Beloved Sea Lion at National Zoo Dies Unexpectedly

Calli, a 17-year-old California sea lion, is remembered by zoo staff as a good mother and ambassador for her species

A sea lion looks into the camera
Calli moves around on land. Rebecca Sturniolo / Smithsonian’s National Zoo

Calli, one of the Smithsonian’s National Zoo’s most beloved California sea lions, died on September 7, zoo officials said yesterday in a statement.

The 17-year-old animal was a longtime resident of the zoo, taken in at a young age after her mother died when she was a newborn.

“She was like the golden retriever of the sea lions,” Rebecca Sturniolo, assistant curator for the American Trail at the National Zoo, tells Smithsonian magazine. “She was just really calm and accepting of new people… She was also the one that we would generally do our demonstration with, because she was so reliable.”

Earlier this year, Calli became pregnant, but an ultrasound in July revealed a miscarriage. On September 6, the zoo’s veterinarians anesthetized the sea lion and confirmed that she was no longer pregnant. The exam didn’t show anything abnormal in her abdomen or reproductive tract, per the statement, and for the rest of the evening, she behaved as though nothing was wrong.

The next day, she continued to act normally, but when the keepers went to check on her in the afternoon, as was routine, they found her deceased. An examination by zoo pathologists found lesions in her gastrointestinal tract and respiratory system.

It will likely be a few weeks before the zoo gets additional test results back, as James Steeil, the zoo’s supervisory veterinary medical officer, tells Smithsonian magazine in an email.

“The lesions she had in her lungs and GI tract are not something that is common in sea lions and likely is not related to her fetal loss, but [that] cannot be 100 percent ruled out,” he writes. “When we do get the completed necropsy, hopefully that will help shed some light on her illness and determine if any changes to how we work and treat these animals will occur.”

An unexpected death like this is “always hard,” Sturniolo says. “I take solace in knowing that we gave her a great life while she was here. And she was loved by a lot of people.”

A California sea lion in front of water
Calli the California sea lion Rebecca Sturniolo / Smithsonian’s National Zoo

Calli was born in the wild on California’s Little Corona Beach in 2005. But after her birth, passers by noticed her mother appeared to be ill, and they called the nearby Pacific Marine Mammal Center, which picked up both Calli and her mom. Within no more than a couple of days, the mother, who was sick from domoic acid poisoning, died.

“It's thought that domoic acid poisoning can reach really high levels when there's these great big algae blooms, mostly referred to as ‘red tides.’ And that can be caused by global warming and agricultural runoff and pollution,” Sturniolo says. When sea lions eat crustaceans, shellfish or fish that have fed on large amounts of algae, they can get amnesic shellfish poisoning, which can be fatal.

Newly orphaned, Calli had to be bottle-fed and hand-raised by humans. In 2006, the young sea lion was transferred to the National Zoo, along with another female named Summer, who is still on exhibit.

When she was young, Calli would play with a small white tub given to the sea lions for enrichment, swimming around the habitat with it upside-down on her head, per the statement. These days, Calli’s pup Celia enjoys interacting with visitors through the glass—moving back and forth between the windows to find the most entertaining guests to play with, Sturniolo says.

As she grew up, Calli’s interest shifted to caring for her young. The first pup she had was actually born at the Pittsburgh Zoo, when she was temporarily there during renovation of the D.C. habitat. In 2016, Calli gave birth to a second pup named Catalina, who was the first sea lion born at the National Zoo in 32 years. Three years later, she birthed Celia. Sturniolo remembers Calli as a good mother—she was “really protective of her youngsters, very attentive, taught them to swim [and] would play with them on exhibit,” she says.

In the wild, California sea lions are abundant, in part due to safeguards from the Marine Mammal Protection Act, which makes it illegal to harass, capture, feed or kill these animals. Their range stretches from Baja, Mexico, to Vancouver Island in Canada. Sea lions still face a host of threats, though, including entanglement in fishing gear, diseases and toxins, such as those that sickened Calli’s mother.

Calli’s story, Sturniolo says, was a reminder to zoo visitors that human actions have an effect on sea lions.

“I think it was impactful for folks to hear that an animal actually needed our help because of something that we've done as a society,” she says. “We make choices every day that can negatively or positively impact animals out in the wild.”