100 Places To Remember: Western Hudson Bay, Canada
Geschreven op 15-3-2010 - Erik van Erne. Geplaatst in Natuur
At the Top of the Food Chain. With a thick covering of blubber, two layers of fur, small ears and a short tail, the polar bear is perfectly adapted for survival in the icy north. For the polar bear the problem is not the cold but overheating, which is why it prefers to move at a leisurely pace.
The polar bear roams the Arctic Ocean and surrounding seas, including Canadas Hudson Bay to the south. As the animal at the top of the food chain in the Arctic, the polar bear spends most of the year on the frozen sea, hunting for seals.
The bear uses its acute sense of smell to locate seals breathing holes in the ice. Patiently, it awaits the moment when its prey surfaces to breathe, which might be hours or even days later.
In Western Hudson Bay, the ice begins to melt and break up in late spring. Unable to hunt seals until the sea freezes again, the polar bear enters a state of hibernation and lives off its fat reserves.
With an estimated global population of 22-25,000, the polar bear is classified as an endangered species. Today, global warming is the greatest threat to it. Rising temperatures are causing the ice to melt earlier each year, preventing bears from building up sufficient fat reserves and forcing them to fast for longer periods.
In Western Hudson Bay, the ice now breaks up three weeks earlier than it did in the early 1970s. Starvation has already reduced the survival rate of cubs and young bears, and made bears of all ages less healthy. Within the next 35 to 50 years, a decline in the overall polar bear population of more than 30% is expected, and within 100 years they may become extirpated from most of their geographic range.
