Microcebus sambiranensis is one of the smallest of the mouse lemurs, with a head-body length of 11–12 cm, a tail length of 13.5–14.5 cm, a total length of 25–27 cm, and a body weight of just 38–50 g (Rasoloarison et al., 2000; Andriantompohavana et al., 2006). The dorsal coat is a bright reddish-cinnamon with a poorly defined, amber midline stripe that extends from just beyond the shoulders to the end of the tail. The ventral coat is a duller whitish-beige. There is a pale patch between the eyes, which are surrounded by dark orbital rings. The crown and ears are amber.
The Sambirano mouse lemur is named for the Sambirano region of northern Madagascar, where elements of the country’s humid eastern and dry western forests meet. It can also be found in disturbed habitats and in forests bordering agricultural sites. No systematic studies of the ecology or behavior of this species have been conducted to date, and there are no estimates of population size or density.
Northwestern Madagascar. This species is presently known only from the Manongarivo Special Reserve (Rasoloarison et al., 2000; Goodman and Soarimalala, 2002), north of the Andranomalaza River and south of the Sambirano River (Louis et al., 2006a). It is possibly also found in isolated populations on the Ampasindava Peninsula and in the Tsaratanana Massif (Randrianambinina et al., 2003c; Louis et al., 2008). Prior to the description of this species, the mouse lemur of Manongarivo was thought to be M. rufus (see Tattersall, 1982).
Microcebus sambiranensis is Endangered (EN) according to the IUCN Red List assessment of 2008. The principal threat is habitat loss due to slash-and-burn agriculture, firewood collection, and charcoal production. It is protected in the Manongarivo Special Reserve.
As of 2009, this species was not being kept in captivity (ISIS, 2009).
So far, the only place to see M. sambiranensis in the wild is in the Manongarivo Special Reserve. The reserve can be reached by four-wheel-drive vehicle from Ambanja, which is about 60 km to the north. It is probably best to contact an Antsiranana- or Nosy Be-based tour operator to arrange such a trip, and it is important to get permission from Madagascar National Parks in advance to enter this reserve. It is not easy to reach. There are several hotels in Ambanja and at least two very good ones in nearby Ankify.