Lepilemur sahamalazensis is a small sportive lemur with a head-body length of 19–24 cm, a tail length of about 24 cm, a total length of 44–48 cm, and a body weight of roughly 700 g (Andriaholinirina et al., 2006; Louis et al., 2006b). The pelage coloration is variable, possibly depending on the age of the individual. The upper body is predominantly reddish- brown with gray or creamy underparts. It has a reddish-brown to deep brown tail. There is a dark, diffuse dorsal stripe running from the top of the head to the lower back. The face is essentially gray, with the forehead and areas around the ears reddish-brown, sometimes with darker, diffuse patches (Andriaholinirina et al., 2006).
This species has recently been studied in the Ankarafa Forest on the Sahamalaza Peninsula (Ruperti, 2007). Although these animals are essentially nocturnal, at least 40% of the time in their daytime sleeping sites is spent either resting vigilantly or grooming. Sahamalaza sportive lemurs seem to rest less in disturbed forest areas with a lower density of large trees and vegetation tangles. Although tree holes are usually the favored sleeping sites of sportive lemurs, individuals of this species observed in tree holes were found to be significantly more active during the day than those that had been resting in vegetation tangles (Ruperti, 2007).
This species is evidently restricted to the Sahamalaza Peninsula and the adjacent mainland of coastal northwestern Madagascar. The biogeography of this area and the distribution pattern of the sympatric Eulemur flavifrons make it likely that the boundaries of the range of L. sahamalazensis are the Andranomalaza River in the north and the Maevarano River in the south. Field studies to determine the full extent of the species’ distribution and that of the neighboring Lepilemur mittermeieri are under way (C. Schwitzer, pers. comm.).
There was not enough information to determine the conservation status of L. sahamalazensis in the latest IUCN Red List assessment (2008), so it was classified as Data Deficient (DD). However, since then the species has been provisionally assessed as Critically Endangered, with a formal proposal submitted to the IUCN. It was also placed on the list of the world’s 25 Most Endangered Primates 2006–2008 (Olivieiri et al., 2007b). It occurs in the southern part of the newly-created Sahamalaza-Iles Radama National Park, where it seems to be abundant in primary and older secondary forest. However, it probably has a very limited distribution, and the forest that it lives in is rapidly decreasing and extremely fragmented. Hunting pressure is high. Indeed, the threats that it faces are similar to those of the sympatric blue-eyed black lemur (Eulemur flavifrons), which is Critically Endangered (CR). A maximum of five L. sahamalazensis were found to inhabit one hectare of forest, with an average of 2.8 per hectare. Total population size was estimated to be no more than 3,000 individuals within the boundaries of the national park (Ruperti, 2007). Population densities tend to be higher in areas with more large trees, a more closed canopy, and a greater abundance of food plants, suitable sleeping holes and vegetation tangles. The presence of livestock reduces population numbers. As of 2010, this species was not being kept in captivity (I. J. Porton, pers. comm.).
The best place to see this species is in remaining forest patches on the Sahamalaza Peninsula. For example, the Ankarafa Forest can be reached by a one-hour boat trip from Analalava to the small village of Marovato, and from there a hike of about two hours inland. The Sahamalaza Peninsula can also be reached by pirogue from Maromandia. Sahamalaza sportive lemurs can readily be found when they are active during the night but also during the day when they are in their tree holes.