Crop depredations by red-winged blackbirds (Agelaius phoeniceus) have been a problem since colonial times (Cardinell and Hayne 1945, Weatherhead and Bider 1979, Dolbeer 1980). Today, tens of millions of dollars worth of corn are consumed yearly by blackbirds (Stone et al. 1972, Dolbeer 1980, Tyler and Kannenberg 1980) and the problem appears to be increasing. Most of the initial efforts to reduce blackbird damage to corn and other crops focused on techniques to reduce redwing populations or on chemical and mechanical repellents and frightening devices (Dyer and Ward 1977). The inconsistent effectiveness of these techniques, however, has indicated the need for an integrated approach to understanding the ecological relationships between red wings and corn (Dolbeer 1980, Dolbeer et al. MS)
