As a result of severe ecological and human pressures, the lemur is classified as Critically Endangered (CR) by the IUCN Red List.

[1] The genus Lepilemur was initially thought to comprise only 2 species: L. mustelinus and L. ruficaudatus, with the latter subdivided into 2 subspecies.

[13] The lemurs often adopt an upright vertical posture, using enlarged and fleshy digital pads on their hands and feet to cling tightly to tree branches.

[14] The contact rejection call is a series of resonant hisses followed by a two-phase vocalisation, most commonly heard when two individuals approach each other in the wild.

[19] The northern sportive lemur is a foliovorous species, though they will also eat fruits and flowers to supplement their diet.

Similarly to the other sportive lemurs, L. septentrionalis is caecotrophic, consuming its own faeces to digest food for a second time.

[15] The species have large bacteria-filled ceca, which helps them to digest plant matter such as cellulose and break it down into sugars and starches.

[12] This combination of threats has severely reduced the population of the lemurs to only a few hundred individuals, as estimated by the IUCN Red List.

[20] The known habitat range of the lemurs does not overlap with any protected areas, and although the Andrahona Forest is considered sacred in Madagascar, it shows signs of human incursion.