Where are Drills found?

Drill monkeys are one of the most endangered primate species in the world. The drill is found in a very small geographic area with a high human density (from the Cross River in Nigeria to the Sanaga River in Cameroon - see Tengwood.org's 'Rivers and Wildlife' article).  On this map, one can see that the drill has a much smaller range than the mandrill.  Drills are classified by the IUCN as endangered.  With their larger range and population size, in an area of Central Africa that is less populated by humans, mandrills are classified as threatened.