Department of Biological Sciences, North Dakota State University


Scott Ralston

M.S. Student (Dr. Will Bleier)

Office: Stevens Hall 115

Phone: (701) 231-8055

B.S. North Dakota State University

Zoology (Fisheries & Wildlife) (2002)

Research Interests:

Avian Ecology, Prairie Wetlands, Pest Management, Ecological Applications of GIS

Basis for my research:

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, which 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 (NWRC) and North Dakota State University (NDSU) have developed wetland habitat management techniques using a glyphosate-based aquatic herbicide. These techniques have been used by the USDA's Wildlife Services as a non-lethal 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. Up to this point, cost and logistical constraints have limited the application of glyphosate herbicide to targeted areas. However, the NWRC and ND/SD Wildlife Services have been testing additional application techniques, which are likely to reduce costs and remove logistical problems. Additionally, the price of glyphosate herbicide has declined as manufacturers have produced generic versions.

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 rigorous 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. This study will also form a guideline for future cattail abundance estimates.


The PPR was stratified based on biotic differences, and a total of 120, 10.36km^2 sample plots were randomly selected within these strata. Aerial infrared photos were taken of each site in August and September of 2002 and imported into a GIS. Wetlands with cattail were identified, and a supervised classification was used to delineate cattail area. Other wetland attributes were also identified including basin size, classification, cattail density and presence of water.


Results concluded that within the 95,172km2 of the PPR in ND, approximately 2.33%±0.27% of this area was covered by cattail, with the highest densities in the Northeast Drift Plains and Southern Drift Plains. The amount of cattail reduced annually by the USDA Cattail Management program represented less than 1% of the total available cattail. The majority of cattail was found in semi-permanent wetlands. Cattail was found more often in areas with higher densities of wetlands and in wetlands with at least some standing water. Average cattail wetland size was 2.64ha with larger wetlands being found in the Missouri Coteau.


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Last Modified: January 24, 2005
Published by Department of Biological Sciences, NDSU