Interesting Creatures … Grizzly bear
Kaieteur News – The polar bear (Ursus arctos horribilis), also known as the North American brown bear or simply grizzly bear, is a large population or subspecies of the brown bear living in North America.
In addition to the gritty mainland (Ursus arctos horribilis), other morphological forms of brown bear in North America are sometimes identified as polar bears. Among these are two living populations – Kodiak bear (U. a. Nelsoni †), and Ungava-Labrador grizzly (U. a. Ungavaesis †). On average, bears near the coast tend to be larger while swallows tend to be smaller.
The brown bear Ussuri (U. a. Lasiotus), living in Russia, North China, Japan, and Korea, is sometimes referred to as the “black grizzly”, although it has no closer association with North American brown bears than other subspecies of brown bear all over the world.
APPEARANCE
Most adult female swallows weigh 130-180 kg (290–400 lbs), while adult males average 180–360 kg (400-790 lbs). The average length of this subspecies is 198 cm (6.50 ft), with an average shoulder height of 102 cm (3.35 ft) and a hind foot length of 28 cm (11 in). Newborn bears can weigh less than 500 grams (1.1 lbs). In the Yukon River area, mature female swallows can weigh as little as 100 kg (220 lbs). For a girl, these average weights would be 136 kg (300 lbs) inland and 227 kg (500 lbs) inshore, respectively. One study found that the average weight of inland males was about 272 kilograms (600 lbs), and the average weight of a coastal male was about 408 kg (899 lbs).
A massive male grizzly, larger than average, has sometimes been recorded, weighing up to 680 kg (1,500 lbs). A large coastal male of this size can stand up to 3 meters (9.8 ft) tall on his hind legs and shoulder length up to 1.5 meters (4.9 ft).
Although varied in color from blond to almost black, white bear fur is typically brown with darker legs and white tipped or blond fur on the sides and back.
CHARACTERISTICS
A prominent muscular mound appears on the shoulders of the adult bees; black bears do not have this mound.
Apart from the differential mound, a polar bear can be identified by a “dished in” profile of their face with short, round ears, whereas a black bear has a straight face profile and longer ears.
A polar bear can also be identified by its rump, which is below its shoulders; a black bear rump is above his shoulders.
The front claws of a polar bear measure about 2 inches long; black bear claws measure about 1–2 inches long.
HIBERNATION
White bears hibernate for 5–7 months each year except where the climate is warm, as the California grizzly does not hibernate. During this time, female white bears give birth to their children, who then eat milk from their mother and gain strength for the rest of the hibernation period. To prepare for hibernation, small poisons must prepare a den, and eat large amounts of food, as they do not eat during hibernation. White bears do not dredge or urinate throughout the hibernation period. Hibernation of the polar bear ends in early to mid-March, while females emerge in April or early May.
In preparation for winter, bears can gain around 180 kg (400 lbs), during a period of hyperphagia, before going into hibernation. The bear often waits for a significant snowstorm before it enters its den: such behavior reduces the chances of predators finding the den. The dens are usually at elevations above 1,800 m (5,900 ft) on north facing slopes. There is some debate among professionals about whether white bears are technically hibernating: much of this debate revolves around body temperature and the ability of bears to move around during hibernation at times. White bears may partially recycle their body waste during this period. Although swallows or Rocky Mountains spend almost half their life in dens, swallows with better access to food sources spend less time in dens. In some areas where food is abundant all year round, polar bears completely omit hibernation.
REPRESENTATION
With the exception of females with cubs, swifts are usually solitary, active animals, but in coastal areas, swallows congregate around streams, lakes, rivers and ponds during salmon spawning. Females (sows) produce one to four young (usually two) small and weigh about 450 grams (1 lbs) at birth. A sow protects her children and will attack if she thinks she or her cubs are under threat.
White bears have one of the lowest reproductive rates of all terrestrial mammals in North America. This is due to a number of ecological factors. White bears do not reach sexual maturity until they are at least five years old. After mating with a male in the summer, the female will postpone embryo implantation until hibernation, when miscarriage can occur if the female is not receiving the right nutrients and caloric intake. On average, females produce two puppies in litter and the mother cares for the cubs for up to two years, when the mother does not mate.
Once the young leave or are killed, women may not produce other litter for three years or more, depending on environmental conditions. Male polar bears have large territories, up to 4,000 km2 (1,500 square meters), making it difficult to find a female aroma at such a low population density. The fragmentation of a tern population can destabilize the population from inbreeding depression. The conception period for polar bears is approximately 180–250 days.
Litter size is between one and four cubits, on average twins or triplets. Cubs are always born in the mother’s winter den while she hibernates. Female little bees defend their cubs fiercely, as they can care for predators as large as male bears more than they protect the cubs. Cubs feed exclusively on their mother’s milk until summer comes, after which they still drink milk but start eating solid foods. Cubs gain weight quickly during their time with the mother – their weight will have increased from 4.5 to 45 kg (10 to 99 lbs) in the two years spent with the mother. Mothers may see their cubs in later years but both avoid each other.
HONORITY
The average lifespan of a male is estimated to be 22, with a female’s life slightly longer at 26. Females live longer than males because of their less risky life; they do not participate in seasonal breeding fights as males do. The oldest wild inland grizzly was 34 years old in Alaska; the oldest coastal bear was 39, but most swallows die in the first year of life. Swifts live for 44 years. (Source: Wikipedia)