The third and final member of a family of great horned owls living in Lincoln Park’s North Pond was found dead Thursday morning. Experts said the bird is suspected to have died from rodent poisoning.
The adult female owl was found covered in blood, Annette Prince of Chicago Bird Collision Monitors said, a condition that indicates rat poisoning. It will be transported to the Willowbrook Wildlife Center to determine a cause of death.
“This was a tragic outcome,” said Prince. “The family was thriving there in North Pond. We need to petition our cities and municipalities and encourage our neighbors not to use these high amounts of poison.”
The owl’s adult male partner and their baby owl were found dead in recent weeks in the pond area. Experts suspect that rodent poisoning played a role in both owls’ deaths.
Sarah Reich, head veterinarian at the Willowbrook Wildlife Center, said the baby owl experienced massive amounts of internal bleeding and almost certainly died from rodent poisoning. His father experienced two broken ribs but also had internal bleeding and is being tested for rodent poisoning, she said.
Reich said birds with broken ribs are often able to survive, indicating some kind of underlying cause.
Even if rodent poisoning is not the final cause of death for a bird, it can often contribute, according to Holly Fales Garvey, a volunteer environmental educator at the Lake County Forest Preserve District.
She said she sees a lot of birds die from hypothermia after becoming lethargic and slow from rat poisoning, while other birds become weak enough they fall out of trees or are hit by cars.
“The animals bleed out from the inside,” Fales Garvey said. “They don’t know what’s wrong with them, they try to get water, as if that’s going to help them. And then what we see with our big birds is that they will actually succumb to hypothermia after they end up in the water.”
Red crossbills, bald eagles and other unexpected birds have been spotted in Chicago this winter
Almost 4 million great horned owls can be found in a variety of habitats across North America, including in Illinois. The second-heaviest owl species in America after snowy owls, great horned owls are known for their hunting skills, big yellow eyes, deep hoots and the feather tufts on their heads. They nest as early as January, since their owlets need more time than other young birds to learn to hunt on their own ahead of the next winter.
Candace Ridlbauer, who runs Northern Illinois Raptor Rehab and Education, said she sees a lot of birds die by rodent poisoning. She said it’s important for Chicago residents who experience a rodent problem to find a solution that does not involve poisons.
“It gets into the food chain,” Ridlbauer said. “It’s not just birds. Fox, coyotes, all kinds of birds of prey eat mice. Your cat might eat mice. Find someplace that removes pests humanely, so that you’re not putting out these types of poisons.”