Presenting the buttocks is a sign of submission not only for the mandrill, but also for many Old World monkeys. Spreading the arms, displaying a lowered head and revealing the teeth in a yawning gesture are threats towards an opponent. The slight revealing of the teeth, which may be accompanied, by teeth chattering is an indication of friendliness, a greeting, and an expression of well being. This blush serves as a threat display to rival males. The mandrill can live up to 46 years in captivity.
Predators are leopards and man.
The numbers of mandrills in Africa have been dropping rapidly, due to hunting and deforestation. Univ. of Michigan. Museum of Zoology. Central Florida Zoo. Walker's Mammals of the World.