CU of polar bear cubs keeping close to mother as they walk up slope. MS of polar bear mother and cubs returning to den, climbing over snowy ridge, mother and one cub sliding into den hole, second cub hesitating on edge before sliding in headfirst. HA MLS of cubs climbing out of den, mother looking on, one cub accidentally sliding back into den, its head emerging a few seconds later; family beginning to trek away from den, cubs playfully clinging to leg of mother. HA LS of polar bear and two cubs trotting across snowfield. (41557)