The Illinois Department of Natural Resources says thousands of birds died after eating poisoned seeds. But investigators aren't ready to say if it was an accident or if someone intentionally killed them, reports Correspondent Jason Whitely of CBS Affiliate KMOV-TV in St. Louis.
Wheat soaked with an agricultural insecticide may have killed as many as 27,000 birds in a southern Illinois field.
The birds were found Saturday in a field near Freeburg, Illinois and experts fear the number of dead wildlife could grow.
About 75 percent of the dead birds were red-winged blackbirds. The rest were brown-headed cowbirds, grackles, starlings and horned larks, said Georgia Parham of the U.S. Fish and Wildlife Service.
Only two of the more than 27,000 birds survived the deadly dinner. One is a red winged black bird. It apparently didn't eat a lethal dose. The other is a young red tail hawk. It threw up the carcass of a poisoned bird. Officials say both should recover.
The insecticide Furidan - a chemical usually sprayed directly on a crop - was spread on the St. Clair County winter wheat field, said Capt. Mark Ottis, a state conservation officer.
State Department of Natural Resources spokesman Joe Khayyat said the insecticide was used "apparently for the sole purpose of eliminating a population of blackbirds that were perceived to be a nuisance."
No charges have been filed, pending the outcome of lab tests on the carcasses. Authorities said the land owner is cooperating with investigators.
If the poisoning was intentional, the farmer could face federal charges since migrating birds are protected by federal law, Parham said. Officials had first suspected that a downdraft killed the birds by slamming them into the ground.
Workers finished picking up the carcasses Wednesday to prevent other animals from eating them and possibly becoming sick. Officials said there is no danger to humans.
The Fish and Wildlife Service, the U.S. Environmental Protection Agency and the St. Clair County state's attorney's office were investigating.