BIG BEAR LAKE, Calif., Oct. 16 (Nationwide Times) — Bird flu was the “primary underlying cause” of the decline that killed Jackie, the bald eagle from California’s Big Bear Valley, according to Steve Kubiski, director of disease investigations at the San Diego Zoo Wildlife Alliance. Tests found an uncommon form of the illness that damaged her stomach and led to severe complications.
The California Department of Fish and Wildlife released the findings on Oct. 14, 2026, with the alliance and Ojai Raptor Center. Jackie died Aug. 10 while receiving care at the center in Ojai, California, the Los Angeles Times reported.
The findings explain the death of an eagle whose life at a nest near Big Bear Lake, in the San Bernardino Mountains, drew a worldwide following. They also show one way bird flu can harm birds of prey.
What did the examination find?
Veterinary pathologists at the San Diego Zoo Wildlife Alliance performed Jackie’s necropsy — an examination of an animal after death — to investigate what had happened to her.
“In an uncommon presentation of the virus, the infection caused a severe ulcer in her stomach that led to persistent internal bleeding, anemia, and the development of bacterial sepsis,” Kubiski said.
An ulcer is an open sore. Anemia means the blood has too few healthy red blood cells to carry oxygen adequately. Sepsis is a dangerous response to infection.
The damaged stomach tissue allowed bacteria to enter Jackie’s body, according to the wildlife department. Pathologists also found severe inflammation and blood clots in her heart and several major blood vessels.
Follow-up testing detected genetic material from highly pathogenic avian influenza, or HPAI, in several tissues. Those included the ulcerated tissue in her ventriculus, a muscular part of a bird’s stomach.
How was bird flu confirmed?
The investigation involved several laboratories with different roles. The California Animal Health and Food Safety Laboratory at UC Davis performed toxicology tests, which look for poisons, and additional PCR testing for HPAI, according to the wildlife department. PCR tests detect genetic material from a virus.
The U.S. Department of Agriculture’s National Veterinary Services Laboratory system made the final HPAI confirmation. Jackie was identified in her medical records as Patient 26-519.
Was rat poison involved?
Testing detected brodifacoum, a rodent poison, in Jackie’s liver. It is an anticoagulant, meaning it interferes with blood clotting.
“The necropsy did not find uncontrolled bleeding typically associated with anticoagulant rodenticide; therefore, brodifacoum was not identified as the primary cause of illness or death,” the wildlife department said.
Tests also ruled out West Nile virus and harmful levels of heavy metals as contributing factors, the department said.
What treatment did Jackie receive?
Jackie received more than three weeks of intensive care, SFGate reported. AccuWeather reported that she was under intensive monitoring during treatment.
Her treatment included a blood transfusion, oxygen therapy, intensive fluid therapy and anti-parasitic medications, according to the wildlife department’s patient FAQ.
“Together, the findings showed that Jackie was suffering from multiple severe and interconnected disease processes that had been developing over time and ultimately led to her decline and death,” the department said.
Why was Jackie so widely followed?
Viewers watched Jackie and her mate, Shadow, tend their nest through an online video feed for more than a decade, the Associated Press reported.
Millions of people worldwide followed the livestream run by Friends of Big Bear Valley, according to AccuWeather. Shadow remains in Big Bear, the wildlife department said.
How can eagles encounter bird flu?
HPAI primarily affects birds and has circulated among wild birds throughout the United States, according to the wildlife department. Waterfowl and shorebirds are natural hosts of avian influenza viruses.
Eagles and other raptors — birds that hunt other animals — can be exposed through contact with infected birds or by eating infected prey, the department said.
To prevent transmission of bird flu, Jackie’s remains were cremated by the U.S. Fish and Wildlife Service’s National Eagle Repository, according to the wildlife department.
