* Insulation: The fat layer acts as a natural insulator, trapping heat and preventing the bear from losing body heat in the frigid Arctic environment. This is crucial for their survival, as they spend a significant amount of time in icy water or on the sea ice.
* Energy reserve: Fat is a highly efficient form of energy storage. During the lean months when food is scarce, polar bears rely on their fat reserves to sustain them.
* Buoyancy: The fat layer helps polar bears stay buoyant in water. This is important for swimming and hunting seals, their primary food source.
* Protection: The fat layer also provides some protection from predators and the harsh elements of the Arctic. It acts as a cushion against bumps and scrapes, and helps to insulate the bear from the cold.
Overall, the thick layer of fat under the skin is a critical adaptation that allows polar bears to thrive in the challenging conditions of the Arctic.