1999: Small game harvest survey changed from a single (1998) to a double mailing (1999). Harvest estimates from 1999-present are more conservative than pre-1999 estimates.
2000: Survey methods changed account for unrealistic harvest (e.g. reports of 1 bird harvested for 60 days effort), hunters asked to report days they hunted rather than trips.
2022: Poor sample from small game survey makes pheasant, cottontail and squirrel estimates highly suspect.