What do you know about Polar Bears? They are carnivorous mammals that live along the shores and on sea ice in the Arctic circle. They are found in the northern parts of Alaska, Canada, Russia, Greenland, and some northern islands owned by Norway, such as Svalbard. They weigh upto 1600 pounds.
So, what do they eat? They primarily eat seals. During the winters, when sea ice forms on the ocean, polar bears venture out onto the ice to hunt for seals. They rest at seal’s breathing holes waiting for a seal to peak out of the water. They also hunt by swimming beneath the ice!
What is sea ice? Sea ice is frozen seawater that floats on the ocean surface, forming and melting with the polar seasons.
Is it true polar bears go through periods of feast and famine? Polar bears hunt during the winters and build up storage that sees them through the warmer months. Their bodies have a flabby layer of fat, which can be up to 3.4 inches thick. This fat keeps them warm, but also acts as an energy store. They draw on these energy reserves to make it through lean summer months on land. This is why bears are used to fasting for months!
Why have polar bears been listed as vulnerable to extinction by conservation authorities? For years, scientists have been worried about polar bear populations. Climate change is making it harder for polar bears to hunt for seals. Warmer temperatures are causing sea ice to break and melt earlier. As the Arctic sea ice shrinks polar bears are unable to hunt for seals. They are forced to roam for long distances or on to shore, where they struggle to find food or feed their cubs. They scavenge for less nutritious food on land such as berries, kelp, whale carcasses, bird eggs, and even reindeer. None of these food items are sustainable substitutes in the long-term as seal fat is really the only food with high enough energy content to keep polar bears going.
How many polar bears exist today? Scientists estimate that there are fewer than 26,000 left, spread out across 19 different subpopulations today.
Why are we discussing them? A recent study actually confirms scientist’s fears. It predicts when, where and how polar bear populations are likely to disappear. The study warns if humans fail to reduce greenhouse gas emissions, most polar bear populations will disappear by 2100.
What did the study find? This dramatic loss of sea ice is causing bear populations in some parts of the Arctic to go longer and longer without food. Scientists studied how long bears could fast before it affected their cubs and their own survival. They realised that long periods of starvation will affect bear cubs first. Next female bears and cubs are most vulnerable. Malnourished females are unable to produce enough milk to nurse their cubs and this impacts their survival. The next group are adult bears and single females.
The study predicts that the inability to feed cubs will impact polar bear populations as early as 2040, leading to local extinctions.
Af the end the study forecasts that under the current climate scenario, where green house emissions continue to rise, nearly all polar bears in the Arctic may struggle to survive by 2100!
Is there any good news? Yes there is some hope. The study says if humans are able to cut global emissions, there is still a chance that polar bears might survive in some regions beyond the end of this century. So, polar bears are not completely doomed if we change our behaviour!