Brown lemurs, like all true lemurs, have binocular vision and long furry tails. They have a scent gland located at their wrist that is used in olfactory communication. This species is sexually dichromatic - its males and females have different fur patterns.
All the members of this species fall within the broad size range of 2 to 4 kg. This is about the size of a housecat. Each subspecies has its own unique markings on its fur.
Red-fronted brown lemurs have an average weight of about 2.7 kg and their average body length is 40 cm. The tail is about 55 cm long. The males are gray to gray-brown and have a reddish crown. The females are reddish-brown. All red-fronted brown lemurs have pale patches over their eyes.
Common brown lemurs, weigh around 2.6 kg. Their body length is 50 cm, as is their tail length. Both males and females are brown to dark-gray with light beards and dark faces.
White-fronted lemurs have a body weight of 2.3 kg, and body length of 40 cm, and a tail length of greater than 50 cm. Generally, this subspecies is dark brown with a lighter underside. Males have a white or cream colored head, ears and beard.
Collared lemurs are around 2.6 kg, with a body length of 50 cm and a tail length of 50 cm as well. Males are brownish-gray with a dark stripe down the back, a dark tail and tail tip, and a lighter underside. Females have a reddish to brown coat and a gray face. Both sexes have a distinct beard that is reddish-brown in females and cream to reddish-brown in males.
Sanford's lemurs weigh around 2.3 kg and have a body length of 40 cm with a tail length of 50+ cm. They can be distinguished from the other subspecies by their fur. Both sexes are dark brown with a lighter underside. Noses, snouts and the area between the eyes are black, and a dark "T" that connects the eyes and nose dominates the head. Males have white-reddish ear tufts and thick beards, providing them the illusion of a 'ragged mane' around their faces.
Range mass: 2 to 4 kg.
Range length: 40 to 50 cm.
Sexual Dimorphism: sexes colored or patterned differently
Average basal metabolic rate: 4.239 W.