U.S. Department of Agriculture: Animal and Plant Health Inspection Service


Date of this Version

February 2004


Published in National Sunflower Association Research Forum Papers 2004.


The Red-winged blackbird (RWBL) is one of the most abundant birds in all of North America (Dolbeer 1980, Beletsky 1996). Red-winged blackbird damage to crops continues to be a dilemma in localized areas of the United States (Dolbeer 1980). In addition to economic losses, bird damage may intensify conflicts between agricultural interests and the enforcement of laws defending wildlife and their habitats (Stone et al. 1984). When chemicals are shown to be environmentally harmful or when public unease grows over the mass killing of wildlife, new methods of repelling blackbirds need to be evaluated. A more humane and less hazardous technique is the use of aerial lines to repel birds. Although the use of lines is not a new technique (McAtee and Piper 1936), applications have been preformed largely on aquatic sites. Overall aerial lines have shown promise in reducing bird damage in both agriculture and aquaculture facilities. The purpose of the study is to determine if the presence of aerial lines in nesting territories affects reproductive effort of red-winged blackbirds, and determine the spacing, type, and size of aerial lines that serve as an effective deterrent for highly motivated (territorial) red-winged blackbirds.