No less than a month sooner than in additional northerly areas of the Arctic, the primary identified feminine with new cubs-of-the-year has been reported on the ocean ice looking for seals in Western Hudson Bay. Bear in mind this when the cries of “early” breakup of sea ice on Hudson Bay come in the summertime: these WH bears routinely get a head begin on spring feeding that different bears don’t get.
Bear O4 simply left her den & made it to the ocean ice (bear closest to coast): possible along with her cubs out to hunt. She must rebuild depleted fats depots for subsequent summer time.
Right here is the map he included, on which I’ve circled “Bear 04”:
As I’ve said beforehand, in most areas of the Arctic, December is when polar bear cubs are born, though in southern areas (like Western and Southern Hudson Bay), some could also be born in late November and within the far, far north, just a few could also be born as late as early February.
The precise date of start for polar bear cubs is commonly back-calculated from after they emerge with their moms within the spring at about 3 months of age, as a result of they’re born nicely away from our prying eyes at nighttime of the Arctic winter, deep inside a snow or soil den dug for that function. So our data of the true dates of start in varied areas is restricted.
Now we have some proof from native Canadian hunters previous to 1968, when it was each authorized and customary observe in Canada for Inuit to hunt bears of their dens (Van de Velde et al. 2003), and from just a few scientific analysis expeditions (Amstrup and Gardner 1994; Harington 1968; Ramsay and Stirling 1988).
It seems that the feminine proven on Derocher’s map (“04”) certainly should have given start in late November with a purpose to have cubs sufficiently old to be nicely offshore by 4 March. In different phrases, the household had been possible out of their den, on the brink of transfer out, near the center of February (presuming this feminine certainly has cubs along with her, which has not been confirmed).
This feminine’s location in early February:
For comparability, the video under provides a dialogue of polar bear den research in Svalbard, produced by Polar Bears Worldwide in 2021. They map they present signifies how a lot additional north Svalbard is than Western Hudson Bay.
Remember the fact that since sea ice situations have modified round Svalbard (about 2003), most pregnant females make their dens on the ocean ice or in Franz Josef Land. And regardless of pessimistic prognostications for the longer term, Svalbard bears (together with grownup females) have been doing very nicely regardless of a lot much less sea ice (Lippold et al. 2019:988), as Jon Aars actually admits within the video.
References
Amstrup, S.C. and Gardner, C. 1994. Polar bear maternity denning within the Beaufort Sea. Journal of Wildlife Administration 58:1-10. http://www.jstor.org/uncover/10.2307/3809542
Harington, R. C. 1968. Denning habits of the polar bear (Ursus maritimus Phipps). Canadian Wildlife Service Report Collection No. 5., Ottawa
Lippold, A., Bourgeon, S., Aars, J., Andersen, M., Polder, A., Lyche, J.L., Bytingsvik, J., Jenssen, B.M., Derocher, A.E., Welker, J.M. and Routti, H. 2019. Temporal developments of persistent natural pollution in Barents Sea polar bears (Ursus maritimus) in relation to adjustments in feeding habits and physique situation. Environmental Science and Technology 53(2):984-995.
Ramsay, M. A. and Stirling, I. 1988. Reproductive biology and ecology of feminine polar bears (Ursus maritimus). Journal of Zoology London 214:601-634. http://onlinelibrary.wiley.com/doi/10.1111/j.1469-7998.1988.tb03762.x/summary
Van de Velde (OMI), F., Stirling, I. and Richardson, E. 2003. Polar bear (Ursus maritimus) denning within the space of the Simpson Peninsula, Nunavut. Arctic 56:191-197. http://arctic.synergiesprairies.ca/arctic/index.php/arctic/article/view/615
