Eliason, B. 1989. Kirtland's warbler: results of 1989 survey work in Minnesota. Final report submitted to the Minnesota Department of Natural Resources. 10+ pp.
The Kirtland's Warbler is a federally endangered species that is known to breed in only a few counties in northern lower Michigan. Preferred breeding habitat is dense jack pine stands of wildfire origin in which trees are 1.7 to 5.0 m tall. Dispersal of young birds is adaptive in species occupying such ephemeral habitat. The fate of dispersing birds is of interest; their failure to acquire mates might account for the failure of the population on the traditional nesting area in Michigan to grow despite high fledging success in recent years.
Occasional singing males observed outside the traditional breeding area may represent dispersing individuals. The Kirtland's Warbler recovery plan recommends a search of adjacent states and Canada to locate, quantify, and band these "wanderers" in an attempt to determine their importance to the population biology of the species. Recent survey work in Wisconsin in 1988 yielded sightings of eight singing males in 3 counties, including Washburn and Douglas counties in the western part of the state. The proximity of these sightings to Minnesota prompted interest in conducting a similar survey in the east-central region. A detailed account of methods used to identify suitable habitat in Minnesota may be found elsewhere. This report summarizes the 1989 field survey work in Minnesota, during which 75 sites comprising approximately 7000 acres in 5 counties were surveyed, and no Kirtland's warblers were located.