The harp seal gives birth to pups with a white woolly coat called lanugo.
Newborn harp seal pups are famously whitecoats because their thick white lanugo provides camouflage on snow and sea ice. The coat is not permanent: pups molt it after a few weeks and develop a darker, spotted juvenile pelage. During this short nursing period, the mother provides exceptionally rich milk that supports rapid growth.
The white coat can cause confusion with adult coloration. Adult harp seals are silver-gray with dark markings, including the pattern that gives the species its common name. Harp seals breed in large colonies on seasonal pack ice in the North Atlantic and Arctic regions.