Wildlife Damage Management, Internet Center for


Date of this Version

October 1973


Blackbirds, Red-winged Blackbirds in particular, have caused millions of dollars worth of damage to corn crops in Ohio and Michigan and throughout the country. Concentrated efforts to estimate and document the damage in Ohio and Michigan were initiated in the fall of 1966. Besides yielding an annual estimate of blackbird damage, it was hoped that the survey would eventually be held to establish the effectiveness of control efforts, particularly the use of Avitrol. However, the large variability inherent in the damage sampling procedure has precluded documentation of changes in the amount of damage due to control efforts. In order to detect such changes, either a much larger sample would have to be taken or control efforts throughout Ohio and Michigan would have to be increased significantly. Agencies which cooperated with the Bureau of Sport Fisheries and Wildlife in conducting the survey were the Ohio Department of Agriculture, the Ohio Agricultural Research and Development Center, and the Ohio Cooperative Extension Service.