The total number of individuals is estimated to be around 1000.[1] Some experts believe this to be an overestimate, as recent studies have shown that the average area inhabited by the black lion tamarin is closer to 106 hectares (260 acres) than the previously estimated 66 hectares (160 acres).[5] They are usually found in groups of 4 to 9, living in the secondary and primary forests along the circumference of its home range.