Each autumn, millions of birds migrate from their breeding grounds in the northern hemisphere to wintering areas in the continental United States, Mexico, Central America, and South America (Rich 2004, Bildstein 2006). The North Shore Highlands parallels the Lake Superior shoreline from Duluth through Grand Portage, Minnesota to the US border with Canada. This region’s prominent ridgelines and Lake Superior coastline funnel migrating birds into this migration corridor (Hofslund 1966, Mueller and Berger 1967, Bildstein 2006). As a result, the North Shore Highlands hosts the largest migratory route for birds of prey in Minnesota and is among the highest in the US. In addition, recent data suggest that the numbers of nonraptor bird species moving along the north shore of Lake Superior are orders of magnitude larger than those for raptors.
Migration periods constitute a critical life-stage for these birds as mortality rates may be higher during migration than during breeding or over wintering periods (Sillett and Holmes 2002, Smith and Moore 2003). Large bodies of water and other major topographical features cause a nonrandom distribution of migrating birds on the landscape in both periods of active flight and rest (Goodrich and Smith 2008). Landscape features that define the North Shore Highlands (Lake Superior, ridgelines, river valleys) result in a major congregation of migratory birds (raptors and passerines) that are both actively flying and resting within the region.
With the current emphasis on renewable energy (Great Lakes Commission 2011), the North Shore Highlands region has become a focal point for potential wind power, with many plans already in progress (Mageau et al. 2008). Besides wind turbines there is also increased activity in the development of communication towers in the region. The North Shore Highlands region is recognized as one of the top tourist destinations in Minnesota and the upper Midwestern US. Over the past twenty years, the area has experienced increased developmental pressure from recreation, tourism, and exurban housing (MNDNR 2006).
Conservation strategies aimed at the protection of migratory birds are incomplete without the focus on migratory bird flyway and stopover habitat preservation (Petit 2000, Mehlman et al. 2005). To develop conservation strategies to protect en route migratory birds within this region, there is a need to understand the cues by which migrants choose migratory flight paths and stopover habitats (Ewert et al. 2011, Buler et al. 2007, Bonter et al. 2009). Our overall goal is to provide data and mapping products that will contribute to a comprehensive conservation plan for migratory birds highlighting the potential risks of wind energy development within the North Shore Highlands region. We have worked closely with several community groups in the region (e.g., Grand Portage Indian Reservation, Cook County Local Energy Project, and Lutsen Mountains Resort) who have expressed an interest in wind energy development. Our purpose will be to eliminate or minimize interactions with migratory birds if wind turbines are placed in the North Shore Highlands region.