Kirtland’s Warbler is a rare species of bird that had been known to breed only in 13 contiguous counties in northern lower Michigan. It’s nesting habitat needs are very specific: jack pine stands of a certain age. Fire once ensured that such habitat existed. We no longer tolerate natural fire. The 2008 census of this species at its Michigan sites found fewer than 2,000 singing males (singing males because you have to locate them to count them). Now, however, the bird has expanded its range into at least two parts of Wisconsin, the major site less than a two-hour drive from Minnesota — Adams County, which is about 100 miles east of LaCrosse. This nesting season there has been called extremely successful. To put that in perspective, we’re talking about five nests in Adams County that fledged a total of 19 birds. Male Kirtland’s Warblers have been found at two sites in Marinette County, on the Michigan border. One nest containing three eggs was found there. One singing male has been reported from Douglas County (far northwestern Wisconsin) this summer, but the bird has not been relocated. In 2008, Kirtland’s also were reported from Vilas and Jackson counties, but confirmation was not made. Habitat is one problem for the Kirtland’s Warbler, cowbirds another. In Michigan and at the Adams County locations cowbirds are being trapped to reduce the degree of parasitism that can make warbler nesting seasons fruitless. The photo is of a recently fledged Kirtland’s. It was taken by Joel Trick of the U.S. Fish and Wildlife Service, and is used with permission. 

This entry was posted on Saturday, July 18th, 2009 at 9:37 am and is filed under Bird biology, Bird conservation, Bird records. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.