The most important bear on this planet and the Arctic’s prime predator, polar bears are an imposing image of endurance. The polar bear may be discovered wandering the Arctic in Canada, America, Russia, Norway and Greenland. Its Latin identify, Ursus maritimus, means “sea bear,” which is sensible for a beast that spends a lot of its life in, round or on the ocean, predominantly on the ocean ice.
There are six distinct polar bear populations alongside the polar basin’s southern rim, every influenced by a unique sample of ice motion: the Canadian Arctic, Northern Alaska, Western Alaska and Wrangell Island, Svalbard and Franz Josef Land, Central Siberia and Greenland.
A separate group of bears lives close to Hudson Bay in Canada; that is essentially the most southerly inhabitants and one we love to go to on our Nat Hab journeys. The yearly cycles of freezing and melting ice drastically affect the place these polar bears reside and when. Sadly, rising temperatures from local weather change are forcing the bears to shift their pure annual cycle, with much less time out there every year to spend trying to find seals on prime of frozen sea ice.
A polar bear’s vary is huge, and in the course of the course of a yr, one bear might journey greater than 20,000 sq. miles inside a normal area—however that kind of migration requires a robust provide of nourishment. What are they doing as they cowl that a lot floor? How do they gas up for the journey? And the way is local weather change affecting that pure cycle?
Let’s get to know these magnificent creatures that the Arctic’s Indigenous Inupiaq name the Nanuuq and be taught a bit extra about a yr within the lifetime of a typical Hudson Bay polar bear.
Winter
Pregnant feminine polar bears typically spend the winter hibernating, gestating, giving start to and nursing their new cubs in order that they’re robust sufficient to exit the den within the spring. The snow den protects the defenseless newborns from the frigid chilly, they usually keep inside it till late March or April.
Feminine polar bears give start each two to 3 years and have round 5 litters throughout their lifetime—one of many lowest mammalian reproductive charges.
Males and non-pregnant females don’t hibernate, as an alternative spending the winter out on the ice surviving off their fats reserves after gorging on seals within the autumn. Their fur and 4 inches of blubber defend them from the tough chilly, and the thick sea ice gives a stable platform from which they’ll proceed to hunt seals. The soles of their large (as much as 12 inches in diameter) paws act as large snowshoes and are lined with dense pads of fur that supply nice traction on the ice.
Due to their massive stomachs, polar bears can devour as much as 150 kilos in a single sitting, which helps them take full benefit of any meals discovered. They should devour at the very least one seal each 5 or 6 days to protect their physique weight. The polar bear’s fur is water-repellent and manufactured from distinctive hole hairs that allow the channeling of photo voltaic power on to the polar bear’s black pores and skin beneath, serving to them keep heat. This permits the polar bear to outlive within the Arctic, the place temperatures usually fall to -22˚F in the course of the winter.
Spring
By spring, new cubs often weigh about 20–25 kilos and are on the brink of depart the den. Playtime within the spring is a perfect approach for the little cubs to apply the abilities they might want to survive, similar to looking, combating and speaking with different bears.
Throughout the lengthy months of denning, pregnant and nursing females might not eat for as much as eight months, all whereas having to fulfill the big power calls for of gestation and lactation. Suffice it to say they depart the den hungry!
In the meantime, huge chunks of ice known as “floes” carry the male polar bears towards the shore in spring, the place they emerge onto land to breed (and search for any remaining meals). A feminine polar bear mates for the primary time when she is round 5 or 6 years outdated. Breeding happens on the ice pack between late March and mid-July. Females go into estrus for roughly three weeks, at which era the males compete fiercely to pursue them. Dominant males might achieve mating with a number of females in a season, however they solely stick round for a few week after mating.
When a feminine polar bear turns into pregnant, the embryo divides quite a lot of instances, then curiously pauses its growth and free-floats till it lastly implants into the uterine lining later in September.
In later spring, as summer time approaches, the bears begin a protracted journey northward, trekking 800 to 900 miles alongside the coast to seal-hunting grounds. On land, these bears have an opportunity at scavenging meals: a whale, seal or fish carcass washed up on shore or the stays of an animal hunted by one other predator. They stroll alongside the western shore till reaching the northwestern coast as soon as once more, the place they’ll wait patiently for the ice to freeze.
Summer season
Polar bears within the Canadian Arctic will typically select to summer time on the coast to search for meals as an alternative of heading north with the retreating ice. Throughout the summer time in Hudson Bay, bears meander inland and attempt to take care of the nice and cozy temperatures by sheltering in dugouts deep sufficient to achieve permafrost. They appear to love to remain close to the coast, however they’ve been discovered as much as 100 miles inland in the summertime months.
© Eddy Savage
Within the heat summer time months, the often 100% carnivorous polar bears will scarf down just about something edible, together with eggs, reindeer, carrion and even crops and berries. Even with this vary of meals, polar bears drastically drop weight in summer time and early autumn, subsisting totally on stockpiled fats. They’re just too large to obtain a lot power from small morsels like Arctic hare or fish.
Feminine polar bears attain a most weight of roughly 660 kilos, with males coming in on common from 1,100 to 1,300 kilos. The largest recorded polar bear weighed a whopping 2,210 kilos—not a straightforward determine to take care of in the summertime on paltry berries and eggs. And because the seal-hunting season continues to shorten in a warming Arctic (ice is freezing a lot later within the yr and melting a lot earlier), hungry polar bears might battle to retain sufficient fats shops to outlive via the lengthy summer time seal quick.
Autumn
Round October, the planet’s largest focus of polar bears gathers alongside Hudson Bay, ready for the ice to kind so their seal-hunting season can start. By mid-October, between 600 and 1,000 bears congregate alongside a 100-mile stretch of coast between the Churchill and Nelson rivers (with an abundance round Cape Churchill).
When the ice lastly turns into thick sufficient to resist their weight, the bears eagerly head out onto the frozen sea to prey upon seals. Polar bears feed primarily on ringed seals, however in addition they hunt bearded, harp and hooded seals, in addition to the occasional walrus. Polar bears have glorious eyesight and listening to, and their noses are so delicate that they’ll detect a seal greater than 20 miles away. In truth, researchers in Alaska have watched male polar bears journey very targeted in a straight line for as much as 40 miles to achieve prey they’ve detected.
© Brad Josephs
Utilizing their jagged again enamel and canines bigger than these of a grizzly, polar bears eat the fats and pores and skin of their prey and depart the meat for Arctic foxes, with whom they share a mutualistic symbiotic relationship.
Pregnant females assemble their maternity dens in deep snow drifts on land in autumn. A soon-to-be mother has to make sure the snow is deep sufficient for her and her cubs, but secure sufficient that it received’t collapse on prime of her. Previously, many feminine polar bears constructed dens on the ocean ice, however the warming local weather has made it tough to seek out high quality locations to den on the ice, so bears have more and more been making dens on land on coastal and river bluffs, barrier islands and different areas the place snow accumulates. Cubs are born blind between November and early January and weigh solely about 1.5 kilos at start.
Polar Bears: Underneath Menace
Due to the continued lack of their sea ice habitat from rising temperatures, polar bears have been listed as a threatened species within the U.S. below the Endangered Species Act in Might of 2008. The survival of polar bears and the safety of their habitat are pressing points for each us at Nat Hab and our companions at World Wildlife Fund.
As local weather change forces polar bears to spend extra time onshore, they arrive involved extra typically with Arctic communities, which all too typically ends badly for both the people or the bears (or each). In Russia, Alaska, Greenland and Canada, WWF has responded to human-bear battle with quite a lot of community-led initiatives. WWF and its companions are additionally working to catalyze the event of latest applied sciences that can make polar bear analysis cheaper, much less invasive and ship extra helpful knowledge to assist assist their safety.
What’s the Greatest Time of Yr to See Polar Bears within the Wild?
By far the most effective locations to view polar bears within the wild is alongside Hudson Bay’s western shore within the autumn. Hudson Bay is a big physique of water, about double the scale of Texas, that covers 850 miles from north to south and 650 miles east to west. Polar bears congregate close to the shore right here as they await Hudson Bay to freeze, once they rush onto the ice to hunt and fatten up as a lot as they’ll earlier than winter, which means right now they’re comparatively lively and out and about.
© Lianne Thompson
Simply two polar bear tour operators in Churchill maintain extremely coveted permits to entry the complete Churchill Wildlife Administration Space—the place the very best polar bear viewing happens—and we’re proud to say certainly one of them. With this, not solely can we present our vacationers with the very best wildlife-viewing expertise, however we’re in a position to journey in snug custom-built Polar Rovers that may navigate the tundra and the distant Hudson Bay shoreline to provide us entry to prime bear viewing.
What’s extra, due to our shut partnership with WWF, Nat Hab and our Arctic Expedition Leaders have entry to the most recent analysis and knowledge on polar bear habitat and conservation initiatives—which advantages each the bears and our visitors!
Prepared to fulfill the King of the Arctic for your self? Think about becoming a member of us on a Churchill Polar Bears journey quickly!
