Maps - Colonial Nesting Waterbird Sites in the U. S. Great Lakes and Nearby Water
These maps show the locations of known colonial waterbird nest sites. There may be additional nesting sites along the shores and islands of the Great Lakes that have not been mapped.
Colonial nesting waterbirds include gulls, terns, herons, night-herons, egrets, and comorants. Gulls and terns nest on beaches. Herons, night-herons, egrets, and cormorants nest on nearshore trees and shrubs. For more about these birds see the Colonial Nesting Waterbirds Fact Sheet (2-page PDF).
The maps do not show locations that are important to migrating birds including island stopovers.
The state maps show only the portion of a Great Lake that is within the respective waters of that state. Thus, if a proposed project is located near a state boundary, look at maps of both states.
Colonial waterbirds use the waters around their colonies to forage for fish. A key predictor of foraging zones around nest colonies is water depth because it's easier for birds to forage in shallow water than in deep water. A general rule of thumb for estimating foraging zones in the Great Lakes is: if a colonial waterbird nesting site is surrounded by or adjacent to shallow water (<60 feet deep), birds will likely forage within 6 miles of the site. If a nesting site is surrounded by or adjacent to deeper water (>60 feet deep), birds will forage up to 15 miles from the site.
rules of thumb, an appropriate foraging zone should be delineated
around each waterbird colony. If wind power development is being
considered within these zones or near waterbird breeding colonies,
pre- and post-construction monitoring should be done to determine
the likelihood of bird collisions with the proposed wind turbines.
If adverse impacts are likely, the project should be sited elsewhere.
These maps were developed by the U.S. Fish and Wildlife Service's Region 3 Conservation Planning Section. The data utilized were provided by Dr. Francesca J. Cuthbert and Ms. Linda Wires at the University of Minnesota and has been collected over a period of three decades.