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Polar Bears and Conservation
Posted By G Monkie On February 3, 2010 @ 8:30 am In Nature / Non Human Stories | No Comments
Today is Polar Bear day at G Living. Enjoy the photos and the information about this truly amazing earthling. The following information is by : Polar Bears International
Polar Bear Status Report. Polar bears are a potentially threatened species living in the circumpolar north. They are animals which know no boundaries.They pad across the ice from Russia to Alaska, from Canada to Greenland and onto Norway’s Svalbard archipelago. No adequate census exists on which to base a worldwide population estimate, but biologists use a working figure of 20,000 to 25,000 bears with about sixty percent of those living in Canada.
In areas where long-term studies are available, populations are showing signs of stress. Canada’s Western Hudson Bay population has dropped 22% since the early 1980s. The declines have been directly linked to an earlier ice break-up on Hudson Bay. A long-term study of the Southern Beaufort Sea population, which spans the northern coast of Alaska and western Canada, has revealed a decline in cub survival rates and in the weight and skull size of adult males. Such declines were observed in Western Hudson Bay bears prior to the population drop there. Another population listed as declining is Baffin Bay. According to the most recent report from the Polar Bear Specialist Group, the harvest levels from Nunavut when combined with those from Greenland (which were thought to be much lower than they actually are) has resulted in this shared population being in a non-sustainable harvest situation, meaning the population is at great risk of a serious decline. The harvest is thought to be several times above what is sustainable.
Some Native communities in Canada have been reporting increasing numbers of polar bears on land. Traditional hunters believe this indicates an increased population, although the increased presence on land may, in fact, be related to shrinking sea ice and changes in the bears’ distribution patterns. Data is needed to understand the change. The U.S. Fish and Wildlife Service states, "In the declining polar bear population of Canada’s Western Hudson Bay, extensive scientific studies have indicated that the increased observation of bears on land is a result of changing distribution patterns and a result of changes in the accessibility of sea ice habitat."
Climate change is the main threat to polar bears today. A diminishing ice pack directly affects polar bears, as sea ice is the platform from which they hunt seals. Although the Arctic has experienced warm periods before, the present shrinking of the Arctic’s sea ice is rapid and unprecedented.
Two-thirds of the world’s polar bears will be killed off by 2050 — and the entire population gone from Alaska — because of thinning sea ice from global warming in the Arctic, government scientists forecast.
In the 1960s and 1970s, hunting was the major threat to the bears. At the time, polar bears were under such severe survival pressure from hunters that a landmark international accord was reached, despite the tensions and suspicions of the Cold War. The International Agreement on the Conservation of Polar Bears was signed in Oslo, November 15, 1973 by the five nations with polar bear populations: Canada, Denmark (Greenland, Norway, the U.S., and the former U.S.S.R.
The polar bear nations agreed to prohibit random, unregulated sport hunting of polar bears and to outlaw hunting the bears from aircraft and icebreakers as had been common practice. The agreement also obliged each nation to protect polar bear denning areas and migration patterns and to conduct research relating to the conservation and management of polar bears. Finally, the nations agreed to share their polar bear research findings with each other. Member scientists of the Polar Bear Specialist Group now meet every three to four years under the auspices of the IUCN World Conservation Union to coordinate their research on polar bears throughout the Arctic.
The Oslo agreement was one of the first and most successful international conservation measures enacted in the 20th century. Its legacy continues today, with member scientists from each nation continuing to work together in face new threats to the bears including climate change, pollution, industrial activities, and poaching.
About the Polar Bear
Scientists believe that Ursus maritimus, the "sea bear," evolved about 200,000 years ago from brown bear ancestors. The bears are superbly adapted for survival in the Far North.
Polar bears range throughout the Arctic in areas where they can hunt seals at open leads. The five "polar bear nations" where the ice bears are found include the U. S. (Alaska), Canada, Russia, Denmark (Greenland), and Norway.
Polar bears are the world’s largest land predators They top the food chain in the Arctic, where they prey primarily on seals.
Adult male polar bears weigh from 775 to more than 1,500 pounds. Females are considerably smaller, normally weighing 330 to 550 pounds.
Polar bears only rarely catch seals in open water. They are far more successful at hunting them on the sea ice. On the ice, the bears catch their prey when they surface to breathe.
Rifts in the ice, called leads, give seals access to oxygen. Seals also surface to breathe at polynyas, areas of open water surrounded by ice.
Polynyas are created by a combination of winds, tidal currents, and upwellings of water. They remain open throughout the winter months.
Greenland and Norway have the most polar bears, while a quarter of them live mainly in Alaska and travel to Canada and Russia. The agency says their range will shrink to no longer include Alaska and other southern regions.
In addition to surfacing at leads and polynyas, seals cut breathing holes in the ice. The Inuit call these holes aglus.
In fall, each seal cuts ten to fifteen aglus in the ice, using the sharp claws on their foreflippers. They keep the aglus open throughout the winter, even when the ice is six feet deep.
Seals swim to the surface to breathe every five to fifteen minute. But because they visit as many as fifteen breathing holes, a polar bear’s wait for its prey can be long.
Polar bears locate breathing holes with their powerful sense of smell. When a bear finds an aglu, it waits patiently for the seal to surface — which can take hours or days.
Polar bears depend on the presence of ice for access to seals. In summer, when the floes retreat north, polar bears will travel hundreds of miles to maintain contact with their prey.
Between summer and winter the amount of ice-covered water can change rapidly. Polar bears learn to follow the ice to stay with their food source.
Those polar bears that are stranded on land in summer must stay there until the ice forms again in fall. On land, the bears face lean times, for they seldom catch seals without a platform of ice.
Please learn more about the Polar Bear and our effects on their lives at: polarbearsinternational.org
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