Chimpanzee
October 18th, 2008
Chimpanzees are members of the Hominidae family, along with gorillas, humans, and orangutans. The two chimpanzee species are the closest living relatives to humans; all being members of the Hominini tribe (along with extinct species of Hominina subtribe). Chimpanzees are the only known members of the Panina subtribe.
Chimpanzees rarely live past the age of 40 in the wild, but have been known to reach the age of more than 60 in captivity. Cheeta, star of Tarzan is still alive as of 2008 at the age of 76, making him the oldest known chimpanzee in the world.
The Common Chimpanzee and the Bonobo do not swim. It has been suggested that the formation of the Congo River 1.5-2 million years ago separated the ancestors of the Bonobo south of the river, from the ancestors of the Common Chimpanzee to the north of the river. This event is thought to have triggered the speciation of the two chimpanzee species.
Africans have had contact with chimpanzees for millennia. Chimpanzees have been kept as domesticated pets for centuries in a few African villages, especially in Congo. The first recorded contact of Europeans with chimps took place in present-day Angola during the 1600s. The diary of Portuguese explorer Duarte Pacheco Pereira (1506), preserved in the Portuguese National Archive (Torre do Tombo), is probably the first European document to acknowledge that chimpanzees built their own rudimentary tools.
The first use of the name "chimpanzee", however, did not occur until 1738. The name is derived from a Tshiluba language term "kivili-chimpenze", which is the local name for the animal and translates loosely as "mockman" or possibly just "ape". The colloquialism "chimp" was most likely coined some time in the late 1870s. Biologists applied Pan as the genus name of the animal. Chimps as well as other apes had also been purported to have been known to Western writers in ancient times, but mainly as myths and legends on the edge of Euro-Arabic societal consciousness, mainly through fragmented and sketchy accounts of European adventurers. Apes are mentioned variously by Aristotle, as well as the Bible, where apes and baboons are described as having been collected by Solomon in 1 Kings 10:22.
When chimpanzees first began arriving on the European continent, European scientists noted the inaccuracy of some ancient descriptions, which often reported that chimpanzees had horns and hooves. The first of these early transcontinental chimpanzees came from Angola and were presented as a gift to Frederick Henry, Prince of Orange in 1640, and were followed by a few of its brethren over the next several years. Scientists who examined these rare specimens were baffled, and described these first chimpanzees as "pygmies", and noted the animals' distinct similarities to humans. The next two decades would see a number of the creatures imported into Europe, mainly acquired by various zoological gardens as entertainment for visitors.
Darwin's theory of evolution (published in 1859) spurred scientific interest in chimpanzees, as in much of life science, leading eventually to numerous studies of the animals in the wild and captivity. The observers of chimpanzees at the time were mainly interested in behaviour as it related to that of humans. This was less strictly and disinterestedly scientific than it might sound, with much attention being focused on whether or not the animals had traits that could be considered 'good'; the intelligence of chimpanzees was often significantly exaggerated. At one point there was even a scheme drawn up to domesticate chimpanzees in order to have them perform various menial tasks (i.e. factory work). By the end of the 1800s chimpanzees remained very much a mystery to humans, with very little factual scientific information available.
The 20th century saw a new age of scientific research into chimpanzee behaviour. Before 1960, almost nothing was known about chimpanzee behaviour in their natural habitat. In July of that year, Jane Goodall set out to Tanzania's Gombe forest to live among the chimpanzees. Her discovery that chimpanzees made and used tools was groundbreaking, as humans were previously believed to be the only species to do so. The most progressive early studies on chimpanzees were spearheaded primarily by Wolfgang Köhler and Robert Yerkes, both of whom were renowned psychologists. Both men and their colleagues established laboratory studies of chimpanzees focused specifically on learning about the intellectual abilities of chimpanzees, particularly problem-solving. This typically involved basic, practical tests on laboratory chimpanzees, which required a fairly high intellectual capacity (such as how to solve the problem of acquiring an out-of-reach banana). Notably, Yerkes also made extensive observations of chimpanzees in the wild which added tremendously to the scientific understanding of chimpanzees and their behaviour. Yerkes studied chimpanzees until World War II, while Köhler concluded five years of study and published his famous Mentality of Apes in 1925 (which is coincidentally when Yerkes began his analyses), eventually concluding that "chimpanzees manifest intelligent behaviour of the general kind familiar in human beings ... a type of behaviour which counts as specifically human" (1925).
Common Chimpanzees have been known to attack humans on occasion. There have been many attacks in Uganda by chimpanzees against human children; the results are sometimes fatal for the children. Some of these attacks are presumed to be due to chimpanzees being intoxicated (from alcohol obtained from rural brewing operations) and mistaking human children for the Western Red Colobus, one of their favourite meals. The dangers of careless human interactions with chimpanzees are only aggravated by the fact that many chimpanzees perceive humans as potential rivals, and by the fact that the average chimpanzee has over 5 times the upper-body strength of a human male. As a result virtually any angered chimpanzee can easily overpower and potentially kill even a fully grown man, as shown by the attack and near death of former NASCAR driver Saint James Davis.
The August, 2008, issue of the American Journal of Primatology reports results of a year-long study of chimpanzees in Tanzania’s Mahale Mountains National Park which produced evidence that chimpanzees are becoming sick from viral infectious diseases they have likely contracted from humans. Molecular, microscopic and epidemiological investigations demonstrated that the chimpanzees living at Mahale Mountains National Park have been suffering from a respiratory disease that is likely caused by a variant of a human paramyxovirus.
Many human fossils have been found, but chimpanzee fossils were not described until 2005. Existing chimpanzee populations in West and Central Africa do not overlap with the major human fossil sites in East Africa. However, chimpanzee fossils have now been reported from Kenya. This would indicate that both humans and members of the Pan clade were present in the East African Rift Valley during the Middle Pleistocene.
L'Hoest's Monkey
July 17th, 2008
L'Hoest's Monkey is a member of the genus Cercopithecus, and closely resembles Hamlyn's Monkey in size and distribution. Recent studies have shown that the subspecies C. l'hoesti preussi on the west coast of Africa is distinct enough and has been elevated to a full species, Preuss's Monkey C. preussi. Together with the Sun-tailed Monkey, C. solatus, Preuss's and L'Hoest's make up a tight grouping within the Cercopithecus genus.
L'Hoest's Monkey occurs in northeastern Democratic Republic of the Congo, Rwanda, Burundi, and western Uganda. It is a forest monkey, which is typical of the moist and high primary forests. It will occupy a range of different kinds of forested areas, including gallery forest, mature lowland rain forests, wooded savanna at mountain slopes, and forest borders. However, it also will live on cultivated lands. In lowland forests it shows a preference toward areas where the forest is regenerating, while in mountain areas it will frequent the mature, tangled, undergrowth below the broken canopy. One study found this population only above 900 m but another found it as low as 610 m (2000 ft). Another mostly observed it from 1500 to 2500 m. They make their homes in remarkable nests in trees.
This breed of monkey lives in fairly small groups dominated by females and have only a single male. The females are usually related, while the male stays only a couple of weeks or at most a couple of years. The adult male will make very loud and distinct calls. They are active during the day, mostly during early morning and late afternoon. They sleep in trees in a sitting position, usually either holding branches or each other. When they are alarmed or see they are being observed they will flee and take shelter in trees, and after become very still. They are mostly terrestrial.
L'Hoest's Monkey breeds seasonally, which depends on the area. After about a five month gestation period, a single young will be born. The mother gives birth typically at night and where ever she happens to be at the time. Birth usually occurs at the end of the dry season, which allows lactation when rainfall is highest. She will eat the placenta and lick the baby clean while it hangs onto to her belly. The other females in the group will show much interest in the newborn and will try to hold it. After a few months nursing becomes less frequent, but will continue for about two years when there is another birth. When male offspring reach sexual maturity they will leave the group. In captivity they have been known to live for more than 30 years.
