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, riverine 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. Gorillas are diurnal, with nearly all activity occurring between 6:00 in the morning and 6:00 in the evening. 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.

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) Forest in southwest Uganda.

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.

Orangutan

whale The orca, or "killer," whale is the largest member of the dolphin family. Orcas have long, rounded bodies with large dorsal fins at the middle of their backs. Their black bodies are marked with white patches on the underside and near the eyes.

The average male orca grows to 23 feet long and weighs 7 to 10 tons. Females average 21 feet long and weigh 4 to 6 tons.

The worldwide population of orcas is unknown.

Orcas live 30 to 50 years in the wild.

Found in all oceans of the world, orcas are most common in the Arctic and Antarctic and are often spotted off the west coast of the United States and Canada.

Orcas are found in both coastal waters and open ocean.

Like dolphins, orcas use echolocation - bouncing sound off of objects to determine their location - to hunt and use a series of high-pitched clic