Alien  Earthlings
Mandrill

Mandrills live in small social units, but often join up with other small groups to form larger ones called hordes. 

One of the largest groups documented numbered over 1,200 mandrills! Mandrill hordes are noisy. They communicate with deep grunts and high-pitched screams while they forage and travel. Male mandrills do not reach full adult maturity until they are about nine years old. This is a challenging time in their life. They must find their own food and fight other males to assert themselves as they work their way up the ranks. During this time, their bright rump and facial colors appear. The more testosterone they develop, the more vibrant his colors and the more attractive he becomes to the females. 

The females choose which males they want to socialize and breed with. Only the most colorful and social males sire the majority of the offspring. Those colors fade on a male that loses status.