Brown Lemurs were once considered as a single species with 7 sub species; but as they have been studied further, their degree of physical divergence is such that they are now classified as 8 separate species within the 12 species True Lemur family (Eulemur). This family also includes Black Lemurs, which we observe in forest on Nosy Be and various smaller neighbouring islands; and Crowned Lemurs which we find in the tsingy of Ankarana and the Amber Mountain National Park. 

Here is the list: 

Common Brown Lemur (Eulemur fulvus)
Sanford's Brown Lemur (Eulemur sanfordi)
Crowned Lemur (Eulemur coronatus)
Black Lemur (Eulemur macaco)
Black-eyed Black Lemur (Eulemur flavifrons)
White-headed Lemur (Eulemur albifrons)
Grey-headed Lemur (Eulemur cinereiceps)
Red Lemur (Eulemur rufus)
Red-fronted Lemur (Eulemur rufifrons)
Red-bellied Lemur (Eulemur rubriventer)
Collared Brown Lemur (Eulemur collaris)
Mongoose Lemur (Eulemur mongoz)

True Lemurs are the most numerous and widespread lemur, existing in all forest types, from the tropical rainforests of the east, to the tropical dry and spiny forests of the west. This reflects their diet, which consists primarily of leaves, fruit, sap and flowers. In captivity, they have also been observed eating insects. 

Of the lemurs you might see in Madagascar, Brown Lemurs are about average size wise, with adults weighing in between 2 and 4 kg (4 - 9 lbs). Their body length ranges from 30 to 50 cm ( 12 to 20 inches), with tails longer than this. They are predominantly active during the day, forming energetic and often leaping groups of up to 30 individuals. It is usually the crashing of leaves which gives them away, leading to the exciting process of creeping closer through the forest in pursuit of a view. 

One of the easiest places to see Common Brown Lemurs is on the tropical island gem of Nosy Tanikely.  This is off Nosy Be, where a troop was introduced and has since flourished. This is not their native zone, which is pretty much the northern half of Eastern Madagascar and the northern quarter of Western Madagascar; excluding the far north where Sanford's Brown Lemur takes over. 

Visually, brown lemurs share a dense compact woolly fur. If there was ever a lemur you wanted to hug, these would be the cuddliest! 

Whilst some species of lemur have proven unable to survive in captivity, brown lemurs do well and breed successfully. Naturally,  they give birth just before the rainy season, following 125 days of gestation. They usually give birth to two offspring,  which wean for 5 months and reach maturity at 18 months. Their lifespan is around 18 years, although those in captivity can live longer. 

Brown Lemurs are fairly resilient to forest disturbance and will sometimes step beyond the forest to raid planted tree crops. They are not able to survive significant forest loss, however, so deforestation leads to a proportionate reduction in population. Their conservation status varies from Near Threatened for the likes of the Common Brown Lemur, to Endangered for Sanford's Brown Lemur and the White-fronted Brown Lemur we see on Nosy Mangabe, the Masoala Peninsula and Marojejy.