The Zoo’s hamadryas baboon group is made up of 12 females and eight males, ranging in ages from 23 years to 3 months. Hamadryas baboons are unique among baboon species in that their social structure is strictly patriarchal—the males are in charge and the females are subordinate to the males. These baboons have a large body, a strong build and a dog-like muzzle. Both males and females have brown or light gray fur. Females are smaller and have hairless brown faces, while the male baboon has a distinctive mane of long silvery hair and a bright pink face and backside.