NCRS - The Changing Midwest Assessment

Relative Abundance of Birds

In the 7-states of the North Central Region approximately 25% of the bird species surveyed by the North American Breeding Bird Survey have declined significantly in abundance since 1966. Although previous studies indicate that changes in land use, habitat loss and fragmentation, and urban sprawl may have negative impacts on the relative abundance and distribution of birds, there are no regional scale analyses that link temporal changes in land use and land cover to change in bird populations. As a first step in the process of understanding the forces that are driving declines in breeding bird populations we have developed spatially explicit maps that depict trends in the relative abundance of breeding birds populations. We selected birds that live and or breed in each of the major habitat types present in the Region, including: Urban/Early Successional, Grassland, and Woodland. To view a list of bird species by habitat type, and to access the relative abundance maps, click on the embedded text or select from the images above.