By Nat Hab Expedition Chief Katrina Rosen
Initially, polar bears had been believed to be one massive household that interacted with each other and aimlessly wandered atop the world. Nonetheless, the notion that setting off in an unknown path will result in meals, mates and shelter is both credulous or proof of outstanding bravery, as demonstrated by early Arctic explorers.
Some polar bears by no means step onto land, residing their complete lives on the ice. They’re as marine as belugas or sea lions, actually embodying their identify, Ursus Maritimus. But, right here we’re, close to the southernmost vary of the polar bears. The bay is unfrozen, and this carnivorous maritime animal roams the land.
You may marvel, “Why don’t they go additional north?” The fact is that house is the place the guts is. These massive nomads lead lives of constancy.
Most of us like to journey—heading south or snowboarding within the winter, staying by a lake in the summertime. Touring is a shared ardour, however finally, we all the time return house. It’s acquainted, comfy and a spot the place we have now shelter, meals and associates. The identical is true for all polar bears.
Whereas Hudson Bay is frozen, the polar bears from the east and west might intermix, however as soon as the spring breakup arrives, they continue to be extremely devoted to their summer time house ranges. Because the final ice melts within the southeast nook of the bay, our western polar bears steadily make their approach towards Churchill. This huge predator is aware of that is the place the ice will type once more first. The pregnant females know they are going to discover secure denning areas inside sixty miles of the ocean. They know this from their upbringing. Luckily for us, this congregation of bears is close by of a comparatively trendy city.
Canada might home 60% of the polar bear inhabitants, however probably the most particular ones are simply miles from our Polar Rover. We’re within the midst of the Western Hudson Bay subpopulation, numbering round 850. These are the world’s most well-known polar bears. As we traverse the tundra, contemplate this as Hollywood Boulevard, Manitoba—our bears are the celebrities.
Not simply because they’re as cute as Channing Tatum, however this Western Hudson Bay inhabitants has contributed considerably to our understanding of polar bear biology and ecology greater than every other subpopulation. The reason being easy—learning bears right here is cheaper than in distant, greater latitudes, particularly these contrasting with the summer time terrain.
One of many first duties of the biologists was to develop secure methods for capturing and tagging particular person bears. They had been marked with ear tags and customized identification tattoos on their internal lips. Via this technique and the recapturing of the identical bears in subsequent years, together with returned tags from Inuit hunters, they demonstrated the polar bears’ seasonal constancy.
Shores of Hudson Bay, photographed by Nat Hab Expedition Chief © Eddy Savage
Whatever the distances they traveled to search out seals within the winter, they all the time returned to the Manitoba coast in summer time. From this information, biologists recognized nineteen subpopulations of polar bears, every residing inside their ranges. This information enabled the event of acceptable administration and conservation methods for every space.
Let me paint an image, for little has modified for the reason that Seventies. Simply north of Churchill, a predominantly flat esker stays from the final main glaciation. Past it, a barren land of rolling rock, arctic vegetation, and permafrost extends into the shallow tidal flats of Hudson Bay. The Churchill River empties to the west of a pointed headland and to the east of a distinguished spit. It’s a bleak, windy place with no geographical aid or cowl. Right here, in 1976, an statement tower was constructed to review the polar bears arriving in massive numbers each fall.
The researchers noticed subadult males sparing and subadult females steering away from interactions. Largely, they discovered that the bears had been comparatively inactive. Throughout autumn, when the bay is devoid of ice, polar bears eat little or no, metabolizing saved vitality reserves slowly till they return to the ice.
As soon as radio collars had been developed, they match nicely solely on females, because the males’ necks had been bigger than their heads. The collars confirmed a variety variance between 1,150 and 94,000 sq. miles, proving that the polar bears returned to the identical space. Researchers might now monitor how far pregnant females moved inland, research the distinctive peat moss dens, and start to unravel the focus of dens close to right here, a subject we are going to delve into later.
The dates of the bay’s ice breakup and refreeze, recorded by researchers, supplied priceless proof in later years of the detrimental results early ice disappearance has on polar bears.
Additionally, in 1976, the Churchill Northern Examine Middle was based. Nonetheless operational year-round right now, it helps scientific analysis, contributing considerably to our data of polar bears.
Just lately, developments have allowed male polar bears to be tracked utilizing battery-operated ear tags. On the Polar Bears Worldwide web site, we are able to watch stay monitoring of polar bears each winter whereas they’re on the ice.
The seasonal motion of our Western Hudson Bay bears introduced the understanding that was craved. By inserting themselves in the appropriate location, the bears got here to the scientists. A query that is still mystifying and continues to be below analysis is: How precisely do polar bears navigate?
After I was 13, I used to be misplaced in a single day within the forest. I by no means anticipated to be so distant, however I knew I’d finally discover my approach again house. When the solar rose, I stored it on my left shoulder and trekked out for hours in the identical path. Polar bears are extremely clever. Whether or not they navigate by the solar, stars, prevailing winds, or their sense of odor, which is much superior to our understanding, they know the place they wish to go—again to the world the place they had been born and raised by their moms.
If nothing else, this place is the polar bear scientific analysis capital of the world as a result of house is the place the guts is.
