Watch the third episode of Some Ocean Optimism featuring questions from the audience. Then keep reading to learn even more about this fascinating species, one of our most common patients.
September 22, 2020
What is the difference between northern elephant seals and southern elephant seals?
Northern elephant seals, the species we care for, range from Mexico to Alaska. Southern elephant seals are on the opposite side of the world and live in the sub-Antarctic and Antarctic waters. Southern elephant seals are also bigger, with males close to 20 feet long and 8,800 pounds compared to male northern elephant seals at 15 feet and 5,000 pounds.
Where are they most commonly found here on the West Coast?
There are only three places in the Northern Hemisphere to view elephant seals and all are within driving distance of the San Francisco Bay Area. Piedras Blancas in San Simeon, Año Nuevo State Park in Pescadero and Point Reyes National Seashore are all great places to view wild elephant seals.
Do elephant seals visit areas outside of California, such as Washington state?
Northern elephant seals are found in the North Pacific from Baja California, Mexico, to the Gulf of Alaska and Aleutian Islands. They are primarily found in California in January and February. During molting periods, they can be found on other beaches.
Do northern elephant seals share their beaches with other pinnipeds?
Elephant seals can share beaches with other pinnipeds, but we don’t often see this happen because elephant seals spend 250-300 days a year out at sea. So they aren’t on land as often as harbor seals or sea lions. Additionally, the short time they do spend on land is to breed or molt, making them particularly territorial or aggressive, so other pinnipeds don’t like hanging around.
What’s the status of the northern elephant seal population? Are they endangered?
The northern elephant seal is a conservation success story! After whales became scarce, elephant seals were hunted to the brink of extinction, primarily for their blubber, which was used for lamp oil. By 1910, it is estimated that there were less than 100 elephant seals left. Today, the northern elephant seal population is approximately 150,000, and is probably near the size it was before they were over-hunted.
What’s the average lifespan of an elephant seal?
There is a notable difference in lifespan between male and female northern elephant seals. Females generally live for about 19 years, while males only live for about 13 years.
What are the primary dangers pups face?
Sadly, some pups are accidentally trampled by large adult males. Generally, females with pups will try to stay on the outer boundaries of male territories while caring for their pups. The primary danger for pups, however, is becoming separated from their moms prematurely during this crucial time of growth. Pups that are separated too soon quickly become malnourished and require rescue.
Ecology and Biology
When do the pups start taking care of themselves?
Pups are typically weaned, or are no longer reliant on their mother’s milk, by 28 days after being born. At this point, pups will learn to swim, dive, hunt and take care of themselves on their own.
Why do mother elephant seals leave their babies to fend for themselves so early?
While the 28 days elephant seal moms spend with their pups doesn’t seem long, every day the pup drinks mom’s milk, they gain 8 pounds. That type of growth takes a lot out of the mom, and she will lose close to 600 pounds during that month. After giving all of her reserves to the pup, she heads out to find food to recover. At that point, the pup should have all the fat reserves needed to learn to swim and hunt on their own.
How long is a female elephant seal pregnant?
Elephant seals have a gestation of seven months. Because they only come on land twice a year (and see males once a year), they developed a reproductive strategy called delayed implantation. Females will typically mate in January/February, but the fertilized egg doesn’t attach to the uterus wall for another four months.
How do elephant seals dive so deep and stay underwater so long?
Elephant seals can dive over 5,000 feet and stay underwater for two hours at a time. To accomplish this feat, they slow their heartbeat from close to 120 beats per minute to just 1 to 2 beats per minute, so they use less oxygen. Second, they stop blood flow to different parts of their body they’re not using, saving it for essential things like their brain, heart and sometimes their stomach if they’re eating a good meal. When they dive to 5,000 feet to eat, they also tend to take a bit of a nap, shutting down half of their brain at a time in order to rest.
How do they see and find food when they are diving deep?
Their huge eyes help absorb more light at dark depths so they can see better. Their sensitive whiskers sense vibrations so even if they can’t see, they can sense prey, including squid and fish like herring, which we feed our baby elephant seals at the Center.
What do elephant seals drink?
Apart from nursing pups, elephant seals don’t actually need to drink anything because they get all the hydration they need from their food. Water is produced internally from their food during the process of metabolic breakdown.
What do elephant seals eat?
Elephant seals are opportunistic feeders, eating mostly small schooling fish, such as anchovies, herring and sardines, as well as squid, octopus and small sharks. At the Center, we feed them sustainable Pacific herring from Alaska.
Why are seals so fat?
Elephant seals and many other marine mammals have evolved to have a special kind of fat called blubber, which is thicker than regular fat and contains more blood vessels. Blubber is better at storing energy, insulating the body and increasing buoyancy—all incredibly beneficial adaptations for deep-diving marine mammals that live in the harsh ocean environment.
Do they hear sound? If so, how?
Yes, elephant seals do hear sound. It might be hard to see, but elephant seals do have open ear holes on the sides of their head rather than external ear flaps like sea lions.
How good is their sense of smell?
You might imagine with those big noses comes a good sense of smell—and you’d be right! Moms and babies can actually recognize each other from their smell. As soon as pups are born, they will go nose-to-nose to smell and talk to their mothers so they‘ll remember what they smell and sound like!
What do male elephant seals use their nose for and why do they have such long noses?
A male elephant seal will develop his long nose, also called a proboscis, at about 5 to 7 years old. While it may look silly, it’s a very helpful adaptation. All that extra skin acts like a megaphone to warn off other males from the many females they are mating with as part of their harem.
How do elephant seals compare in size to other pinnipeds?
The northern elephant seal is the second largest seal in the world, after the southern elephant seal.
Do the whiskers on top of their head serve a special purpose?
All seals and sea lions have whiskers, or vibrissae, that serve as an extra sense for them. The whiskers can pick up little vibrations in the water and help identify what’s around them, even if they can’t see.
Do seals sneeze?
Yes, they do sneeze.
Do elephant seals have good memories like elephants?
Intelligence and memory tests can only be done in captive settings, and there are almost no elephant seals in captivity, making these types of research projects limited compared to species like elephants, chimpanzees and dogs. However, elephant seals go on one of the longest migrations of any mammal, swimming from California to Alaska twice a year, and always return to the same beach to rest and give birth, so that might indicate they have a pretty good memory.
Why do elephant seals fling sand on themselves while other seals don’t?
An elephant seal’s body is designed to stay warm when they spend 250-300 days a year in the water. All of that blubber helps them in the cold waters off the California coast, but being on land can sometimes get too hot for them, so flipping sand on themselves helps cool them off.
Rescue and Patient Care
Have adult elephant seals been reported to have Otostrongylus circumlitus infections?
We tend to see young elephant seals at the hospital suffering from Otostronglyus, a lungworm parasite. This parasite’s life cycle is unique. Scientists believe it starts in harbor seals, where it normally doesn’t cause many problems, and the parasite’s eggs are passed in their feces, which is then eaten by fish. Animals that eat those fish can now get the lungworm parasite. Young elephant seals and harbor seals both tend to eat along the coast in shallow water, so that may be why young elephant seals often get it. Adult elephant seals feed out in the open ocean, so they shouldn’t be exposed to the same fish and should see very little, if any, of this parasite. It doesn’t mean adult elephant seals can’t get it, but their different feeding style means adults should be safer than pups.
Why do so many of these adorable creatures end up in your care each year? Did the pandemic change the number rescued?
Elephant seals are one of the most common patients we rescue each year, mostly young, baby elephant seals in the springtime that get separated from their mothers too early. During the 2020 pandemic, we saw a relatively low number, partially because the weather was nicer, and there were fewer storms that could wash pups off the beaches prematurely. It’s also possible that some weren’t spotted due to fewer people on the beach or limited access to certain areas prevented us from rescuing them.
How many elephant seals do you treat each year?
Elephant seals are one of the most common patients we rescue. It varies each year, but during our busiest years we might rescue more than 200 elephant seals.
How far away should people stay if they see an elephant seal on the beach?
If you see an elephant seal, or any seal, on the beach, be sure to keep at least 50 feet away or far enough away that the seal is not reacting to your presence. This is for both your own and the seal’s safety. If the elephant seal looks sick or injured, call our 24-hour rescue hotline 415-289-SEAL.
If someone is diving and an elephant seal comes up to check them out, what's the best thing to do?
Diving is a great way to view marine life and ecosystems. Sometimes you may be approached by marine mammals while diving, and it’s important to remember they are still wild animals and can have unpredictable behavior, even if they seem curious and playful. For your safety and theirs, it is important to maintain a safe distance. Additionally, they’re protected by the Marine Mammal Protection Act, which states that it’s illegal to swim with, ride, pet, touch or attempt to interact with marine mammals in the wild.