Bird Flu confirmed as primary cause of Big Bear bald eagle Jackie's death, raising concerns and what it means for other raptors

Big Bear’s famous bald eagle, Jackie, died months ago, and people waited to learn what happened to her. The eagle died on August 10 after becoming ill and receiving treatment at a wildlife rehabilitation center. The final necropsy results have provided an answer. The California Department of Fish and Wildlife has found the primary underlying cause of her sad demise.

The findings also explain how the infection caused internal bleeding and other severe complications. They give information about the risks the virus has for eagles and other birds of prey. The findings are taken from CDFW, Popular Science and VVNG.

Jackie died on August 10 after receiving treatment at Ojai Raptor Center. Her case has given wildlife specialists a clearer picture of how the disease can affect an eagle.

Necropsy revealed about Jackie’s death

Veterinary pathologists at the San Diego Zoo Wildlife Alliance performed Jackie’s necropsy supported by laboratory and toxicology testing coordinated with the California Department of Fish and Wildlife.

The director of disease investigations at the San Diego Zoo Wildlife Alliance Steve Kubiski explained the findings.

"Jackie's necropsy confirmed Highly Pathogenic Avian Influenza (HPAI) as the primary underlying cause of her decline," he said. HPAI is commonly known as bird flu. "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."

The examination found severe inflammation and ulceration in Jackie’s ventriculus. It is the muscular part of a bird’s stomach. The damaged tissue caused ongoing blood loss and severe anemia. It also allowed bacteria to enter her body, resulting in a serious secondary infection.

Veterinarians also found inflammation and blood clots in her heart and major blood vessels. Tests detected bird flu virus genetic material in several tissues throughout her body, including the damaged stomach tissue.

Jackie tested negative for West Nile virus. Heavy metal levels, including lead, were within acceptable limits. Although testing detected brodifacoum, an anticoagulant rodenticide, in her liver, it was not identified as the primary cause of her illness or death.

Why is bird flu a concern for other eagles and raptors

Avian influenza is caused by type A influenza viruses that naturally move around in waterfowl and other waterbirds. These viruses come in forms, like H5N1, named after two proteins on their surface. Hemagglutinin and neuraminidase.

The pathogenic H5N1 strain found in North America has spread quickly since it was first spotted in domestic poultry and wild birds along Canada’s Atlantic coast in December 2021. It reached birds and farm birds in the eastern United States early in 2022 and has now spread to almost every state.

According to CDFW this current strain of H5N1 has made kinds of wild birds sick and caused deaths, in a wider range of species than earlier outbreaks did.

Eagles and other birds of prey can be exposed when they eat infected waterfowl or come into contact with areas heavily contaminated by virus shed by infected birds. This makes the disease a concern for predators and scavengers, including hawks, falcons and owls.

The effects are not the same in every bird. Some infected wild birds may show no obvious signs of illness. Others can become severely sick. The outcome depends partly on the bird species and the virus subtype and strain.

CDFW’s Wildlife Health Lab works with regional staff and partner organizations to monitor wild birds, investigate deaths and test for avian influenza. The agency gives particular attention to mortality events involving five or more wild birds. It also supports national surveillance testing of waterfowl led by the U.S. Department of Agriculture.

What does Jackie’s death mean for Shadow and other wildlife

Jackie’s death left Shadow without his longtime mate, but there is no evidence that he or the pair’s eaglets were sick, according to CDFW.

Chris Eksteen, executive director of Ojai Raptor Center, said the necropsy helped explain the medical problems seen during Jackie’s treatment.

“The necropsy results have helped connect many of the findings we were seeing throughout the eagle’s hospitalization,” he said. “We are grateful to the many veterinary specialists, laboratories, wildlife agencies and partner organizations who worked alongside our team to understand her illness and provide her with the best possible care. Caring for her was an extraordinary privilege for our entire team.”

Jackie’s remains were cremated by the U.S. Fish and Wildlife Service’s National Eagle Repository under procedures intended to prevent the virus from spreading to wildlife or humans.

Her case does not mean every infected eagle will develop the same stomach damage. But the findings provide veterinarians with a better understanding of the serious complications HPAI can cause and may help inform the treatment of other affected birds.



For the people who watched Jackie and Shadow through the Big Bear Valley livestream, the results bring some clarity after months of uncertainty. For wildlife specialists, they offer another important piece of evidence about a virus that continues to affect birds across North America.