Scientists stunned by Jackie the bald eagle's cause of death

Jackie, a famous bald eagle who lived at Big Bear Lake in Southern California, died in August after weeks of mysterious illness. She was about 14 years old. Scientists later found out that bird flu — a serious virus also called avian influenza — was the cause of her death. The news shocked many wildlife experts who had been watching Jackie's case closely.

Officials announced on October 14 that a necropsy, which is like an autopsy performed on an animal, showed that a strain of bird flu called HPAI was the main reason Jackie got so sick. Steve Kubiski, a disease expert at the San Diego Zoo Wildlife Alliance, explained the findings. He said the virus caused a bad ulcer in Jackie's stomach, which led to internal bleeding, anemia, and a dangerous blood infection called sepsis. None of those symptoms are what doctors usually see with bird flu.

Dr. William Bowerman, a professor who has studied bald eagles since the 1980s, said Jackie's illness didn't look like a typical bird flu case at all. Usually, an eagle with bird flu might walk in circles, hold its head in a strange way, or be unable to fly. Jackie showed none of those signs, which is why her medical team was confused for so long. 'You would not have suspected bird flu,' Bowerman said.

Jackie was well known because a live camera streamed video of her nest for about ten years. Millions of people watched her lay eggs, raise her eaglets, and spend time with her mate, a male eagle named Shadow. Her death saddened many fans around the world, and because she was so closely watched, scientists paid extra attention to her illness.

The strain of bird flu that killed Jackie is called H5N1. It first started killing large numbers of American bald eagles in 2022, spreading through migratory birds — birds that travel long distances between seasons. The virus can still infect wild birds like eagles today, but Bowerman said there is no major outbreak happening as of late 2026. That is good news, though scientists still don't fully know how much damage the 2022 outbreak did to the bald eagle population.

How Jackie caught bird flu is still a mystery. Bowerman said there was no known bird flu outbreak in her area of Southern California this year. She may have caught the virus at any point — even years ago — and it could have been hiding in her body before it made her sick. The necropsy could not tell scientists exactly when or how she was exposed to the virus.

There are three main ways bald eagles are thought to catch bird flu. They can drink water contaminated by droppings from infected birds, breathe it in near other sick eagles, or eat infected birds such as ducks or geese. Scientists think Jackie may have eaten an infected duck or goose at some point before she got sick. Eating infected prey is believed to be the most common way eagles catch the virus.

Jackie was first taken to the Ojai Raptor Center in July after people saw her in a fight with other eagles. She was in critical condition, and her medical team didn't know why she was ill. She appeared underweight, anemic, and had inflammation in her kidneys. Her doctors looked into many possible causes, including lead poisoning, cancer, and other toxins, and she even received a blood transfusion.

In a strange way, Jackie's unusual case has given scientists a lot of useful information. Normally, when a bird tests positive for H5N1, it is cremated right away to stop the virus from spreading, so doctors don't have time to run many other tests. But because Jackie's doctors didn't suspect bird flu at first, they ran many more tests and tried many more treatments than usual. All of that extra data can now help scientists better understand how bird flu works in eagles — and maybe save other birds in the future.