Males are born slightly larger than females. 2.Polar bear cubs are born small and helpless, with their eyes closed. 3.The fur is very fine at birth, making the cubs look hairless. F. Care of young. Female polar bears have four mammary glands.
Mothers nurse their cubs in a sitting position, or lying down on their side or back.
During their first few weeks of life, polar bear cubs nurse most of the time and stay close to their mother to keep warm. For the next three or four months the cubs nurse as often as six times a day. The length and number of nursings gradually decreases as the cubs grow older. Mother polar bears nurse their cubs for as long as 30 months. Some cubs stop nursing as young as 18 months of age, but remain with their mothers for survival until they are 30 months old.