Ambanja and better accommodations at Ankify nearby. Sightings are also possible around Lac Bemamba and in the Manongarivo Special Reserve, but one might have to spend several days to ensure success. On the eastern side of its range, it can also be seen in the national parks of Marojejy and Masoala.

Photographs

You are here

Hapalemur occidentalis Rumpler, 1975

Species

Main menu

Primate watching

Configuration

You are here

Hapalemur occidentalis Rumpler, 1975

Species

Main menu

Primate watching

Search form

Configuration