Impact of climate change on polar bears
Smaller sea ice season means less time for polar bears to hunt
In the southern range of polar bears, for example in Hudson Bay and James Bay of Canada, sea ice is now melting earlier in the spring and forming later in the autumn.
The time bears have on the ice is their best season – hunting seals and fish is easy, and they restore their body fat and fitness. But this crucial time for storing up energy for the warm season when there is less ice and little available food is becoming dangerously limited.
As the periods without food lengthen, the overall body condition of polar bears declines.
This is particularly serious for bears that are pregnant or nursing young, and for the cubs themselves. In Hudson Bay, scientists have found the main cause of death in cubs to be either lack of food or lack of fat on nursing mothers.