Proceedings of the Vertebrate Pest Conference

Bait preference studies with red-winged blackbirds (Agelaius phoeniceus) in North Dakota sunflower fields indicated that sunflower seeds and a combination of sunflower seeds and chopped corn (MIX) were more successful in producing affected blackbirds, primarily red-winged blackbirds, than pearl barley or chopped corn used separately. A subsequent study compared the effectiveness of commercial Avitrol FC corn Chops-99S to 4-aminopyridine-trealed MIX-99S baits for reducing blackbird damage to ripening sunflower. Both baits significantly reduced damage in fields nearest a blackbird roost (within two miles), but were largely ineffective in fields farther than two miles from a roost. The ramifications of these results are discussed.