Cattail stands provide roosting and staging areas for large congregations of blackbirds in North Dakota in late summer and early fall. Since 1991, the U.S. Department of Agriculture, Animal and Plant Health Inspection Service, Wildlife Services (WS) program has conducted a cattail management program in North Dakota to alleviate blackbird damage to ripening sunflower. To extend the capabilities of the program, a geographical information system (GIS) will be incorporated to help WS personnel find blackbird roosts more effectively. We will use the GIS to construct field maps showing the association between areas of moderate to high sunflower damage (>5%) and cattail-dominated wetland basins >2 ha. Buffer distances comparable to the distances blackbirds typically travel to forage will be placed around sunflower planting areas susceptible to high damage. This will help WS personnel focus their efforts on locating cattail-dominated wetlands that should be enrolled in the management program and improving current and future blackbird damage management programs.