Pagophilic behavior: mother seal suckling pup on the ice

Phocidae (true seals) of the Northwest Atlantic exhibit a variety of reproductive patterns associated with different breeding substrates. Terrestrial breeding species have relatively long lactation (24 days in harbor seals (Phoca vitulina)), whereas species such as Grey Seals (Halichoerus) and Harp Seals (Pagophilus) that breed on pack ice have brief but intense lactation. Hooded seals (Cystophora cristata) have the briefest lactation known for any mammal, four days, but the milk is of high quality and the young spend a large part of the day nursing (Perry et. al. 1995. J. Mammal 76:22)