The adult male displays vivid coloration on his face and rump in hues of blue, red, and purple. The coloration helps mandrills to identify one another when they are foraging. The male also has long, powerful canine teeth. Female and young mandrills are much less colorful than the adult male. Their faces are grayish black and lack any bright shades of color.
Females are half the size and weight of males.
Young mandrills of both sexes have the same coloration as adult females. Males attain their full coloration when they are sexually mature. Click here for pictures of the Mandrill.