The deaths in the span of a month of a family of great horned owls that stole the hearts of the Lincoln Park community is likely related to rodenticide poisoning, experts say.
“People watched that little bird grow up and it was a very sad thing that the entire family has now apparently perished,” Annette Prince, the director at the Chicago Bird Collision Monitors, told the Chicago Sun-Times.
“It’s a really tragic end to a family that was really loved in the Lincoln Park area,” Prince said.
The female owl, the last remaining member of the family, was found dead on a sidewalk around 5:30 a.m. Thursday, Prince said.
She was found with blood seeping from her mouth, a sign of internal hemorrhaging from ingesting an anticoagulant, often used in rodenticides, Prince said.
The rest of the family — a male and one baby — were found dead weeks apart in April near North Pond, where they nested. Both deaths are suspected to also involve rodent poisoning.
The male owl had also suffered multiple broken ribs as well as trauma to the side of his body and internal hemorrhaging, according to Sarah Reich, head veterinarian at the Willowbrook Wildlife Center. He was the only one in the family found with broken ribs and trauma to the side of his body. Prince said it wasn’t immediately clear what caused the trauma but told the Sun-Times it was possible he flew into or collided with an object.
Full necropsy results were not immediately available. Reich said it would take about a month for the full reports.
Passersby noticed the adult owls using a tree to nest near Cannon Drive by the North Pond as early as December.
The father of the family hunted and brought back food for the family, while the mother stayed with the baby. None of the birds had nicknames.
“People were pleased and excited to have this family living right in their very neighborhood,” Prince said. “He was quite a celebrity,” she said of the baby owl.
Russ Smith first saw the birds in December, before seeing the baby at the end of February.
The adult owls often sat in trees together, nuzzling and calling to each other, according to Smith, of Lincoln Park. They’d stretch their wings and fly somewhere nearby, often around sunset.
Their offspring, a “small, fuzzy baby,” would walk on the ledge of the tree cavity where the family stayed, Smith said.
“They were really well acclimated to city life,” Smith said. “They were in a busy spot but seemed really well adapted.” Over time, more community members came to visit the birds.
The Chicago Park District put a fence to encourage onlookers to keep a distance, and city officials, police officers and even a CTA bus driver came to get a view of the family during his break along Cannon Drive.
“It was amazing how they acted as a catalyst for bringing people together,” said Smith, who has lived in Lincoln Park for five years.
“A lot of people are angry that such beautiful, affectionate and devoted to each other [great horned owls] all died within the span of about a month.”
An adult great horned owl is typically 18 to 25 inches long with large, hooked talons for catching prey, according to the Illinois Department of Natural Resources. The owls typically live in woodlands and areas of trees or bushes growing closely together.
Prince voiced concerns over the amount of rodent poison traps used throughout Chicago because the rats poisoned by the traps are used by birds for food, which causes the poison to spread.
The impact anticoagulant rodenticide has on an animal depends on the amounts they ingest, Reich said. Cases are treatable through blood transfusions and vitamin K treatment if an affected animal is taken to a licensed care center as soon as possible.
The rodenticide is part of a trap that rodents eat and then when a predator eats a rodent, they secondarily ingest the poison.
“It’s a very serious consideration that cities have to find ways to use nontoxic ways to control things like rats and mice,” Prince said. “Using rodenticides is a very dangerous way to control them because it goes into the food chain.”
The deaths of the owls offer a “stark reality of how important it is to reduce the use of higher-level rodenticides by cities, municipalities and homeowners,” according to Prince.
Seth Magle, director of the Urban Wildlife Institute at Lincoln Park Zoo, said rodent poisoning can also affect the fertility of the owls and their ability to move and fly.
“Because these rodenticides are not really regulated, they can be put by anyone anywhere, and they’re typically used pretty nondiscriminately,” Magle told the Sun-Times. “I think it’s important to step back and realize that we’re not going to solve our rat problem by poisoning all of our rats. … We’re gonna solve it by controlling our trash.”
Some alternatives to using rodenticides include patching holes where rodents can dig through, eliminating food exposure and closing trash lids. If snap traps are needed, Reich recommends only using them indoors so that other species aren’t impacted.
Lincoln Park residents and bird lovers gathered every day to watch the family, some telling Prince that “North Pond would feel every empty” without them.
“I think people related to them,” Prince said. “It was an amazing, close-up experience to be able to watch these birds raise their family right on public display.”
