Minggu, 19 April 2015

Polar Bear


Polar bears

The largest of all bears, the polar bear feeds exclusively on meat , males can reach over 1750 lbs (800 kgs) .

Evolution

The polar bear closest relatives are the brown bears, and it is believed 1 million years ago some of these bears became isolated and lived along the edges of the Arctic Ocean . Here the abundant food source of marine mammals; seals , walruses , and even whales, as they learned to prey on these species the polar bear evolved to a harsher environment. Developing white coats of fur and thick layers of fat, over a short period of evolutionary time the polar bear has become what we know of today.

Habitat

Most polar bears in the high Arctic live permanently on the frozen Arctic Ocean following the sea ice edges as its slowly extends southwards moving between ice flows the polar bear will swim for miles to another floating ice pack searching out for food. Some individual bears will travel a few thousand square miles on stable year-round ice, others have been known to cover 116,000 sq miles (300,000 km) some ice like the Bering Sea will move 620 miles (1000 km) between the summer and winter months.

Diet

Meat makes up 90 percent of their food, hunting seals is a major source of food but not the only one , other food includes walrus, seabirds that were on this the sea floating and taken by surprise, Narwals , Beluga whales will find an open crack in the sea ice to breath where the polar bear will lay and wait .

Mating

The female bear can be four times smaller than the male, quite often the cubs are killed by the male. Because of this females will den miles away often on land. Polar bears mate in the springtime from march through too late May. The fertilized eggs remains in the blastocyst stage for around four months, when it is implanted in the uterus it begins to develop around late May. Gestation period lasts about three months and the young are born between November to January, where they will spend their time resting with the mother. The polar bear cubs stay with the mother for two and a half years, living in a harsh environment there is a lot of skills to be learned .

Polar bear facts

Size: 6 to 11 ft. ( 1.5 to 3 m )

Weight : 660 to 1750 lbs (300 to 800 kgs)

Reproduction: First breeds fourth seven years . Has one to three cubs every three or four years.

Life span : 25 to 30 years.

Classification

Kingdom
Phylum
Class
Order
Family
ANIMALIA
CHORDATA
MAMMALIA
CARNIVORA
URSIDAE

Scientific Name:
Ursus maritimus
Species Authority:
Phipps, 1774
Common Name(s):
English
Polar Bear
French
Ours polaire, Ours blanc
Spanish
Oso Polar
Synonym(s):
Thalarctos maritimus (Phipps, 1774)
Taxonomic Notes:
Phipps (1774) first described polar bears as a distinct species and named it Ursus maritimus. Other names were suggested including ThalassarctosThalarctos andThalatarctos ultimately settling on Ursus (Thalarctosmaritimus Erdbrink (1953) and Thenius (1953) based on interbreeding between brown bears (Ursus arctos) and polar bears in zoos. Based on the fossil record and evolution KurtĂ©n (1964) recommended the Phipps (1774) name Ursus maritimus, which was promoted by Harrington (1966), Manning (1971) and Wilson (1976) and is used today (see DeMaster and Stirling 1988, Wilson and Reeder 1993, Amstrup 2003 for review and references).



Source: http://www.iucnredlist.org/
            http://www.animaltrial.com/

Tidak ada komentar:

Posting Komentar