Gorilla Research Paper

Table of contents

· Gorilla …………………………………………………………………pg.3
· Physical characteristics and behavior…………………………….. pg.4
· Endangerment………………………………………………………...pg.5

Gorilla’s

The gorilla is the largest primate, weighing as much as 275 kg (600 lb). Gorillas are forest-associated animals. Most gorillas inhabit lowland tropical rainforests and montane rainforests between 1500 - 3500 m (4900 - 11,500 ft). Different populations have exhibited preferences for forest margins, secondary forest, swamp forests, bamboo forests, riverside forests and primary forest. The diets of the eastern and western gorilla populations differ considerably. Eastern animals are predominantly folivorous, but those in the west eat great quantities
of fruit. Gorillas spend most of their time foraging on the ground, although young animals and females, particularly lowland gorillas, frequently feed and sleep in trees.Before nightfall, they settle into their nests, which are freshly constructed each night.
Gorillas live in groups ranging in size from 2 individuals to as many as 38. The western populations have smaller group sizes, averaging 5 members, whereas eastern groups average 9 (website).
Gorillas are divided into two species and either four or five subspecies. Its DNA is 97%-
98% identical to that of a human, and are the next closest living relatives to humans after the two chimpanzee species. The gorilla is found in two principal areas: equatorial West
Africa and eastern Central Africa. The western lowland gorilla subspecies occurs in West
Africa and is the most widespread. The recently identified Cross River gorilla, the rarest of the gorilla subspecies, is found on both sides of the Nigeria-Cameroon border. The eastern lowland gorilla subspecies occurs in the eastern portion of The
Democratic
Republic of the Congo. The mountain gorilla subspecies occurs in two populations, one on the extinct volcanoes of the Virunga Range along the borders of Rwanda, Uganda and
The Democratic Republic of the Congo; and the other in the Bwindi (Impenetrable)

Physical characteristics and behavior Gorillas move around by knuckle-walking.
Adult males range in height from 165-175 cm (5 ft 5 in – 5 ft 9 in), and in weight from 140–200 kg (310–440 lb). Adult females are often half the size of a silverback, averaging about 140 cm (4 ft 7 in) tall and 100 kg (220 lb). Occasionally, a silverback of over 183 cm (6 ft) and 225 kg (500 lb) has been recorded in the wild. However, obese gorillas in captivity have reached a weight of 270 kg (600 lb).Gorillas have a facial structure which is described as mandibular prognathism, that is, their mandible protrudes farther out than the maxilla. Eastern gorillas are darker colored than Western gorillas, with Mountain gorilla being the darkest of all. Mountain gorillas also have the thickest hair. The Western lowland gorilla can be brown or grayish with a reddish forehead. In addition, gorillas that live in lowland forests are more slender and agile than the more bulky Mountain gorilla. Almost all gorillas share the same blood type B and, like humans, have individual finger prints. The gorilla is primarily terrestrial but is fully capable of climbing. Some have been observed feeding in trees at heights of 40 m (130 ft), and even a large male, weighing at least 200 kg (440 lb), frequently climbed to 20 m (65 ft). Contrary to general opinion, the gorilla is not afraid of water. Recent studies of the western lowland gorilla have shown that it is quite happy to wade around in swamp forests in search of edible aquatic plants. Gorillas are
now known to wade freely through swamps and streams. Gorillas spend most of their time foraging on the ground, although young animals and females, particularly lowland gorillas, frequently feed and sleep in trees.(Stuart & Stuart, 1996) A silverback is an adult male gorilla, typically more than 12 years of age and named for the distinctive patch of silver hair on his back. A silverback gorilla has large canine teeth that come with maturity. Black backs are sexually mature males of up to 11 years of age. Silverbacks are the strong, dominant troop leaders. Each typically leads a troop of 5 to 30 gorillas and is the center of the troop's attention, making all the decisions, mediating conflicts, determining the movements of the group, leading the others to feeding sites and taking responsibility for the safety and well-being of the troop. Younger males called blackbacks may serve as backup protection. Males will slowly begin to leave their original troop when they are about 11 years old, traveling alone or with a group of other males for 2–5 years before being able to attract females to form a new group and start breeding. While infant gorillas normally stay with their mother for 3–4 years, silverbacks will care for weaned young orphans, though never to the extent of carrying the little gorillas.

If challenged by a younger or even by an outsider male, a silverback will scream, beat his chest, break branches, bare his teeth, then charge forward. Sometimes a younger male in the group can take over leadership from an old male. If the leader is killed by disease, accident, fighting or poachers, the group will split up, as the animals disperse to look for a new protective male. Very occasionally, a group might be taken over in its entirety by another male. There is a strong risk that the new male may kill the infants of the dead silverback.(website). Endangerment
Hunting and forest clearance for agriculture and timber are the main threats. African lowland and montane forests are rapidly being destroyed to make way for food production uses such as cropping and livestock grazing. In addition, gorillas are killed in retaliation for crop-raiding. In Central Africa, commercial logging and petroleum exploitation are becoming an increasingly significant threat to the habitat of the gorilla. The internal trade in bushmeat, which occurs over much of the lowland gorillas' ranges, is now a threat. In recent years, human population pressures on the forest habitat of the eastern lowland gorilla have become worse due to the nearly 1 million refugees from nearby Rwanda and Burundi. Both species of gorilla are endangered, and have been subject to intense poaching for a long time. In 2004 a population of several hundred gorillas in the Odzala National Park in Republic of Congo, was essentially wiped out by the Ebola virus. A 2006 study published in Science concluded that more than 5,000 gorillas may have died in recent outbreaks of the Ebola virus in central Africa. The researchers indicated that in conjunction with commercial hunting of these apes creates "a recipe for rapid ecological extinction". (website)

Works cited
· http://en.wikipedia.org/wiki/Gorilla
· http://www.animalinfo.org/species/primate/gorigori.htm
· Stuart & Stuart. 1996. Africa's Vanishing Wildlife. Smithsonian Institution Press, Washington, D.C. USA.