In the United States, more than 90% of cultivated sunflower is raised in the northern Great Plains. Cattail marshes in this area provide nesting and roosting sites for red-winged blackbirds, yellow-headed blackbirds, and common grackles. North Dakota's breeding blackbird population was estimated at more than 2.3 million pairs in 1990. Sunflower has become an important part of blackbirds' diet from July-October . In 1999 and 2000, research was conducted on the use of avicide-treated (DRC- 1339, 3-chloro-p-toluidine hydrochloride) rice baits for managing blackbird damage in problem areas. DRC- 1339 was chosen for this purpose because of its high toxicity to blackbirds and low toxicity to mammals and some species of nontarget birds, especially sparrows, finches, and most raptors.
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