Taste Preferences of Male Red-Winged Blackbirds among Dried Samples of Ten Corn Hybrids

Abstract

Damage by red-winged blackbirds (Agelaius phoeniceus) to maturing corn results in the loss of about 1% of the United States crop (Stone et al. 1972; Dolbeer 1980, 1981). In some localities, especially near marshes, economic losses can be severe for individual farmers (Wakely and Mitchell 1981). For example, in Ohio, 1.3% of the cornfields receive losses of greater than 5% (Dolbeer 1981). A number of management schemes are used to reduce bird damage. Such schemes sometimes include the use of chemical toxicants (e.g., 4-aminopyridine [Woronecki et al. 1979]), propane exploders, shell crackers and electronic systems to frighten birds from fields, or chemical sprays to reduce roosting populations in corn growing areas (Weatherhead et al. 1980). Unfortunately, because of the difficulties in accurately predicting bird damage and properly timing control, and because of the limited effectiveness and often high cost of such methods, a net benefit is not often achieved (Dolbeer 1981). The use of hybrid corn resistant to bird attack has received little attention; however, findings from the few studies done to date suggest varietal resistance as a promising approach for reducing bird damage. Thompson (1963) evaluated four inbred lines of corn and their single crosses and concluded that bird damage was related to husk extension in the different phenotypes. More recently, Caccamise (1975) and Linehan (1977) documented that bird damage varies widely among hybrids grown in experimental station plantings, and Dolbeer et al. (1982) reported that husk extension beyond the cob tip and husk thickness are significantly and negatively correlated with bird damage. Our preliminary work has suggested that taste properties might also contribute to hybrid resistance. The objectives of the experiment reported in this paper were to investigate taste preferences that male redwinged blackbirds might exhibit among hybrids as well as correlates between preferences and chemical differences among the hybrids.