During late summer in the Delaware Valley and Chesapeake Bay region, hundreds of thousands of Red-winged Blackbirds feed in wild rice beds of fresh tidal-river marshes. The period during which wild rice seed is available coincides with the ripening period of a part of the corn crop, and there is evidence to indicate that the availability of the wild rice reduces bird feeding pressure on corn in the area. The importance of wild rice and other marsh plants to the redwing during the period when wild rice seed is available was studied further by field observations and by analysis of stomach contents of 130 birds collected in wild rice beds of the Patuxent River in southern Maryland. Seeds of marsh plants formed the bulk of the food of redwings collected. Dotted smartweed, wild rice, and Walter?s millet were the most important food plants. Corn was the fourth most important item. It occurred in 35, approximately one-fourth, of the stomachs