Classification
Seals make up the families Otariidae, Odobenidae, and Phocidae of the order Pinnipedia. The southern elephant seal is classified as Mirounga leonina.
Breeding Season
The elephant seal breeding season begins in December, when the first males arrive. From fourteen to sixteen feet long and weighing up to 2 1/2 tons, these huge bulls engage in violent battles to establish dominance. The successful bulls do much of the breeding, with most of the duty falling on the "alpha" bull at the top of the social ladder. In late December, the females begin to arrive and form "harems" on the beaches of the. Much smaller than the males, they average ten to twelve feet in length and weigh 1,200 to 2,000 pounds. Three to six days after she arrives, the female gives birth to the pup that was conceived the previous year. Normally only one pup is born to each female, and she nurses for 25 to 28 days.
Molting
Pinnipeds, like other mammals, must replace old skin and hair. Most animals shed hairs year-around, but elephant seals do it all at once. The molting process is so abrupt in the elephant seal that it is called a catastrophic molt. During the spring and summer months, elephant seals return to Año Nuevo for their annual molts.
Feeding
At sea, elephant seals typically dive 20 minutes to a depth of 1,000 to 2,000 feet in search of food: rays, skates, rat fish, squid, and small sharks. The maximum recorded depth is 5,015 feet by a male in 1991. The females eat nothing while they are giving birth, nursing, and mating, and the males go without food for up to three months at that time. They are preyed upon by killer whales and sharks.
Development
Females give birth for the first time at an average age of 3-4 and have an average life expectancy of about 20 years. Males are mature at five years, don't reach high rank until 8 with prime breeding years between 9-12. Males have a life expectancy of 14 years.