The bears’ sea-ice habitat has been disappearing at an alarming rate, with the far north of the planet warming up to four times faster than the rest of the world.
The sea ice has become less thick and is breaking up earlier in the spring and freezing later in the autumn.
The bears rely on the ice to be able to forage for seals, move and reproduce.
The ice pack in the Hudson Bay has decreased by nearly 50% in summer since the 1980s, according to the US National Snow and Ice Data Center.
A report published two years ago in the journal Nature Climate Change suggested this trend could lead to the near-extinction of the bay’s polar bears, noting there were 1,200 on its western shores in the 1980s.