Baboon
Baboons are primates comprising the genus Papio, one of the 23 genera of Old World monkeys. There are five species of baboons, commonly known as hamadryas baboon, Guinea baboon, olive baboon, yellow baboon and chacma baboon. Each species is native to one of five areas of Africa and the hamadryas baboon is also native to part of the Arabian Peninsula. Baboons are among the largest non-hominoid primates and have existed for at least two million years.
Baboons vary in size and weight depending on the species. The smallest, the Kinda Baboon, is in length and weighs only, while the largest, the chacma baboon, is up to in length and weighs. All baboons have long, dog-like muzzles, heavy, powerful jaws with sharp canine teeth, close-set eyes, thick fur except on their muzzles, short tails, and nerveless, hairless pads of skin on their protruding buttocks called ischial callosities that provide for sitting comfort. Male hamadryas baboons have large white manes. Baboons exhibit sexual dimorphism in size, colour and/or canine teeth development.
Baboons have diurnality and are terrestrial, but sleep in trees, or on high cliffs or rocks at night, away from predators. They are found in open savannahs and woodlands across Africa. They are omnivorous: common sources of food are grasses, seeds, roots, leaves, bark, various fruits, insects, fish, shellfish, rodents, birds, vervet monkeys and small antelopes. Their principal predators are Nile crocodiles, leopards, lions and hyenas. Most baboons live in hierarchical troops containing harems. Baboons can determine from vocal exchanges what the dominance relations are between individuals.
In general, each male can mate with any female; the mating order among the males depends partly on their social rank. Females typically give birth after a six-month gestation, usually to one infant. The females tend to be the primary caretaker of the young, although several females may share the duties for all of their offspring. Offspring are weaned after about a year. They reach sexual maturity around five to eight years. Males leave their birth group, usually before they reach sexual maturity, whereas most females stay in the same group for their lives. Baboons in captivity live up to 45 years, while in the wild they average between 20 to 30 years.
Taxonomy
Five species of Papio are commonly recognized, although there is some disagreement about whether they are really full species or subspecies. They are P. ursinus, P. papio, P. hamadryas, P. anubis and P. cynocephalus.The five species of baboons in the genus Papio are:
- Hamadryas baboon, Papio hamadryas
- Guinea baboon, Papio papio
- Olive baboon, Papio anubis
- Yellow baboon, Papio cynocephalus
- * Central yellow baboon, Papio cynocephalus cynocephalus
- * Ibean baboon, Papio cynocephalus ibeanus
- * Kinda baboon, Papio cynocephalus kindae
- Chacma baboon, Papio ursinus
- * Cape chacma, Papio ursinus ursinus
- * Gray-footed chacma, Papio ursinus griseipes
- * Ruacana chacma, Papio ursinus raucana
| Image | Scientific name | Common Name | Distribution |
| Papio hamadryas | Hamadryas baboon | From the Red Sea in Eritrea to Ethiopia, Djibouti, Somalia, southwestern Arabia, in both Yemen and Saudi Arabia | |
| Papio papio | Guinea baboon | Guinea, Senegal, Gambia, Southern Mauritania and Western Mali | |
| Papio anubis | Olive baboon | Equatorial Africa | |
| Papio cynocephalus | Yellow baboon | From Kenya and Tanzania to Zimbabwe and Botswana. | |
| Papio ursinus | Chacma baboon | South Africa North to Angola, Zambia, and Mozambique |
Many authors distinguish P. hamadryas as a full species, but regard all the others as subspecies of P. cynocephalus and refer to them collectively as "savanna baboons". This may not be helpful: it is based on the argument that the hamadryas baboon is behaviorally and physically distinct from other baboon species, and that this reflects a separate evolutionary history. However, recent morphological and genetic studies of Papio show the hamadryas baboon to be more closely related to the northern baboon species than to the southern species.
The traditional five-form classification probably under-represents the variation within Papio. Some commentators argue that at least two more forms should be recognized, including the tiny Kinda baboon from Zambia, DR Congo, and Angola, and the gray-footed baboon found in Zambia, Botswana, Zimbabwe, Mozambique, and northern South Africa. However, current knowledge of the morphological, genetic, and behavioral diversity within Papio is too poor to make any final, comprehensive judgment on this matter.
Phylogeny
In 2015 researchers found the oldest baboon fossil dating 2 million years ago.Characteristics
All baboons have long, dog-like muzzles, heavy, powerful jaws with sharp canine teeth, close-set eyes, thick fur except on their muzzles, short tails, and rough spots on their protruding buttocks, called ischial callosities. These calluses are nerveless, hairless pads of skin that provide for the sitting comfort of the baboon.All baboon species exhibit pronounced sexual dimorphism, usually in size, but also sometimes in colour or canine development. Males of the hamadryas baboon species also have large white manes.
Behavior and ecology
Baboons are able to acquire orthographic processing skills, which form part of the ability to read.Habitat and prey
Baboons are terrestrial and are found in open savannah, open woodland and hills across Africa. Their diets are omnivorous: they eat grasses, roots, seeds, leaves, fruits, insects, fish, shellfish, rodents, birds, vervet monkeys, and small antelopes. They are foragers and are active at irregular times throughout the day and night. They often raid human dwellings, and in South Africa, they have been known to prey on sheep, goats and poultry.Predators
Their principal predators are Nile crocodiles, lions, spotted and striped hyenas, leopards, and cheetahs. They are considered a difficult prey for the leopard, though, which is mostly a threat to young baboons. Large males will often confront them by flashing their eyelids, showing their teeth by yawning, making gestures, and chasing after the intruder/predator. Although they are not a prey species, baboons have been killed by the black mamba snake. This usually occurs when a baboon accidentally rouses the snake.Social systems
The collective noun for baboons is "troop". Most baboons live in hierarchical troops. Group sizes are typically around 50 animals, but can vary between 5 and 250, depending on species, location and time of year. The structure within the troop varies considerably between hamadryas baboons and the remaining species, sometimes collectively referred to as savanna baboons. The hamadryas baboons often appear in very large groups composed of many smaller harems, to which females from elsewhere in the troop are recruited while they are still too young to breed. Other baboon species have a more promiscuous structure with a strict dominance hierarchy based on the matriline. The hamadryas baboon group will typically include a younger male, but he will not attempt to mate with the females unless the older male is removed. In the harems of the hamadryas baboons, the males jealously guard their females, to the point of grabbing and biting the females when they wander too far away. Despite this, some males will raid harems for females. Such situations often cause aggressive fights between the males. Visual threats usually accompany these aggressive fights. These include a quick flashing of the eyelids accompanied by a yawn to show off the teeth. Some males succeed in taking a female from another's harem, called a "takeover". In several species, infant baboons are taken by the males as hostages, or used as shields during fights.Baboons can determine from vocal exchanges what the dominance relations are between individuals. When a confrontation occurs between different families or where a lower-ranking baboon takes the offensive, baboons show more interest in this exchange than those between members of the same family or when a higher-ranking baboon takes the offensive. This is because confrontations between different families or rank challenges can have a wider impact on the whole troop than an internal conflict in a family or a baboon reinforcing its dominance.
Baboon social dynamics can also vary; Robert Sapolsky reported on a troop, known as the Forest Troop, during the 1980s, which experienced significantly less aggressive social dynamics after its most aggressive males died off during a tuberculosis outbreak, leaving a skewed gender ration of majority females and a minority of low-aggression males. This relatively low-aggression culture persisted into the 1990s and extended to new males coming into the troop, though Sapolsky observed that while unique, the troop was a not an "unrecognizably different utopia"; there was still a dominance hierarchy and aggressive intrasexual competition amongst males. Furthermore, no new behaviours were created amongst the baboons, rather the difference was the frequency and context of existing baboon behaviour.
Mating
Baboon mating behavior varies greatly depending on the social structure of the troop. In the mixed groups of savanna baboons, each male can mate with any female. The mating order among the males depends partially on their social ranking, and fights between males are not unusual. There are, however, more subtle possibilities; in mixed groups, males sometimes try to win the friendship of females. To garner this friendship, they may help groom the female, help care for her young, or supply her with food. The probability is high that those young are their offspring. Some females clearly prefer such friendly males as mates. However, males will also take infants during fights to protect themselves from harm. A female initiates mating by presenting her swollen rump to the male's face.Birth, rearing young, and life expectancy
Females typically give birth after a six-month gestation, usually to a single infant; twin baboons are rare and often do not survive. The young baboon weighs approximately 400 g and has a black epidermis when born.The females tend to be the primary caretaker of the young, although several females will share the duties for all of their offspring.
After about one year, the young animals are weaned. They reach sexual maturity in five to eight years. Baboon males leave their birth group, usually before they reach sexual maturity, whereas females are philopatric and stay in the same group their whole lives.
Baboons in captivity have been known to live up to 45 years, while in the wild their life expectancy is between 20 to 30 years.