Elephant seals are the largest pinniped (seal or sea lion) in the Monterey Bay. They breed in large numbers every winter at Ano Nuevo State Reserve in San Mateo County.
During the breeding season, massive, four thousand pound bulls fight. The winners of these fights, the most dominant bulls, have primary breeding rights over the females.
These impressive battles usually only last for a brief moment, but in rare cases can last for over an hour. Fights are usually initiated by trumpeting, then followed by chest batting, head butting, or biting. Fights can be bloody, and although rare, bite wounds to the skull can be fatal.
Females arrive pregnant in December or January, giving birth to their pups about 4-5 days after hitting on shore.
After giving birth, females nurse their pups for thirty days. Nursing pups consume milk that is 55% fat. In contrast most people drink skim or low fat milk. Whole milk, which is 4% fat, seems a bit thick for most people’s taste. Elephant seal pups are guzzling milk that is the consistency of mayonnaise. After just 11 days of nursing, pups double in weight.
By the end of March, most of the bulls and females have returned to the open ocean, leaving only the weaners, weaned pups, on shore.