* Polar bears: They have the thickest fur of any bear species, with a dense undercoat and long, hollow guard hairs that trap air for insulation.
* Kodiak bears: These brown bears are known for their massive size and thick fur, which helps them survive the cold Alaskan climate.
* Brown bears: While not as thick as polar bear fur, brown bears have a thick, dense coat that helps them stay warm in cold environments.
* American black bears: They also have thick fur, especially during the winter months when they grow a thicker undercoat for insulation.
It's important to remember that even bears with thick fur can be found in various climates. For instance, brown bears live in both cold and temperate environments.