Baboons can work out who outranks whom just by eavesdropping
Among the biggest monkeys alive, baboons live in troops of up to 250 animals with strict pecking orders. Listening to vocal exchanges is enough for them to judge dominance between other individuals. Leopards find grown baboons tough prey, and large males stare them down by flashing eyelids and baring huge canines.
Baboons make up the genus Papio, one of 23 genera of Old World monkeys. Six species are recognised: hamadryas, Guinea, olive, yellow, Kinda and chacma, each native to its own region of Africa, with the hamadryas also reaching the Arabian Peninsula. Whether all six are full species is disputed. The Kinda earned its place only after phylogenetic studies; many authors treat the hamadryas as distinct and lump the rest together as savanna baboons. The oldest baboon fossil, found in 2015, is about 2 million years old.
Size varies a lot. The Kinda measures about 50 centimetres and weighs roughly 14 kilograms, while the chacma reaches 120 centimetres and 40 kilograms. All have long dog-like muzzles, powerful jaws, close-set eyes, short tails and hairless, nerveless pads on the rump called ischial callosities, which make sitting comfortable. Males are much bigger than females, carry far larger canines for intimidation, and in hamadryas baboons sport a white mane.
Baboons forage on the ground by day across savanna, woodland and hills, then retreat to trees or cliffs to sleep safely. They are opportunists that eat almost anything, from grasses, roots and bark to insects, fish, rodents and birds. Apart from people, their chief enemies are leopards, lions and hyenas, along with Nile crocodiles.
Troops typically hold around 50 animals, though the range runs from 5 to 250, and hamadryas groups are organised quite differently from other species. Mating order among males depends partly on rank. After about six months of pregnancy a female usually bears a single infant, and several females may share childcare. Young are weaned at about a year and mature between five and eight. Males leave their birth troop, while most females stay for life. Wild baboons average 20 to 30 years; captive ones can reach 45.
Source: Baboon
