About 40 dead and 25 injured baby seagulls were found and rescued from South Jefferson Street on Sunday in what seems to be the result of attacks between seagulls.
The Chicago Birds Collision Monitors, which works under the Chicago Audubon Society, received a phone call through its hotline about 2 p.m. When volunteer Chava Sonnier arrived at the scene on her way home, expecting to pick up just one or a few birds, she was “totally shocked.”
“I’ve personally never seen anything of this large a scale before,” she said. “It was truly bird chaos.”
Sonnier rescued about 20 injured seagulls from a sea of eggs, birds and feathers. It was “heartbreaking,” she said, to see surviving birds curled up near their dead siblings or trying to remain with family members.
Another 40 or so seagulls died on impact after falling off the building, while others were run over by cars or died of dehydration and exhaustion. Though she was unable to collect the dead birds, they were later retrieved by other members of the organization.
Though the birds were initially suspected to have been thrown off the rooftop, U.S. Fish and Wildlife concluded upon examining the scene that it is likely adult birds are attacking other birds’ babies and nests.
While the behavior is not uncommon among birds, Chicago field supervisor Louise Clemency said it was unusual “in such large numbers and all at once.”
“It’s something we haven’t seen frequently,” said Annette Prince, director of the Chicago Birds Collision Monitors. “We don’t know if this is a situation about the way the building is constructed, what the weather is like, if there’s too many of them. … We seldom see that many birds all coming down at one time.”
Prince said though it seems to be the result of competition between adult birds, she added that she hopes to keep watch over the area to monitor what may be prompting the attacks.
The surviving birds are being cared for at the Willowbrook Wildlife Center, while dead birds recovered by the organization are taken to the Field Museum.