Date of this Version
The spread of cattail across the Northern Great Plains has increased the amount of breeding and roosting habitat available to marsh-nesting blackbirds. In the fall, dense cattail stands attract large numbers of roosting blackbirds, that damage crops like sunflower. In an effort to disperse roosting blackbirds and reduce the resulting crop damage, scientists from the USDA’s National Wildlife Research Center and North Dakota State University have developed wetland habitat management techniques using a glyphosate-based aquatic herbicide. These techniques have been used by USDA Wildlife Services as a nonlethal method for reducing blackbird damage. Previous research on individual wetlands has demonstrated that wetland habitat management can disperse congregations of roosting blackbirds, reduce the number of breeding blackbirds, and increase attractiveness of the wetlands to other wildlife, like waterfowl. The prospect of an expanded cattail control program has raised concerns about the scale of management efforts and the effects of habitat alterations on other wetland species. A precise estimate of the amount of cattail habitat presently available will form a basis to address concerns about the overall scope of the cattail management program.