Occurring in suitable mountainous habitat across their extensive range, individual bighorn sheep populations tend to remain localized rather than mixing together. Bighorn sheep are the most common wild sheep in North America.
About 2000 years ago, the wisent — as the European bison is often known — ranged right across Europe and Asia from Britain to Siberia. However, persistent hunting pressure and forest clearance resulted in the species becoming extinct in the wild in 1927.
These particular bears favour thickly forested mountainous areas. They are highly territorial, with individual males occupying areas of up to 100 km2 (40 square miles). They live in the conifer forests of Canada and a few wilderness areas as far south as Mexico.
Only surpassed by the gibbons for grace and agility in the trees, the black spider monkey, with its extremely long limbs and tail, is the most adept and acrobatic of all New World monkeys. This species is light in build, with a small head.
The only species in its genus, the blackbuck is one of the few antelope in which the coloration of male and female is dissimilar. The dominant male in the herd is dark, almost black on back and sides and has long, spirally twisted horns.
Blue whales are also probably the biggest creatures that have ever lived. It has a blue-grey body, with spots along its back and a pale pleated throat. The blue whale may weigh more than 161 US t (146 te). Its body is streamlined and, despite its enormous bulk.
Unlike many wild cats the bobcat has a short tail, reflecting its preference for life on the ground rather than climbing trees. They are especially common in the south-eastern United States, where there is a population of more than one million.
Bongos are forest antelopes. They have shorter legs than other antelopes, which is a typical body form of forest herbivores. Long legs are used for running quickly and this is not possible in dense jungle, whereas shorter legs make the bongos more sure-footed.
Although commonly known as the pygmy chimpanzee, this species is often the same size as its close relative - Pan troglodytes - and is also very similar in appearance, though less powerfully built. Bonobos are very social animals, and live in groups.
This is one of the most common and familiar dolphin species. It is found worldwide but often appears along the Atlantic coast of North America, from Cape Hatteras in North Carolina to Argentina, and along the Pacific up to northern California.