Out of all the bear species that have been discovered and documented, polar bears are probably among the most well-known and popular ones. Polar bears, if not living in captivity, can mainly be seen living atop the sea ice found all over the Arctic Ocean which they use as their habitat as well as a platform to get their food.
Through the high-fat content provided by their prey, which is mostly seals, polar bears hold the record for being the largest bear species found on Earth.
Since they spend most of their lives swimming and hunting seals in the water, they are considered marine mammals as well. These majestic creatures, however, are not as common as we think.
They are now considered as a threatened species that only have between 20,000 to 25,000 members left, which could greatly be attributed to the worsening climate change that is directly affecting their icy habitats.
Even if that is the case, polar bears, just like other animals, are guided by their instincts in finding a safer place or location, even if it means traveling tens and hundreds of kilometers just to ensure their survival in an event that is known as migration.
Animal migration, in general, had baffled and fascinated scientists and researchers for as long as the recorded history goes. In this article, we will mainly be talking about all the known facts about polar bear migration.
Why do polar bears migrate?
When the season changes and approaches summer, the ice platforms that the polar bears use in hunting their main prey, which are either ringed or bearded seals, start to melt.
Without the ice platforms, polar bears will no longer have a ground to stand on which prevents them from having easy access to their prey. This is considered as a critical period of a polar bear’s life since the amount of fat it has dictates whether the bear could survive the months between summer and fall.
When the ice in the Arctic Ocean starts to melt, this signals the polar bears to start their migration towards reforming ice packs with plenty of available food.
However, some polar bears have also been documented to migrate onshore, which is the case for the bears found in Hudson Bay, Canada. These bears are also considered to be the most observed and studied group of polar bears.
In the case of the Hudson Bay polar bears, they have been documented to undergo the phenomenon that scientists describe as a sort of “walking hibernation” where they will consume their fat deposit and lose around 1 kilogram each day.
This is since, unlike other bears, polar bears do not go through hibernation and only the females have been observed to undergo hibernation-like state when they give birth.
On land, they will have to survive until the ice in the Hudson Bay starts to reform and within this period, not all of the polar bears will survive. Many will most likely perish, especially those who have not stored enough fat to survive the months ahead. Although polar bears can also eat the food found on land, they will most likely lose more energy than they can gain by doing so.
Where do polar bears migrate?
Polar bears have been observed to follow a North to South migration pattern and have been seen on the ice packs found all over the Arctic Ocean.
Different groups undergo different migration patterns, but the Hudson Bay polar bears can be seen to gather around Churchill in Canada, which is considered to be the “polar bear capital of the world”, once the ice starts to reform during the start of Autumn.
Polar bear tracks have also been found as far north as the North Pole, however, since there is little to no food around these areas, scientists believe that the bears do not frequent these locations.
Polar bears are also frequent visitors to locations with heavy ice packs such as Norway, Newfoundland, Labrador, as well as the Bering Sea.
When do polar bears migrate?
Some groups of polar bears had been observed to have migrated all year round to reach food-rich areas. However, the well-documented Hudson Bay polar bears usually migrate during summer months, typically starting in June and ending in September.
Once the ice starts to reform during Autumn, which usually starts in September, bears start their migration towards the ice packs again.
Impacts of climate change on polar bear migration patterns or habits
In recent years, polar bears have been observed to have become thinner and more vulnerable to death more than ever and this is mainly attributed to the exponentially increasing effect of climate change.
Due to the intensifying climate change, the ice packs around the arctic sea are starting to melt at a terrifying rate and reforms later than usual. These factors have caused a disturbance in the migration process of the polar bears and are increasing their mortality rate as well.
In Hudson Bay, where the most well-documented polar bear migration happens, it was observed that they are now spending thirty more days onshore as compared to what was observed 30 years ago.
As established earlier, the main diet of polar bears is seals, and if they spend more time on land, they would lose more energy that ultimately results in their deaths.
Not only that, due to the increasing rate of global warming, their prey is getting farther and farther away from them, further leading to their starvation.
Scientists are even suggesting that by the next century, polar bears will officially become extinct if the current rate of global warming continues.