Date of this Version
Published in G.M. Linz, M.L. Avery, and R.A. Dolbeer, editors. Ecology and management of blackbirds (Icteridae) in North America. CRC Press, Boca Raton, FL. Pgs. 207-216.
There are nearly 1,000 species of birds in North America, some of which provide obvious economic benefits like egg production, meat production, bird watching, or hunting (American Bird Association 2016). Some bird species, however, can cause a considerable amount of damage to U.S. agriculture, with estimates of annual damage caused by birds in the United States exceeding US$4.7 billion (Pimentel et al. 2005). Blackbirds (lcteridae) are one group of birds in North America that can cause significant economic damage to commercial grain crops, and to a lesser extent vine and tree crops (Wilson et al. 1989; Dolbeer 1990; Linz et al. 2011; Anderson et al. 2013).
Four species of blackbirds-red-winged blackbird (Agelaius phoeniceus), common grackle (Quiscalus quiscula), yellow-headed blackbird (Xanthocephalus xanthocephalus), and brown-headed cowbird (Molothrus ater)-are primarily responsible for damage to sprouting and ripening grain crops (Lowther 1993; Twedt and Crawford 1995; Yasukawa and Searcy 1995; Peer and Bollinger 1997). During late winter, these species commonly can be found feeding on food present in concentrated animal feedlot operations (Dolbeer et al. 1978). For much of the year, however, these birds forage on insects, waste grain, and weed seeds, thus providing valuable ecological services.