It is well known that the polar bear, Ursis maritimus, lives in the arctic. What may not be as well known is how close the arctic and it’s polar bear residents are to us. There are 19 sub-populations of polar bears spread throughout 5 different countries; Canada, Alaska, Norway Greenland and Russia. Canada is home to approximately 60% of the world’s number of polar bears with roughly 1000 bears living within the Southern Hudson bay population. The Southern Hudson bay population encompasses much of the Ontario and Quebec coast lines, the entire James Bay as well as southern and eastern portions of the Hudson Bay.
As well as polar bears, First Nation’s people have lived along the Hudson and James Bay coastlines for thousands of years. Polar bears represent an integral part of their cultural history and subsistence lifestyle. Hunting of polar bears still continues today but is regulated by individual provinces and territories.
To put all of that in perspective, The Cochrane Polar Bear Habitat is only 250kms south of James Bay. Cochrane lies on the 49th parallel and it’s climate is considered to be sub-arctic. For the people of Cochrane, the winters can be long and harsh but for it’s three resident male polar bears Ganuk, Henry and Inukshuk, this climate is perfect.
The Southern Hudson Bay population of polar bears will experience dramatic seasonal change throughout the year. The winter can be bitterly cold, with temperatures dropping to -50 degrees celsius. The ocean freezes, arctic winds blow and polar bears travel great distances in search of their main prey, seals. In the Spring, temperatures are still cold enough for the ocean to remain frozen but the days begin to get longer. It is assumed that the extended hours of sunlight influences hormone development, which signals the males to start searching for females to mate with and it also marks the start of seal pup season. Polar bears make the most of this easy abundance of food and will go into a state of ‘hyperphagia’ meaning they will gorge themselves with the aim of consuming as many calories as possible. Fattening up in the spring is especially important for the bears of the southern Hudson Bay population which will spend the summer and early fall on land as the ice melts and retreats north. Without the sea ice, polar bears have no platform on which to hunt, forcing them to fast until the ice returns in the late fall. During this period of fasting, polar bears aim to expend as little energy as possible by greatly reducing their activity rate. They may consume bird eggs, kelp and berries, but can only survive off a high fat marine diet. By late fall, temperatures are once again beginning to drop and the bears congregate on coast in anticipation for the freeze up of the bay and end of their fasting period. While the bears are congregating, the males will become more active and social with other male bears. Bears of all sex and age classes have also been seen eating an increased amount of kelp and vegetation, which may assist the digestive system after eating minimally for 3-4 months. Wrestling and sparring between males is common, which is thought to strengthen their muscles after the inactivity of the summer. These behaviours also help to develop a rough hierarchy which will be in place when competing over food or females. Once the ice has formed enough for the bears to travel on they will begin this yearly cycle once again.
As The Cochrane Polar Bear Habitat is located so close to the polar bear’s natural home range, similar seasonal changes in body condition and behaviour can be seen in our bears. To learn more about our bears and these changes, tune in to tomorrow’s instalment where we will take a closer look at Ganuk, Henry and Inukshuk.