Like other brown lemurs, this species is cathemeral (active during the day and the night), lives in social groups, primarily eats fruit, exhibits sexual dichromatism, and does not demonstrate female dominance.

The species is listed as Endangered by the International Union for Conservation of Nature (IUCN) and is threatened primarily by habitat loss.

The collared brown lemur can be found in the littoral forests of Mandena Conservation Zone, Sainte Luce Reserve, and Andohahela National Park.

[5][6] Research has suggested that metabolic dietary-related needs are the leading factor behind this behavior, although the specific hours of this activity pattern can shift based on lunar luminosity and seasonal changes in the photoperiod (day length).

[11] Previous studies had ruled out effects of predators on the expression of this trait, and instead pointed to fruit availability and fiber intake as more important factors.

[5][12] Brown lemurs at Berenty (hybrid E. fulvus x collaris) [13] show linear hierarchy, adult female dominance, and the presence of conciliatory behavior after aggressions.

[5] However, populations of the collared brown lemur have been successfully sustained in captivity and continue to provide a safeguard against their extinction.