A total of 23 species of mammals were recorded from the sanctuary (Balakrishnan et.al, 1998).
All the five species of primates are present in the area. Arboreal mammals other than primates seen in Aralam are the Malabar giant squirrel (Ratufa indica) and the Flying squirrel (Petaurista petaurista).
The Coorg race, Ratufa indica bengalensis was also reported from the sanctuary. Other mammals in the area include the Indian Elephant, Sambar deer, Barking deer, Mouse deer, Wild boar and gaur.
The Tiger and Leopard are the predators in the area.