Thank you for signing up to our email!

Now, before you leave, do you want to make a seal's day?

Orphaned Harbor Seal Pup Heyerdahl Ventures Out on His Own

With no mother in sight, a newborn harbor seal pup is brought to The Marine Mammal Center for special care until he’s able to survive on his own.

April 8, 2016

Photo © Rob Cala

The cries of a hungry harbor seal pup are a heart-wrenching “mah! mah!” as if he is calling out for his mother by name. Right now at The Marine Mammal Center you’re likely to hear a whole chorus during feeding time as we’re caring for more than 40 harbor seal pups—twice as many as we typically do this time of year.

Our experts believe this could be due to the strong El Niño storms we’ve seen along the California coast over the last few months. These storms can cause mother seals and their pups to get swept out to sea or separated and unable to reunite. A small pup that heads out in search of mom may find he isn’t quite strong enough to swim past the breakers.

Photo © Rob Cala

One such pup, a current patient, shares a name with Norwegian adventurer Thor Heyerdahl, who is most notable for his Kon-Tiki expedition across the Pacific Ocean in a hand-built raft. But Heyerdahl the seal pup wasn’t quite as successful when he ventured out to sea on his own.

San Mateo County Park Ranger Rob Cala caught these stunning photos of Heyerdahl struggling in the water and alone on the beach at Fitzgerald Marine Reserve, a known harbor seal haul-out area. When our volunteers were called to the scene to check on the pup, they noted that he was active and vocal—signs of good health.

Photo © Rob Cala

Because we know that harbor seal moms often leave their pups on the beach while they forage for food nearby, our rescue team decided to hold off and check on Heyerdahl again in the morning, to give him a chance to reunite with his mom.

But the next day, little Heyerdahl was still near the same spot and there was no evidence of an adult seal nearby. Knowing he couldn’t survive on his own, our rescue volunteers picked him up and brought him to our hospital on the morning of March 18.

Photo © Rob Cala

During Heyerdahl’s admit exam, our veterinarians noted that he still had some of his lanugo coat, or baby fur, as well as part of his umbilical cord still attached—indicating that he was likely just a few days old.

Heyerdahl was started on a four-times-a-day regimen of electrolyte fluids mixed with a special milk formula to get him fully hydrated and stabilized. A standard course of vitamins and antibiotics were added to help treat any infections and boost his fragile newborn immune system.

Without the antibodies from his mother’s milk, Heyerdahl and pups like him are at higher risk of illness. That’s why all of our harbor seal pup patients are cared for by a separate team of volunteers in an isolated area of the hospital that doesn’t share water pipes or filtration systems with our other pens and pools.

Photo © Rob Cala

These volunteers are specially trained to keep the environment as sterile as possible and avoid cross-contamination with our other patients, such as sea lions and fur seals, which may be carrying parasites or viruses that could easily sicken these vulnerable pups.

After being in our care for three weeks, Heyerdahl is now transitioning from drinking milk formula to eating whole fish, just as he would in the wild. But without his mother to teach him how, he needs the help of our volunteers, who coax him into chasing fish around the pool by tying string on a herring and dragging it through the water.

Once Heyerdahl is able to chase fish on his own and compete with his fellow penmates, he’ll be well on his way to a second chance at life in the wild.

Photo © Rob Cala

Leave Seals Be

Spring is pupping season along the California coast as mother seals and sea lions give birth. This year, we are rescuing unusual numbers of California sea lions, northern elephant seals and harbor seals like Heyerdahl.

If you see a seal or sea lion pup on a beach that looks sick or injured, please resist the urge to pick it up or get too close. The best thing you can do for these animals is to leave seals be and call our 24-hour rescue hotline at 415-289-SEAL (7325) so that our experts can assess the situation and rescue the animal if needed.

Photo © Rob Cala

You Can Make a Difference

During this unusually busy spring season, pups like Heyerdahl are eating through more than 1,000 pounds of fish a day. At a cost of about $1 per pound of fish, those food bills really add up!

You can make a real difference for newborn pups like Heyerdahl by supporting our Dollar-a-Pound campaign with your gift today.


Stay in touch! Learn more about our pinniped patients and follow their fascinating stories.

Sign up for updates from The Marine Mammal Center.



Learn about: Pacific harbor seals

Learn how important it is to Leave Seals Be

Learn how you can: Get Involved to Help Marine Mammals!


Printer Friendly

Print-Friendly Version



COVID Response

Focusing on safety in our core work.

Adopt a Seal

Your symbolic adoption helps our patients thrive.

Our Commitment

Expanding work on social and environmental equity.