POLAR BEAR FROM CLIMATE CHANGE
Introduction
The polar bear (Ursus maritimus) is one of the biggest species of bear in the world and
the prime land predator. There is enormous dissimilarity in bulk of male and female
polar bears. The males weight is almost double of the females. Their weight of the body
differs significantly during the period mainly feminine bears which can often double in
weight among earl spring and late summer.
Compared to other bear species, the polar bear has a comparatively small, long and
narrow head, shorter and smaller fur-covered ears, and shorter, more influential claws.
The polar bear is a circumpolar species and is established in arctic regions where there
is closeness to sea ice all the way through much of the year. Polar bear populations are
found in Alaska (USA), Canada, Greenland, the Norwegian Arctic and the Russian
Arctic, and on the ice neighboring the North Pole.
The issue
In considering the probable impact of climate alteration on polar bear populations, there
are two hazardous issues: the connection between the extent of sea-ice and polar bear
ecosystem (Derocher, Lunn & Stirling 2004), and the existing modeling techniques to
generate projections into the future (Sutherland 2006). In 2006 the polar bear was
categorized as being vulnerable (VU) on the IUCN’s (the World Conservation Union)
Red List. Because of the polar bear’s specialty for living on the marine sea ice,
It is mainly vulnerable to major changes in its habitat. A low reproduction rate and a long
generation time means that this species is badly equipped for tackling rapid changes in
its habitat like those now being qualified in the Arctic.
A long-lasting dropping off in sea-ice distribution and thickness can be expected to
impact negatively on polar bears, as the sea-ice provides a platform for journey and
hunting (Derocher 2004).
Findings
One study reported that the previously sea ice break-up in western Hudson Bay has not
yet affected the survival of prime mature polar bears but has likely caused a decrease
in the survival of juvenile, sub-adult and senescent polar bears in the region due to
poorer nutrition (Regehr et al.2007). Mother bears take care of their little cubs for two-
