Lepilemur tymerlachsonorum is a small to medium-sized species with a head-body length of 23 cm, a tail length of 25 cm, a total length of 48 cm, and a body weight of roughly 880 g (Louis et al., 2006b). The dorsum is light brownish-gray, with the upper half of the back a light reddish-brown and the underside a light grayish-white. The anterior aspects of the thighs and edges of the extremities also have a light reddish-brown diffuse color. A dark brown to black midline stripe is present from the head to the lower half of the back, and the tail is a uniform light reddish-gray to brown. The face is gray and mask-like (Louis et al., 2006b). The taxonomy of the sportive lemurs in this part of Madagascar still remains to be clarified, especially the relationship between this species, Lepilemur dorsalis, and Lepilemur mittermeieri.
This species inhabits tropical moist lowland forests that are subject to a dry season each year. It appears to be more common in secondary forests. In dense primary forest it favors tree holes for daytime sleeping, but will seek out vegetation tangles in more open deciduous forest (Petter and Petter, 1971; Raxworthy and Rakotondraparany, 1988). It feeds on leaves, fruit and bark. Births occur from August through November, mothers typically producing a single young. Predators include the Madagascar Harrier-hawk (Polyboroides radiatus) and the Madagascar Buzzard (Buteo brachypterus).
Northwestern Madagascar. The Nosy Be sportive lemur, Lepilemur tymerlachsonorum, appears to be confined to the Lokobe region on the island of Nosy Be (Louis et al., 2006b). This may or may not be the species that occurs on the island of Nosy Komba as well, but sportive lemurs have not been observed there in recent years. Zinner et al. (2007) found that some specimens from the mainland were identical in mtDNA to the type of L. tymerlachsonorum, so there is some question as to whether or not this species is also on the mainland. The sportive lemurs found on Nosy Be were previously considered to be Lepilemur dorsalis.
We do not know enough to determine the conservation status of L. tymerlachsonorum and the latest IUCN Red List assessment (2008) classified it as Data Deficient (DD). It is known to occur in one protected area, the Lokobe Strict Nature Reserve on Nosy Be (Louis et al., 2006b). As of 2010, this species was not being kept in captivity (I. J. Porton, pers. comm.).
This species can easily be seen in the Lokobe Strict Nature Reserve on the island of Nosy Be. Several tours visit forests around this protected area, and local guides usually know the whereabouts of their daytime sleeping sites, which are only a few meters above the ground and where the animal is quite easy to observe. A particularly good site is Ampasipohy, where there are two comfortable beachfront lodges, with Lepilemur to be found in forest right behind them.