Tuesday, December 18, 2007
A semi-aquatic marine mammal, the polar bear has adapted for life on a combination of land, sea, and ice, and is the apex predator within its range. It feeds mainly on seals, young walruses, and whales, although it will eat anything it can kill.
A polar bear's fur provides camouflage and insulation. Although the fur appears white, in fact the individual hairs are translucent, like the water droplets that make up a cloud; the coat may yellow with age. Stiff hairs on the pads of a bear's paws provide insulation and traction on the ice.
Polar bears are enormous, aggressive, curious, and potentially dangerous to humans. Wild polar bears, unlike most other bears, are barely habituated to people and will quickly size up any animal they encounter as potential prey. Males are normally solitary except for mating season, and females are usually social towards one another. Despite a recurring internet meme that all polar bears are left-handed, there is no scientific evidence to support such a contention. Researchers studying polar bears have failed to find any evidence of left-handedness in all bears and one study of injury patterns in polar bear forelimbs found injuries to the right forelimb to be more frequent than those to the left, suggesting, perhaps, right-handedness.
Polar bears are excellent swimmers and have been seen in open Arctic waters as far as 60 miles (100 km) from land. In some cases they spend half their time on ice floes. Their 12 cm (5 in) layer of fat adds buoyancy in addition to insulating them from the cold. Recently, polar bears in the Arctic have undertaken longer than usual swims to find prey, resulting in four recorded drownings in the unusually large ice pack regression of 2005....(more on www.wikipedia.org)
Thursday, December 6, 2007
The giraffe (Giraffa camelopardalis) is an African even-toed ungulate mammal, the tallest of all land-living animal species. Males can be 4.8 to 5.5 metres (16 to 18 feet) tall and weigh up to 1,360 kilograms (3,000 pounds). The record-sized bull was 5.87 m (19.2 feet) tall and weighed approximately 2,000 kg (4,400 lbs.). Females are generally slightly shorter and weigh less than the males do.
Male giraffes are around 16-19 feet (4.5-5.5 metres) tall at the horn tips, and weigh 1700-4200 lb. (770-1900 kg) Females are one to two feet (30-60 cm) shorter and weigh several hundred pounds less than males. Giraffes have spots covering their entire bodies, except their underbellies, with each giraffe having a unique pattern of spots.
HornsBoth sexes have horns, although the horns of a female are smaller. The prominent horns are formed from ossified cartilage and are called ossicones. The appearance of horns is a reliable method of identifying the sex of giraffes, with the females displaying tufts of hair on the top of the horns, where as males' horns tend to be bald on top — an effect of necking in combat. Males sometimes develop calcium deposits which form bumps on their skull as they age, which can give the appearance of up to three further horns.
NeckGiraffes have long necks, which they use to browse the leaves of trees. They possess seven vertebrae in the neck (the usual number for a mammal) that are elongated. The vertebrae are separated by highly flexible joints. The base of the neck has spines which project upward and form a hump over the shoulders....(more on www.wikipedia.com)
Monday, December 3, 2007
The reindeer, known as caribou when wild in North America, is an Arctic and Subarctic-dwelling deer (Rangifer tarandus).
The name Caribou comes from Mi'kmaq qalipu, meaning "snow-shoveler", referring to its habit of pawing through the snow for food. In Inuktitut the caribou is known by the name tuttuk (Labrador dialect).
The reindeer is distributed throughout a number of northern locales. Reindeer are found in northern Scandinavia; at Spitsbergen; in European parts of Russia including northern Russia and Novaya Zemlya; in the Asian parts of Russia; northern Mongolia; northeastern China to the Pacific Ocean; in North America (where it is called the caribou); on Greenland, Canada and Alaska. Until the early 19th century it still occurred in southern Idaho.
The weight of a female varies between 60 and 170 kg (132 - 375 lb). In some subspecies of reindeer, the male is slightly larger; in others, the male can weigh up to 300 kg (661 lb). Both sexes grow antlers, which (in the Scandinavian variety) for old males fall off in December, for young males in the early spring, and for females, summer. The antlers typically have two separate groups of points (see image), a lower and upper. Domesticated reindeer are shorter-legged and heavier than their wild counterparts. The caribou of North America can run at speeds up to 80 km/h (50 MPH) and may travel 5,000 km (3,000 mi) in a year.
In the wild, most caribou migrate in large herds between their birthing habitat and their winter habitat. Their wide hooves help the animals move through snow and tundra; they also help propel the animal when it swims. About 1 million live in Alaska, and a comparable number live in northern Canada....(more on www.wikipedia.com)