Pan troglodytes
The common chimpanzee (Pan troglodytes) or simply chimpanzee, also called jocó b>, is a species of hominid primate native to tropical Africa. Chimpanzees —along with bonobos— are the closest living relatives to humans; their evolutionary branch diverged from the human branch approximately seven million years ago and they share 98% of their DNA with them, which has led Jared Diamond to use the term "the third chimpanzee" to refer to our own species. Males can weigh up to 80kg in captivity and measure up to 1.7m. It is characterized by its advanced intelligence, often compared to that of humans. For example, young chimpanzees have been observed to make "dolls" and other toys with sticks and sticks.
It is currently in danger of extinction due to deforestation of its natural habitat.
Geographic distribution
We can find chimpanzees in the tropical rainforests and humid savannahs of central and western Africa. They used to inhabit most of this region, but their habitat has been drastically reduced in recent years due to deforestation.
Morphology
In the erect position, adults are between 1 m and 1.7 m tall. The males in the wild weigh between 34 and 70 kg, while the females have between 26 and 50 kg. In captivity, males can weigh up to 80 kg and females 68 kg. Apparently P. t. schweinfurthii weighs less than P. t. verus, which is smaller than P. t. troglodytes. Chimpanzee arms are much longer than their legs. Their arms span is about 1.5 times the individual's height. Long arms allow these primates to swing from branch to branch; this modality of locomotion is called brachiation. They also have long fingers and hands, but the thumb is short. This allows them to hold onto branches without interfering with the mobility of their thumbs.
Chimpanzees have a cranial capacity of 320 to 480 cubic centimeters, far less than that of modern humans (Homo sapiens), who have an average of 1,400 cubic centimeters.
Their bodies are covered in thick, dark brown fur, except for their faces, fingers, palms, and soles. Both his thumbs and big toe are opposable, allowing for a precise grip. Chimpanzee gestation lasts eight months. The pups are weaned at about the age of three, but generally maintain a close relationship with their mother for several more years. Puberty is reached at the age of eight to ten years and its life expectancy is 50 years in captivity.
Diet
Its diet is mainly vegetarian (fruits, leaves, nuts, roots, tubers, etc.), supplemented by insects and small prey; there are instances of organized hunts. In some cases—such as the killing of leopard cubs—this hunting appears to be a protective effort by the chimpanzees, rather than a hunger motivation. There are documented cases of cannibalism, although it is rare.[citation needed]
Predators
Adult chimpanzees have few natural predators. The most frequent is the leopard, which also prefers other types of prey due to the danger that chimpanzees pose in groups. In second place is the Nile crocodile, which can hunt them when they approach to drink water or cross rivers or streams where the predator lives, but this happens infrequently because chimpanzees know the danger posed by watercourses. and try to avoid them. And the other predator is the African rock python, which also prefers other types of prey because chimpanzees tend to be in groups and this represents a risk.
Behavior
Chimpanzees live in groups called communities that range from 20 to more than 150 members, consisting of several males, females, and young. However, most of the time they move in small groups of a few individuals. Chimpanzees are both arboreal and terrestrial, spending the same amount of time in trees as on the ground. Their usual mode of movement is on all fours, using the soles of the feet and the second phalanges of the fingers, and they can only walk in a bipedal position for short distances.
The common chimpanzee lives in fission-fusion societies, where mating is promiscuous. Chimpanzees can have the following groups: Males only, adult females and her offspring, groups with members of both sexes, a female and her offspring, or solitary individuals. At the center of the social structure are the males, who patrol and guard the members of their group, and participate in foraging. Among males there is usually a dominance hierarchy. However, the unusual fission-fusion social structure, in which portions of the parent group may separate from or rejoin, is highly variable in terms of which particular individuals congregate at any given time. This is mainly because chimpanzees have a high level of autonomy within the fission-fusion groups to which they belong. Chimpanzee communities also have large ranges of territory that overlap with those of other groups.
As a result, individual chimpanzees often forage alone, or in small groups. As indicated, these small groups also emerge in a wide variety of types for a wide variety of purposes. For example, a small troop of males may organize to hunt for meat, while a group consisting of a mature male and a mature female may establish themselves as a group for the purpose of mating. An individual may meet other individuals with some frequency but there may be fights with other individuals not frequented. Due to the frequent variance in the way chimpanzees associate, the structure of their societies is very complicated.
Subspecies
During the XX century, various works have been done to establish a clear taxonomy of the chimpanzee. It was the German zoologist Ernst Schwarz who described most of the currently accepted subspecies, after hundreds of measurements of skeletons and analysis of skins brought to museums. Schwartz, who described the bonobo considered it as a subspecies of Pan troglodytes and not as a separate species. This author established the subspecies of Pan troglodytes as follows:
- Pan troglodytes troglodytes. This subspecies may have a totally black face, similarly as the gorillas present it. Its geographical distribution covers West Africa: Cameroon, Muni River and Gabon.
- Pan troglodytes verus. It has a clearer colouring on the face and in the supraorbital torus, in the juvenile specimens there is evidence of a pattern of white hair in the anal region. Its geographical distribution covers the coast of Guinea from Senegal to Nigeria.
- Pan troglodytes vellerosus.
- Pan troglodytes schweinfurthii. They have the fur longer and more lusty than the other chimpanzees races, also characterized by having in adulthood a baldness similar to that of humans. Its geographical distribution encompasses Central Africa: Great Lakes Region and Eastern Congo (examples of this subspecies were studied by Primatologist Jane Goodall).
Divergence with the bonobo
Recent evidence from DNA analysis suggests that the bonobo (Pan paniscus) and the common chimpanzee diverged about a million years ago. The chimpanzee line diverged from the lineage that led to humans approximately six million years ago. The two species of chimpanzee are equally related to humans and since no other species in the genera Homo, Australopithecus or Paranthropus have survived, are their closest living relatives. The bonobo was not recognized as a separate species until 1929, and in common language the designation "chimpanzee" often applied to both apes. Primatologists prefer to reserve the name "chimpanzee" for Pan troglodytes. Although the anatomical differences between the two species are small, their sexual and social behavior show marked differences. Pan troglodytes possesses group hunting behavior based on beta males led by relatively weak alpha males, an omnivorous diet, and a complex culture with strong bonds.
Chimpanzees and the origin of HIV
There are two types of human immunodeficiency virus (HIV) that infect humans: HIV-1 and HIV-2. HIV-1 is the most virulent and most easily transmitted, and is the cause of the largest source of infections throughout the world; HIV-2 is mainly confined to West Africa. Both types of viruses originated in West and Central Africa by passing from non-human primates to people. HIV-1 evolved from the SIV simian immunodeficiency virus (SIVcpz) found in 35% of wild chimpanzees in Cameroon. Basically, the viruses found in chimpanzees (Pan troglodytes troglodytes) from southeastern Cameroon were very similar to HIV that has spread around the world. The researchers noted that SIV does not cause as severe symptoms in chimpanzees as HIV does in humans, which has prompted a number of investigations. HIV-1 has shown great genetic diversity in southeast Cameroon, suggesting that the virus has been there longer than anywhere else. HIV-2 passed from different species with different SIV chains, found in the gray mangabey (Cercocebus atys) in Guinea-Bissau. Chimpanzees acquired VIS from other monkeys they hunt. Said virus entered their bodies through wounds or bruises.
Threats
It is in danger of extinction due to the loss of its natural environment, hunting and illegal trade, among others.