Excerpt from the report Introduction: Red-winged blackbirds (Agelaius phoeniceus), common grackles (Quiscalus quiscula), and yellow-headed blackbirds (Xanthocephalus xanthocephalus) cause severe damage to ripening crops in North Dakota, South Dakota, and Minnesota. Scientific surveys show that blackbirds damage $4 million to $11 million worth of sunflower each year in these three States. On occasion, blackbirds have destroyed entire fields of sunflower in a few days. Preventing this magnitude of crop damage requires knowledge about the blackbird’s habits and various methods available to prevent damage.