National Zoo’s oldest sea lion, who ‘always kept keepers on their toes,’ dies at 19

Summer, the National Zoo’s oldest sea lion, died June 27 at the age of 19, the Zoo announced Friday. (Courtesy Smithsonian’s National Zoo and Conservation Biology Institute)

Summer, the oldest sea lion at Smithsonian’s National Zoo, was humanely euthanized on June 27, the zoo announced Friday. She was 19.

Keepers with the zoo’s American Trail exhibit noticed that Summer, a female California sea lion, was lethargic and not eating on June 26, according to a news release from the zoo. The zoo’s veterinary team gave her fluids, antibiotics and steroids, but her condition had not gotten any better by the next day.

The veterinary team conducted a follow-up exam, which showed signs of kidney failure, as well as potential heart disease. That’s when the zoo’s veterinary and animal care teams “made the difficult decision” to euthanize Summer due to concerns about her quality of life, according to the release.

According to a necropsy performed by zoo pathologists, Summer had abnormalities in her kidneys and fluid in her lungs and trachea. The zoo said a full pathology report will come out in the next few weeks.

Summer was a California girl, born on the beaches of Malibu on June 17, 2005, according to the zoo. She was abandoned by her mother shortly after birth and taken in by wildlife rehabilitators for hand-rearing.

Summer made her D.C. debut in 2006, when she came to the zoo with another female sea lion named Calli.

“If Summer didn’t want to do something, she would let you know,” said Ashley Graham, assistant curator of American Trail. “She always kept keepers on their toes.”

According to the zoo, while she could have an attitude with keepers, Summer was “particularly gentle” with the younger sea lions. She never had pups of her own, but was like a “second mom” to Calli’s little ones and was always the first adult to be introduced to juveniles, keepers said.

The median life expectancy for California sea lions in human care is 20 to 25 years, according to the news release.

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Kate Corliss

Kate Corliss is a Digital Writer/Editor for She is a senior studying journalism at American University and serves as the Campus Life Editor for the student newspaper, The Eagle.

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