Polar bears do not hibernate like other species of bear, this is because they spend winter on the sea ice hunting seals and building up their fat reserves for summer which is spent on the mainland or small archipelagos in the arctic.
However, female polar bears do enter a hibernation-like state. They will enter the den around October with cubs being born around 60 days later, although they will remain in the den for a total of 7-8 months until the cubs can leave.
During this time, they remain in a reduced metabolic state, they don’t eat, drink, urinate, or defecate to save energy.
- https://polarguidebook.com/facts-about-polar-bears/
