Females come into season around 16 days after their pups are born. They leave the pup to mate, before returning to the sea, the embryo is then held in suspension for 3 months before developing. Pups are born white, from September to December, after a 9 month gestation period. They weigh approximately 30lbs at birth and should be 100lbs after 16 days due to their mother's very rich milk. The mothers feed their pups for 2 - 3 weeks.
Seals eat molluscs, crustaceans, squid, octopus and bottom living fish.
In diving, seals use a process known as 'bradycardia ', a reduction in heart beats both in number of beats and strength, as it submerges. This happens immediately on diving, unlike cetaceans where the process is a gradual one. Also, all air is expelled from the lungs on diving and what little air remains does so in the cartliage supported and non absorptive part of the lungs, therefore they are not at risk of 'the bends'. Strong laryngeal muscles prevent water entering the trachea when the seal opens it's mouth under water. Some seals are capable of staying underwater for over an hour without access to oxygen - the maximum for a human being 2.5 minutes.