One of the largest and most well known sanctuary for elephant seals is right here on the central coast at Piedras Blancas elephant seal sanctuary north of San Simeon, California.

Elephant seals, Mirounga angustirostris, are true seals, or earless seals, members of the pinniped suborder. What marvelous creatures they are: huge blubbery males with the pendulous noses that give these beasts their name; winsome females whose faces seem to be etched with a permanent smile; and endearing plump babies with big brown eyes.

In the 1880's northern elephant seals were thought to be extinct, harvested by shore whalers and sealers for their blubber. The oil obtained from elephant seals is second in quality only to the sperm whale. A small group of between 20-100 elephant seals that bred on Guadalupe Island, off Baja California, survived the ravages of the seal hunts. Protected first by Mexico and later by the United States, they have steadily expanded their range. Today they are protected from hunting and harassment by the Marine Mammal Protection Act of 1972. The total population estimate for northern elephant seals in 2006 is around 170,000.

The breeding season begins in late November when mature bulls begin to arrive and fight to determine dominance. The females start arriving in the middle of December and continue to arrive until the middle of February. The first birth is around Christmas, but most births usually occur during the last two weeks of January. The females remain on the beach for about five weeks from the time they come ashore. Amazingly, the males are on the beach for up to 100 days. The seals are fasting while they are on land, and both males and females lose about 1/3 of their body weight during the breeding season.

Elephant seals form harems, in which the dominant, or alpha, male is surrounded by a group of females. On the periphery of the harem, the beta bulls wait in hopes of an opportunity to mate. They assist the alpha bull in keeping away the less dominant males. Fights between males can be bloody affairs in which the combatants rear up and slam their bodies against each other, slashing with their large canine teeth. However, not all confrontations end in battle. Rearing up on their hindquarters, throwing back their heads, showing off the size of their noses and bellowing threats is enough to intimidate most challengers. When battles do occur, it is rarely to the death.

The rookery is a very noisy place during the breeding season as males bellow threat vocalizations, pups squawk to be fed, and females squabble with each other over prime location and pups. Gargles, grunts, snorts, belches, bleats, whimpers, squeaks, squeals, and the male trumpeting combine to create the elephant seal symphony of sound.

The pups are usually born within 4-5 days of the female's arrival, and weigh between 60-80 pounds. They nurse for 24-28 days on the richest milk in the mammal world. Mating occurs during the last 2-3 days of nursing. The peak of mating activity is around Valentine's Day. Pups are weaned when the mother abruptly departs for sea. The weaned pups, dubbed "weaners," have quadrupled their birthweight and are nice and plump. They will lose about one-third of their weight during the "weaner fast," the 8-10 weeks they remain at the rookery, teaching themselves how to swim, before taking off on their first foraging trip.

While elephant seals are at sea in search of food they dive to incredible depths. Typically they dive between 1000-2000 feet, but the record is over 5000 feet. The average length of dive is 20 minutes, but they can dive for an hour or longer. When they resurface they only spend 2-3 minutes before diving again - and they continue this diving pattern 24 hours a day. Male and female elephant seals are believed to feed on different prey. The female diet is primarily squid and the male diet is more varied, comprised of small sharks, rays and other bottom-dwelling fish. In their search for food the males travel along the continental shelf to the Gulf of Alaska. The females tend to head north and west into more open ocean. Elephant seals make this migration twice a year, also coming back to the rookery to molt in late spring and the summer time. These two migrations total up to eight to twelve thousand miles of travel annually.

Human beings shed hair and skin all the time, but elephant seals go through a catastrophic molt, in which the entire layer of epidermis with the hairs attached is sloughed off in one concentrated time. The reason for this abrupt molt is that while at sea they spend most of their time in cold deep water. As part of the dive process the blood is diverted away from the skin. This helps them conserve energy and avoid losing body heat. By coming up on land to molt the blood can be circulated to the skin so a new layer of epidermis and hair can be grown.

Elephant seals are sexually dimorphic: the males are much larger than the females and only the males develop the long noses and chest shield. Females grow to 9-12 feet and weigh between 900-1800 pounds. Males grow to 14-16 feet long and weigh in at 3000-5000 pounds, or more. Female elephant seals give birth for the first time around 4 years old, though the range is between 2-6 years of age. Females are considered physically mature at age 6 and can live to a maximum of 20 years. Males enter puberty around 4 years of age, at which time the nose starts to grow. The nose is a secondary sexual characteristic, like a man's beard, and can reach the astonishing length of 2 feet. Males reach physical maturity around 9 years old. Prime breeding age is 9-12, and they can live to a maximum of 14 years.

What is an elephant seal? A deep-sea diver, a long distance traveler, an animal that fasts for long periods of time, elephant seals are extraordinary. They come together on land to give birth, mate, and molt but at sea they are solitary. Tremendous demands are placed on their bodies. The more you learn about these animals the more you will say WOW!
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The northern elephant seals come to the rookery twice a year - once in the late spring and summer for approximately one month to molt and once in the fall or winter to rest if they are young or to give birth and breed if they are mature. The rest of the year, ten months of the year for most of the animals, they are at sea. While at sea they are solitary and spend 80% to 90% of their time deep under water. They dive routinely to 1000 to 2000 feet (300 to 700 meters) staying down typically for periods of one-half hour before returning to the surface to breathe for 2-3 minutes. Individual seals have been known to dive to over 5000 feet and to stay down as long as 2 hours. This behavior continues, uninterrupted by visits to land or longer periods on the surface, 24 hours a day for periods of several months.

The male seals typically forage for food on the continental shelf from Oregon to as far west as the Aleutian Islands - 3000 miles from the Central Coast of California. Their diet consists primarily of bottom dwelling fish - hakes, rays, small sharks - and squid. The density of food on the shelf is much higher than at intermediate depths so that they are able to obtain the approximately 100 pounds of fish per day that their great size requires. Feeding over the shelf, however, puts them relatively near the coast, a region most heavily populated by their major predator, the great white shark, but the need for food in large quantity justifies the greater risk. Their two foraging trips are approximately equal in length at four months.

The female seals, who do not grow so large as the adult males and who, as adults, spend two more months at sea each year, forage in deeper water well south of the continental shelf. There the ocean is so deep that they cannot feed off the bottom. They have a diet of squid and fish, and range widely over a considerable area. Unlike the males, the two foraging trips of adult females are of quite different length - approximately two months between weaning their pup and returning to molt and eight months between the end of the molt and birthing. Only during this longer second period is the female nourishing a fetus as well as herself.

The foraging patterns noted above are not always followed. One tracked seal from Ano Nuevo was observed to spend all of her foraging time in the neighborhood of Monterey Bay, and at least one female has been seen near the Alaskan continental shelf.
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Elephant seals have made many adaptations that allow then to dive deeply and go for extended periods of time without eating .

Diving adaptations: All mammals, carry oxygen in their blood (in hemoglobin, the complex molecule in the red blood cells) and in their muscles (in myoglobin, another complex molecule). Elephant seals have twice the blood volume , three times as much hemoglobin, and much more myoglobin than land mammals of the same size. Thus they live off the oxygen stored in the blood and the muscle for the time they are below the surface and, most remarkably, are able to recharge these complex molecules during the few minutes they are at the surface. In addition to a large and rich blood supply, the seals also have a special region in their circulatory system for storing carbon-dioxide laden, oxygen depleted blood.

As part of the dive reflex blood is diverted away from the skin to the core organs, thus saving energy that would otherwise go into re-warming cooled blood. The reason elephant seals come on the beach to molt is to allow the blood to circulate to the skin so new hair and tissue can receive the nourishment required for growth.

Adaptations to their neurological system, that are not clearly understood, allow elephant seals to dive to depths where the pressure is great enough to make most mammals go into involuntary synapse firing or seizures.

Thermoregulation: Elephant seals have a thick layer of blubber between their skin and their vital organs to help keep them warm at sea. Their problem is keeping cool on land. The blubber is not present in two places on the seal; the flippers and the "arm pits" of the front flippers . Indeed, a common method of cooling on the beach is to lift a front fin and let the breeze cool the uninsulated skin in the arm pit. Two other common means of cooling off are flipping sand to cover their bodies or simply moving down to the waters edge where it's cooler.

The blood vessels in the flippers are grouped together in such a way that the arteries and veins help maintain a steady body temperature. Therefore at sea, in a process referred to as countercurrent heat exchange, the cooler blood returning toward the heart is warmed by the warm blood heading toward the extremities, further reducing heat loss and maximizing energy. Countercurrent heat exchange is also used in the reverse to provide cooling of reproductive organs which must be kept at lower temperature.

Moisture and Energy Conservation: Elephant seals are extremely energy efficient mammals: conserving energy, hence oxygen, at sea and conserving energy, hence food resources in the blubber, and body moisture on land.

Being neutrally buoyant elephant seals are able to swim efficiently by only having to sweep their rear flippers back and forth a few times then gliding down for a distance before more propulsion is needed. On the beach, seals will often go into apnea (sleeping without breathing) for periods of eight to thirty minutes, depending on their age. As a result, they are often taken for dead by visitors. The normal position for elephant seal nostrils is closed so when they snort them open to breathe there is a discharge of white mucous, creating the misimpression that they are ill.

Elephant seals can remain in the rookery for one to three months without food or water. A mother elephant seal comes on the beach, gives birth to a 60-80 pound pup and nurses it for four weeks without consuming either food or water! Males remain at the rookery without eating for three months during the breeding season. Pups live off their blubber for about two and a half months before leaving on their first delete foraging trip. They accomplish this by metabolizing their blubber into nourishment and moisture.
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Why do they flip sand?
With all that blubber, their bodies are designed to keep warm in cold water. Sand flipping helps them keep cool on land by acting as a sun screen. In addition, they sometimes can be seen flipping sand under stressful conditions.

Where are the big males?
The large males, those with the big noses that give elephant seals their name, are only on the beach in July-August to molt and in December-March for the birthing and breeding seasons. They spend most of the year foraging off the Aleutian Islands of Alaska.

Who are their predators?
Great white sharks and killer whales (Orcas) prey on elephant seals as well as other marine life. Great whites attack from below with most attacks occurring near the surface. If the bite is superficial, the seal may escape. Sometimes you can see e-seals with scars showing they had a near-miss encounter with a shark. Predation by orcas has been documented less frequently.

Are there sharks offshore?
Yes. Great white sharks are found in temperate coastal waters world-wide including off the Central Coast. Seals with fresh shark bites or shark bitten otter carcasses are seen sometimes along this coast but it isn't believed that there is a large population of great whites in the area. At this time, they are not specifically targeting this rookery. Ano Nuevo, near Santa Cruz, has been a rookery since the early 50s and the sharks do seem to target it for part of the each year.

Are elephant seals here all year?
Yes, there are always some elephant seals here although they become very sparse in August and September. Individually, each seal is normally here twice a year for approximately one month each time with the exception of the adult males who are here for one month in summer and three months in December-March.

Why do adult males have a large nose?
The large nose is a secondary sexual characteristic indicating physical and sexual maturity. Large body size, large nose, and a deep booming voice sometimes serve to intimidate challengers thus avoiding energy depleting fights.

Are females pregnant for 11 months?
Technically yes. However, there is a delayed implantation of the embryo: the fertilized egg divides a few times and then just floats in the uterus. This allows the mother, who has lost over a third of her body weight feeding her recently delivered baby and herself with metabolized blubber, to regains some of that weight before the new fetus begins to grow. After three to four months, the blastocyst attaches to the uterine wall and begins growing again. Some experts believe that the hormones directing implantation are activated at the end of the molt. The eleven month gestation also serves to synchronize the births to the same time every year.

How long do they live?
Males can live to 14; females to 20. But only a few live that long. Only one in seven pups lives to 4 years old.

Why do they molt at the rookery?
Skin cells, of elephant seals or humans, take a real beating and need to be replaced. For humans, the process is continuous throughout the year - we shed and grow about nine pounds of skin cells each year. Because growing new skin cells requires circulating blood outside the blubber layer, elephant seals grow their new skin during a few weeks each year on the beach, where the loss of body heat is much less than would occur in the ocean.

What do they eat?
Females, who eat in the deep ocean, eat primarily squid. Males who forage over the continental shelf eat bottom dwelling species such as ratfish, hagfish, Pacific hake, rays, skates, and small sharks. Many of the things they eat are bioluminescent. They also swallow their prey whole and digest it in about six hours.

How much time do they spend at sea?
Adult and sub-adult males spend eight to nine months at sea; females and juveniles of both sexes spend ten months. Their dives last from twenty minuets to over an hour with only two to four minutes at the surface between dives. They do this their entire time at sea so they spend about 90% of their time at sea under water.

How deep do they dive?
The normally dive 1,000 to 2,000 feet but can go as deep as 5,000 feet. When they dive, they swim only for the first one hundred feet and coast for the remainder.

How do they stay down so long?
Elephant seals have a number of unusual adaptations which allow them to dive so deep and stay under so long. They must exhale before they dive to avoid the bends (an affliction caused by the absorption of gas by the cells at high pressure) so all the oxygen they have is that in the blood (in hemoglobin in the red blood cells) and in the muscle (in myoglobin). Their blood volume is twice that of a land mammal their size and that blood is 50% richer in hemoglobin.
In addition, they undergo significant physiological changes as part of their diving reflex. Their heart beat slows from 55-120 beats per minute to 4-15 beats per minute. They are able to divert the flow of blood from their extremities and restrict it to just their vital internal organs. These changes allow them to use less oxygen.

Do mothers have just one pup? If twining occurs in northern elephant seals at all, it is very rare. It is documented in southern elephant seals, close relatives. As the mother loses one-third of her body weight while on the beach giving birth to a single pup and nursing it to 300 pounds, it is clear that twining would not be advantageous.

Do big males fight to the death? Rarely. As beach dominance is established in December and during the breeding season in February, bulls often battle each other. These confrontations are often bloody but rarely result in serious injury. The neck and chest area of a large bull is protected by a calloused shield and a thick layer of blubber. Fights can last from just a few minutes to half an hour, depending upon how evenly matched the bulls are. On occasion, a broken jaw or blinded eye from such fights may eventually lead to death because they would impair foraging. Almost all mortality occurs at sea.
The younger males, often seen sparring either on the beach or in the shallow waters off shore, are learning how to fight but for them, as for other young male mammals, this is playing rather than fighting and animals are very seldom injured in this activity.

Why did they start coming to this rookery? As the elephant seals rebounded from near-extinction, they first established colonies on the islands offshore Baja California and California. As these rookeries became crowded, they began colonizing mainland beaches. They began coming here in 1990, populated initially by seals from San Miguel Island, San Nicolas Island, and Ano Nuevo. We still see seals at this rookery who were born elsewhere.
Elephant seals like large sandy beaches that do not have a significant human presence. They prefer south facing beaches with protection from northwest storms. The shallow waters protected from breakers provide areas where the weaned pups can learn to swim and older males can spar. The kelp forest not far off shore and the rapid drop-off of the sea bed protect the seals from predators.

Are they dead? Why do they just lie there?
People often think that seals on the beach are dead because they are not moving or breathing. They will often stop breathing and dramatically lower their heart rate - as they do routinely at sea - for periods of a few minutes to half an hour. That apnea and their general inactivity are ways of conserving energy. During the time they are on shore, which occurs only in the rookery, they are fasting and relying on their stored fat to meet their water and energy needs.

Do mothers meet up with their babies the next year?
Seals usually return to the beach where they were born but we don't know if they recognize each other. It does not appear so.

How fast do they normally move in water?
It is estimated that they swim at speeds of 10 to 15 mph. En route to the feeding grounds, they cover around 60 miles a day, diving and foraging as they go.

How fast can they move on land?
While they seldom move rapidly at all on land, when they perceive a threat to themselves or the harem, they can move on soft sand faster than most humans.

Do big males hurt the babies?
It is very unusual for a big male to deliberately hurt a baby. However, babies can be accidentally injured or killed if they are in the way when a large male is defending his harem from another bull.

Do they go out in the ocean to eat?
They do not eat while at the rookery. Except for an occasional relocation within the rookery, and males sparring or fighting in the shallow water just off shore, they do not go in the water at all. They rely on metabolized blubber for energy and water.

How many females are in a harem?
The number of females in a harem varies according to the topography of the beach. There can be as few as 10 and as many as 50 surrounding an alpha male. He provides protection from the amorous attention of other males.

How old are they when they begin reproducing?
Males enter puberty around 4 years of age but they don't reach their full physical growth until they are around 9. At that time they are big enough to become serious contenders for beach territory. Some males never win enough fights to ever be able to breed. Prime breeding age is between 9 and 12.
Females normally begin reproducing around age 4 although some begin as young as 2 or delay to as late as 6. They become physically mature and stop growing in length at age 6.

Do they come back to the same rookery each year?
It appears that elephant seals generally return to the beaches where they were born. However, overcrowding or failure to successfully wean a pup can prompt them to move to another rookery.

How big are they?
Large males are 14 to 16 feet in length and weigh between 3,000 and 5,000 pounds. Adult females are 9 to 12 feet in length and weigh between 900 and 1,800 pounds. Pups are 3 to 4 feet long and weigh 60 to 80 pounds at birth.
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Information Courtesy of Friends of the Elephant Seals