Ring-necked pheasants aren't native to Illinois or even the United States, but these birds have been common since the 1800s after being introduced as a game bird.
Ring-necked Pheasant Overview, All About Birds, Cornell Lab of Ornithology
Ring-Necked Pheasant Facts
Ringneck Pheasant: America's Gamebird
Forest Preserve District of Will County
Unwelcome by Some, the Ring-necked Pheasant Is an American Success Story
Pheasants losing habitat to farmland
CDFW News New Surcharge on Bird Hunting Validations to Provide Nesting Habitat for Waterfowl, Upland Game Birds in California
Cute Common Pheasant by Birdorable < Meet the Birds
Taking Flight: 2009
Pheasants are harder to hunt without canine assistance, but the flush is just as thrilling