Mike and I came across the Elephant Seal Viewpoint in San Simeon, California. The elephant seals rebounded from near-extinction, being hunted for their oils, they first re-established colonies on the islands off the shore of Baja California and California. When these rookeries became too crowded, they began colonizing mainland beaches.
In order to dive so deep and stay down in the cold ocean so long, the elephant seals have had to make a number of adaptations. One of these adaptations is that during dives the flow of blood to their skin and extremities is limited – sending blood mostly to their brain and core organs. In order to get healthy new skin, elephant seals need to spend about a month on the beach so that their blood can circulate continuously to the skin without an excessive loss of body heat.
This annual month long process of shedding their entire outer layer of skin and hair is called a catastrophic molt.
They began coming here in 1990. The Piedras Blancas Rookery was populated from San Miguel Island, San Nicolas Island, and Ano Nuevo. Elephant seals like large sandy beaches that do not have a significant human presence. The rocky areas in the shallow waters provide the weaned pups some protection from breakers while they are learning to swim. The kelp forests, which are not far off shore, and the shallowness of the sea bed could help the seals avoid predation since shark attacks are more common in deeper water.
Their bodies are designed to keep warm in cold water. Sand flipping helps them keep cool on land by acting as a sunscreen. In addition, they sometimes can be seen flipping sand under stressful conditions.
People frequently think the seals on the beach are dead because they aren’t moving or breathing. Actually, they are just conserving energy. During the time they are ashore they are fasting. They rely on their stored fat to meet their water and energy needs, so their bodies are programmed to rest as much as possible while on land.
In addition, they practice a form of apnea; a breath-holding state. During apnea, their heart rate decreases. Apnea can last as little as 8 minutes in weaners and up to 25 minutes in adult males.
The large males, those with the big noses that give elephant seals their names, are only on the beach in July-August to molt and in December-March for the birthing and mating seasons. They spend most of their lives at sea foraging off the coast of Alaska in the Aleutian Islands.
Large males are 14 to 16 feet in length and weigh 3,000 to 5,000 pounds. Adult females are 9 to 12 feet in length and weigh between 900 and 1800 pounds. Pups are 3 to 4 feet long and weigh 60 to 80 pounds at birth.
Adult and sub-adult males spend 8 to 9 months at sea. Females and juveniles of both sexes spend 10 months at sea.
They dive for 20 minutes to over an hour, surface and breathe for 2 to 4 minutes and then dive again. They do this 24 hours a day, 7 days a week. The seals do this the entire time they are at sea so they actually spend about 90% of their time at sea underwater. They normally dive 1,000 to 2,000 feet but can go down as deep as 5,000 feet where they feed on small bio-luminescent creatures such as squid and lanternfish.
The elephant seals do not eat while they are at the rookery. They live off their blubber, relying on it to provide water and energy. While they are ashore for birthing and breeding, the females will lose 30 to 40 percent of their body mass. Large males, who fast for 3 months during the breeding season, will also lose about a third of their body weight.
Weaners practice at night to learn to swim and dive in preparation for the dark of the ocean depths in which they will feed.
November: Sub adult males haul out on the beach. Mature males begin arriving at the end of the month.
• December: Bulls continue to return. Females arrive. The first birth is usually mid-month.
• January: Females continue to arrive. Peak of births is usually the last half of the month.
• February: Births continue. The peak of the mating is around Valentine’s Day. More females begin leaving.
• March: Last adults leave. Weaned pups teach themselves how to swim.
Mothers spend about one month with their pup. Their milk is among the richest of any mammal, averaging 55% fat. At the start of lactation, the fat content is lower and the water content higher. By the end of lactation, the fat content reaches 65% and has the consistency of mayonnaise. Human milk is 2 to 4% fat, cow’s milk 3 to 6%. The pups go from 60 to 80 pounds at birth to 250 to 330 pounds at weaning, quadrupling their birth weight.
Comments