The Ring-necked Pheasant was introduced into North America (California) from Asia in 1857 and quickly became a popular game bird. The Ring-necked Pheasant is resident on most mid-latitude agricultural lands from British Columbia and California to New Jersey and Nova Scotia. Also introduced into Hawaii and every continent except Antarctica.
Pheasants practice "harem-defense polygyny" where one male keeps other males away from a small group of females during the breeding season. Across the native range, about 34 races of the species are recognized. The Green Pheasant race is sometimes considered a different species. Multiple introductions of different races have been made in North America.