Sleeping Bear Dunes National Lakeshore Grassland Bird Inventory Geodatabase (2002 Data)

Corace III, R.; Goebel, Charles; Wyse, Thomas

An ERSI Geodatabase created to document a grassland birds inventory conducted in Sleeping Bear Dunes National Lakeshore during 2002. Additional breeding bird survey data was used. Abstract from resulting report: Throughout much of North America populations of openland (grassland-shrubland-early successional forests) birds have been declining dramatically, primarily in response to the loss of available habitat. In the Upper Midwest, some lands managed by the National Park Service, such as those at Sleeping Bear Dunes National Lakeshore, contain historic cultural openlands that may provide important habitat for some openland bird species. With this in mind, we characterized the plant and bird communities of historic openlands (fields) of Sleeping Bear Dunes National Lakeshore at multiple scales. At the Lakeshore scale, we characterized the openland bird community and produced an ordinal scaling of abundance based on the frequency of encountering each species. We found the bird community associated with these openlands to be comprised of 13 openland species of conservation priority as deemed by the United States Fish and Wildlife Service Region Three (Midwest): black-billed cuckoo, bobolink, Connecticut warbler, eastern meadowlark, field sparrow, grasshopper sparrow, Henslow’s sparrow, Le Conte’s sparrow, northern harrier, sedge wren, upland sandpiper, western meadowlark, whip-poor-will. We then investigated long-term population trend data for all bird species encountered to assess on a relative basis the conservation value of openland habitats. At the field scale, we delineated the boundaries and quantified the spatial characteristics (e.g., area, perimeter, edge type) of 12 fields currently managed under the Lakeshore’s Meadow Management Plan. Additionally, we characterized the overstory and ground-flora vegetation of the major habitat types (e.g., building edge, field edge, field interior, forest edge, forest interior) associated with each field. The results of these analyses suggest that the composition and structure of the overstory and ground-flora plant communities of the building edge, field edge, and field interior habitat types are similar, while the forest edge and forest interior habitats are reflective of either a sugar maple-red oak forest type or a sugar maple-beech-eastern hemlock forest type. Finally, we estimated the density of birds inhabiting these fields and related these values to habitat structure and composition. Our analyses suggest that the density of many openland species is regulated by the interaction of field size, shape, and edge type. Based on the findings of this study and ongoing openland assessments at larger spatial scales, we suggest that maintaining the larger or more contiguous patches of these historic openlands will benefit local, state, and regional (Upper Midwest) populations of openland birds. (From Corace, R. G., III, P. C. Goebel, and T. C. Wyse. 2009. A multi-scale assessment and evaluation of historic openlands at Sleeping Bear Dunes National Lakeshore. Natural Resource Technical Report NPS/GLKN/NRTR—2009/150. National Park Service, Fort Collins, Colorado.)