Deadly bird flu found in California elephant seals for the first time - Los Angeles Times

Los Angeles Times

by Susanne Rust

February 25, 2026

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California’s elephant seals have been confirmed as the first in North America to be infected with the H5N1 bird flu virus, according to researchers from UC Davis and UC Santa Cruz. The virus was detected in seven weaned pups at Año Nuevo State Park, with abnormal respiratory and neurological signs observed by a team led by Roxanne Beltran of UC Santa Cruz. Samples collected from sick and dead seals were tested at the California Animal Health and Food Safety Laboratory System, confirming the presence of H5N1. This marks an alarming development in the ongoing global spread of the virus, which has already caused catastrophic die-offs in South American elephant seal populations. In 2022-2023, tens of thousands of seals perished across regions like Argentina and South Georgia Island, with some colonies seeing mortality rates as high as 97%. Researchers had previously noted that northern Pacific populations, including those in California, appeared unaffected, possibly due to prior exposure to milder strains of the virus. However, this new outbreak challenges that assumption. The H5N1 virus has become a significant threat not only to wildlife but also to domestic animals and humans. In the U.S., it has infected millions of cows and poultry, leading to thousands of deaths among animals and at least two human fatalities since 2024. The virus’s ability to jump between species raises concerns about its potential to cause widespread outbreaks in both animal and human populations. The discovery in California highlights the importance of proactive surveillance efforts by researchers. Teams from UC Santa Cruz and UC Davis had been closely monitoring elephant seals at Año Nuevo State Park, where they observed signs of illness in early February. Their rapid response allowed for early detection and testing, which is critical in managing potential outbreaks. The park

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Originally published on Los Angeles Times on 2/25/2026