Using Geographic Information Systems to determine potential Bald Eagle nesting sites in Washington County, MN

Abstract

In North America, there is only one native eagle, the bald eagle (Haliaeetus leucocephalis). The bald eagle population in the lower 48 states of the United States of America has declined dramatically. The population was estimated to be as much 500,000 in the 1700s, and it has fallen to approximately 20,000 in 2000. In 2000, Minnesota had an estimated 680 breeding pairs of bald eagles. Sixteen of the thirty-five active breeding sites in the Twin Cities Metro Area are located in Washington County. Geographic Information Systems (GIS) helped to determine where potential nesting sites are in Washington County. Slope and aspect of the known nesting sites were measured to determine the GIS model. The GIS helped establish other characteristics of the existing nests, such as distance to open water, proximity to roads, railroads and other man-made features. By developing and analyzing the GIS model of bald eagle nests, it was concluded that of the 1,015 square kilometers in Washington County, 88 square kilometers would be suitable for bald eagle nests.