Thursday, January 27, 2011

Why is the polar bear so important? - Send a Polar Bear eCard (below)

Large carnivores - those that are at the apex  or top of the food chain - are particularly sensitive indicators of the health of an ecosystem... in this case, the Arctic. 

And of all of the wildlife species in the Arctic, the polar bear is perhaps the most fitting icon for this ecoregion. 

Its amazing adaptations to life in the rugged Arctic environment and dependence on sea ice make them so impressive, and yet so vulnerable. 

This is why polar bears help us gain an understanding of what is happening throughout the Arctic, as a polar bear at risk may signal something is wrong elsewhere in the arctic marine ecosystem. 

All recent indicators show that sea ice in the Arctic is melting at an alarming rate, a problem that needs to be addressed immediately if polar bears, and other species unique to the region, are to survive.

What WWF is doing for polar bears

WWF works to:
  1. Negotiate with governments, industry, and individuals to reduce greenhouse gas emissions and mitigate climate change.
  2. Promote sustainable consumptive and non-consumptive use of polar bears that directly affect the species, such as hunting, poaching, industrial take, illegal trade, and unsustainable tourism.
  3. Protect critical habitat including important movement corridors, and denning habitat.
  4. Prevent or remove direct threats from industrial activity such as oil and gas development, and arctic shipping.
  5. Fund field research by the world's foremost experts on polar bears to find out how global warming will affect the long-term condition of polar bear.
The actions we take include providing support for and communication of key science that will help us build resilience; engaging with indigenous and local communities to reduce human-wildlife conflicts and work towards sustainable development opportunities; and drafting and spearheading management solutions that address the major threats of climate change and industrialisation of the Arctic.

Polar bear's epic nine day swim in search of sea ice
A polar bear swimming in Arctic waters (c) Mila Zinkova

A polar bear swam continuously for over nine days, covering 687km (426 miles), a new study has revealed.
Scientists studying bears around the Beaufort sea, north of Alaska, claim this endurance feat could be a result of climate change.
Polar bears are known to swim between land and sea ice floes to hunt seals.
But the researchers say that increased sea ice melts push polar bears to swim greater distances, risking their own health and future generations.
 We are in awe that an animal that spends most of its time on the surface of sea ice could swim constantly for so long in water so cold. 
George M. Durner
In their findings, published in Polar Biology, researchers from the US Geological Survey reveal the first evidence of long distance swimming by polar bears (Ursus maritimus).
"This bear swam continuously for 232 hours and 687 km and through waters that were 2-6 degrees C," says research zoologist George M. Durner.
"We are in awe that an animal that spends most of its time on the surface of sea ice could swim constantly for so long in water so cold. It is truly an amazing feat."
Although bears have been observed in open water in the past, this is the first time one's entire journey has been followed.
By fitting a GPS collar to a female bear, researchers were able to accurately plot its movements for two months as it sought out hunting grounds.
The scientists were able to determine when the bear was in the water by the collar data and a temperature logger implanted beneath the bear's skin.
The study shows that this epic journey came at a very high cost to the bear.
"This individual lost 22% of her body fat in two months and her yearling cub," says Mr Durner.
"It was simply more energetically costly for the yearling than the adult to make this long distance swim," he explains.
Polar bear and cub (c) Andrew Wilson /
Swimming long distances puts cubs at risk

Mr Durner tells the BBC that conditions in the Beaufort sea have become increasingly difficult for polar bears.
"In prior decades, before 1995, low-concentration sea ice persisted during summers over the continental shelf in the Beaufort Sea."
A polar bear (c) Tom Mangelsen /
Polar bears are the world's largest land carnivores
They have black skin and transparent hairs but appear white, turning yellow with age
On land, they can reach up to 40 kph (25 mph) when sprinting short distances to catch prey
"This means that the distances, and costs to bears, to swim between isolated ice floes or between sea ice and land was relatively small."
"The extensive summer melt that appears to be typical now in the Beaufort Sea has likely increased the cost of swimming by polar bears."
Polar bears live within the Arctic circle and eat a calorie-rich diet of ringed seals (Pusa hispida) to survive the frozen conditions.
The bears hunt their prey on frozen sea ice: a habitat that changes according to temperature.
"This dependency on sea ice potentially makes polar bears one of the most at-risk large mammals to climate change," says Mr Durner.
The IUCN red list identifies polar bears as a vulnerable species, citing global climate change as a "substantial threat" to their habitat.

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