The Indris
The Indris (Indri indri) is the most arboreal of all the lemurs and hardly ever comes down to the ground. It is the biggest of all living lemurs with a head and body nearly a metre long, and its legs are even longer in proportion than those of a Sifaka, the big toes are widely separated from the rest and about twice the length, so that each foot resembles a huge calliper with which the animal can grasp thick trunks. Indris also use scent in marking the trees, though to a much lesser extent than the lemurs. Instead territories are established using their voices. Every morning and evening, a family fills its patch of forest with an unearthly wailing chorus.
