Deadly Bird Flu Outbreak Hits California Elephant Seals

H5N1 virus confirmed in seals at Año Nuevo State Park, prompting park closures and warnings about approaching the animals.

Published on Feb. 26, 2026

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The H5N1 bird flu virus that has devastated seal populations in South America has now been confirmed in elephant seals at California's Año Nuevo State Park. This marks the first detected outbreak of the virus among marine mammals in the state. Park officials have canceled seal-watching tours and closed public viewing areas as a precaution to prevent the spread of the disease.

Why it matters

The worldwide bird flu outbreak that began in 2020 has led to the deaths of millions of domesticated birds and spread to wildlife around the world. Seals and sea lions appear to be particularly vulnerable to the H5N1 virus, which has caused the deaths of thousands of these animals in South America in recent years. This outbreak in California raises concerns about the potential impact on the state's wildlife and the need for continued monitoring and prevention efforts.

The details

Researchers from UC Davis and UC Santa Cruz announced the detection of the H5N1 virus in elephant seals at Año Nuevo State Park. This is the first time the virus has been confirmed in marine mammals in California. The park has canceled its popular seal-watching tours for the remainder of the breeding season as a precaution, and officials are urging the public to avoid approaching the seals and keep pets away from the animals.

  • On February 19 and 20, sick and dead animals were spotted at Año Nuevo State Park.
  • On February 26, 2026, researchers announced the detection of the H5N1 virus in the elephant seals.

The players

Año Nuevo State Park

A California state park located about 90 minutes south of San Francisco, known for its large population of elephant seals that come to the area each winter to breed and give birth.

University of California-Santa Cruz

A public research university that collaborated with UC Davis on the detection and announcement of the H5N1 virus in the California elephant seals.

University of California-Davis

A public research university that collaborated with UC Santa Cruz on the detection and announcement of the H5N1 virus in the California elephant seals.

Jordan Burgess

The deputy district superintendent of the California Department of Parks and Recreation, who announced the closure of public viewing areas and cancellation of seal-watching tours at Año Nuevo State Park.

Christine Johnson

The director of the Institute for Pandemic Insights at UC Davis' Weill School of Veterinary Medicine, who commented on the quick detection of the outbreak due to researchers being on high alert.

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What they’re saying

“We're definitely not panicking about human exposure at this point, but rather trying to ensure the health of the seals and people in general.”

— Jordan Burgess, Deputy District Superintendent, California Department of Parks and Recreation

“After sick and dead animals were spotted on Feb. 19 and 20, researchers collected samples for testing at the California Animal Health and Food Safety Laboratory System. The screening showed the animals were infected with HPAI H5N1 virus.”

— Christine Johnson, Director, Institute for Pandemic Insights, UC Davis Weill School of Veterinary Medicine

What’s next

Officials hope the closure of public viewing areas and cancellation of tours at Año Nuevo State Park will help prevent the spread of the H5N1 virus among the elephant seal population. The California Department of Parks and Recreation will continue to monitor the situation and provide updates on when the park may reopen for seal-watching activities.

The takeaway

This outbreak in California highlights the ongoing threat of zoonotic diseases like bird flu, which can spread from wild animals to humans. It underscores the importance of vigilant monitoring, early detection, and proactive measures to protect both wildlife and public health in the face of emerging infectious disease challenges.