Land use/land cover patterns of bald eagle (Haliaeetus leucocephalus) nesting habitat in the northern Lower Peninsula of Michigan.

摘要

A GIS was used to determine if a pattern in bald eagle nest areas and reproduction exists in relation to land use/land cover patterns in Michigan. Habitat analyses were conducted at three level: nests sites in the Black River Watershed, breeding areas in the northern lower peninsula and nest sites in the northern lower peninsula (NLP) of Michigan. I examined the change in land cover over time, proportion of land cover types in nest and breeding areas and the relationship between nesting and production associated with surrounding land cover. I used 1993 GAP land cover data to develop a habitat model for nests in the NLP. Over all scales, bald eagles preferred land cover that included lowland forested areas, and avoided land cover that included urban and non-forested areas. Logistic regression models demonstrated distance to water as the most important variable in nest location. Results suggest that proportions of land cover types among nests is highly variable, but general nest site preferences do not seem to be changing. As the eagle population continues to expand, the availability of optimal breeding areas will decrease, and breeding pairs settling in sub-optimal areas may experience lower reproductive rates. Results of the analyses and methods that were developed should provide information useful in identifying future potential habitat for nesting bald eagles in Michigan.