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.
The American Ring-Neck Pheasant
Hunting the pheasant America's most popular upland bird
Common pheasant - Wikipedia
Lockport Prairie Nature Preserve
Mr. Ring-necked, Though not native to North America (introd…
Ring-Necked Pheasants - prdseed
Ring-necked pheasants not native to U.S. but have thrived as a game bird
Unwelcome by Some, the Ring-necked Pheasant Is an American Success Story
Lockport Prairie Nature Preserve
The ring-necked pheasant - DesertUSA
The National Wild Pheasant Conservation Plan, Second Addition – Implications for Illinois
Forest Preserve District of Will County
Klemek: Ring-necked pheasant is 'king of the game birds' - Detroit Lakes Tribune
Lockport Prairie Nature Preserve
Hunting the pheasant America's most popular upland bird