Baboon
2008/9 Schools Wikipedia Selection. Related subjects: Mammals
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 Olive Baboon (Papio anubis)
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| Simia hamadryas Linnaeus, 1758 |
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Papio hamadryas |
The five baboon species are some of the largest non- hominid members of the primate order; only the Mandrill and the Drill are larger. In modern scientific use, only members of the genus Papio are called baboons, but previously the closely related Gelada (genus Theropithecus) and two species of Mandrill and Drill (genus Mandrillus) were grouped in the same genus, and these Old World monkeys are still often referred to as baboons in everyday speech. The word "baboon" comes from "babouin", the name given to them by the French naturalist Buffon. The baboon held several positions in Egyptian mythology. The baboon god Baba, was worshipped in Pre-Dynastic times; alternatively, this may be the origin of the animal's name. Papio belongs to family Cercopithecidae, in subfamily Cercopithecinae.
Physiology
All baboons have long dog-like muzzles (cynocephalus, "dog-head"), close-set eyes, heavy powerful jaws, thick fur except on their muzzle, a short tail and rough spots on their protruding hindquarters, called ischial callosities. These callouses are nerveless, hairless pads of skin which are present to provide for the sitting comfort of the baboon (and other Old World monkeys). Males of the Hamadryas Baboon species also have a large white mane.
There is considerable variation in size and weight depending on species, the Guinea Baboon is 50 cm (20 inches) and weighs only 14 kg (30 lb) while the biggest Chacma Baboon can be 120 cm (47 inches) and weigh 40 kg (90 lb).
In all baboon species there is pronounced sexual dimorphism, usually in size but also sometimes in colour or canine development.
Baboons are terrestrial (ground dwelling) and are found in open savannah, open woodland and hills across Africa. Their diet is omnivorous, but is usually vegetarian. They are foragers and are active at irregular times throughout the day and night. They can raid human dwellings and in South Africa they have been known to prey on sheep and goats.
Their principal predators are man and the leopard, although they are tough prey for a leopard and large males will often confront them by flashing their eyelids, showing their teeth by yawning, making gestures, and chasing after the intruder/predator.
Baboons in captivity have been known to live up to 45 years, while in the wild their life expectancy is about 30 years.
Society
Most baboons live in hierarchical troops. Group sizes vary between 5 to 250 animals (often about 50 or so), depending on specific circumstances, especially species 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 Baboon has very large groups comprised of many smaller harems (one male with four or so females), to which females from elsewhere in the troop are recruited while still too young to breed. The other baboon species have a more promiscuous structure with a strict dominance hierarchy based on the female 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.
Another baboon society in Africa interacts with the Masai by stealing their goats for meat and waiting for Masai to dig in the dry river beds for water. After the Masai leave the water hole, the baboons sneak in to drink whatever water is left.
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 the exchange than exchanges 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.
The collective noun for baboons is commonly troop or congress, although flange is also becoming common. This unusual term originates from a Not the Nine O'Clock News comedy sketch entitled "Gerald The Intelligent Gorilla" where it was used for comic effect.
Mating and birth
Baboon mating behaviour 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; 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 them with food. Some females clearly prefer such friendly males as mates. However, males will also take infants during fights in order to protect themselves from harm.
A female initiates mating by presenting her swollen rump to the male. But 'presenting' can also be used as a submissive gesture and is observed in males as well.
In the harems of the Hamadryas Baboon, 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. In such situations it often comes to aggressive fights by the males. Visual threats are usually accompanied by these aggressive fights. This would 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. This is called a 'takeover'. In many species, infant baboons are taken by the males as hostages during fights.
Females typically give birth every other year, usually to a single infant, after a six month gestation. The young baboon weighs approximately one kilogram and is colored black when they are born. The females tend to be the primary caretaker of the young, although several females will share the duties for all of their offspring.
In mixed groups males sometimes help in caring for the young of the females they are friendly with, for instance they gather food for them and play with them. The probability is high that those young are 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 life.
Cultural importance
The Hamadryas Baboon was a sacred animal to the ancient Egyptians as the attendant of Thoth, and so, is also called the Sacred Baboon. The English word Baboon is thought to derive from the name of the Egyptian baboon-god Hapi.
Classification and 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 ( Chacma Baboon, found in southern Africa), P. papio (Western, Red, or Guinea Baboon, found in the far west of Africa), P. hamadryas ( Hamadryas Baboon, found in the Horn of Africa and south-western Arabia), P. anubis ( Olive Baboon, found in the north-central African savanna) and P. cynocephalus ( Yellow Baboon, found in south-central and eastern Africa). 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 (the Guinea and Olive Baboons) than to the southern species (the Yellow and Chacma Baboons).
The traditional 5-form classification probably under-represents the variation within Papio. Some commentators would argue that at least two more forms should be recognized, including the very tiny Kinda Baboon (P. cynocephalus kindae) from Zambia, the DRC, and Angola, and the Gray-footed Baboon (P. ursinus griseipes) found in Zambia, Botswana, Zimbabwe, Mozambique, and northern South Africa. However, current knowledge of the morphological, genetic, and behavioural diversity within Papio is too poor to make any final, comprehensive judgments on baboon taxonomy.
Species list
There are 6 different species of baboons:
- Genus Papio
- Hamadryas Baboon, Papio hamadryas
- Guinea Baboon, Papio papio
- Olive Baboon, Papio anubis
- Yellow Baboon, Papio cynocephalus
- Chacma Baboon, Papio ursinus
- Theropithecus
- Gelada Baboon. Theropithecus gelada