Using birds as indicators of biodiversity status for two North Dakota counties
Results/Conclusions The biodiversity index was based on summing individual bird habitat suitability indicators and rescaling the total between zero and 100. When the biodiversity index was based on even weighting of individual bird indicators, average values for Grand Forks County were 61 for grassland, 32 for cropland, and 17 for developed land. The average values for Stutsman County were 57 for grassland, 31 for cropland, and 11 for developed. When three species with positive associations with croplands and developed areas were not included in the combination, index values on cropland and developed land decreased for both counties. Wetland analysis was undertaken separately at a finer scale, and results were incorporated into the final index by merging grids. Overlays for wetlands based on two obligate wetland bird species alone, produced a mean biodiversity index for wetlands of 58 for Grand Forks County and 68 for Stutsman County. These results indicate that birds can be used to develop a useful biodiversity index, but that index values are highly sensitive to the way individual indicators are combined, the resolution of the analysis and scaling of features, and the quality of the data that relates bird behavior to habitat.