Jackie the bald eagle mysterious cause of death finally revealed after months of questions

Millions of people watched Jackie, the beloved Big Bear bald eagle, raise her chicks, survive brutal winter storms and defend her nest alongside her longtime partner, Shadow. But when the famous California eagle suddenly became seriously ill and died in August, one question remained unanswered: What really happened to her?

Jackie’s final weeks were marked by an unusual series of medical complications that puzzled wildlife specialists. She had been found weak and unable to fly near Big Bear Lake in July, shortly after an encounter with two younger eagles. What initially appeared to be an injury-related emergency quickly became something far more complicated.

Despite weeks of intensive veterinary care, blood transfusions and advanced testing, Jackie died at approximately 14 years old. Early examinations identified severe anemia, blood clots and abnormalities affecting several organs, but none provided a definitive explanation for her decline. Now, more than two months later, scientists have finally identified the underlying cause.

What was Big Bear bald eagle Jackie’s cause of death?

The California Department of Fish and Wildlife announced on October 14 that highly pathogenic avian influenza (HPAI), commonly known as bird flu, was the primary underlying cause of Jackie’s deterioration and death.

The findings came from a comprehensive necropsy conducted by veterinary pathologists at the San Diego Zoo Wildlife Alliance, supported by additional laboratory and toxicology testing.

The infection had triggered serious internal complications, including a severe stomach ulcer. Jackie also suffered from chronic disease affecting her gizzard, an organ birds use to grind food. These conditions contributed to blood loss, anemia and a secondary bacterial infection, helping explain why her health continued to deteriorate despite intensive treatment.

Scientists also discovered something unexpected

The investigation uncovered another concerning finding: traces of brodifacoum, a powerful anticoagulant commonly used in rat poison, were detected in Jackie’s liver.

The discovery raised additional questions about the environmental hazards faced by wild birds of prey. Bald eagles can be exposed to rodenticides indirectly when they consume contaminated animals.

However, investigators emphasized that the poison was not identified as the primary cause of Jackie’s death. The necropsy did not reveal the uncontrolled bleeding typically associated with fatal anticoagulant poisoning.

Tests also ruled out West Nile virus and heavy-metal exposure as contributing factors. The final findings suggest that Jackie’s illness involved several overlapping medical problems, with avian influenza at the center.