Saturday, July 11, 2009
Lucky 19: Kirtland's Warbler Update in Wisconsin
(Above, a fledgiing Kirtland's Warbler in Adams County, Wisconsin. Copyright Joel Trick, Wisconsin DNR.)
According to a Wisconsin DNR news release from July 6, 2009, 19 Kirtland's Warbler young have hatched in the state this breeding season.
(As background information for the uninitiated, historically and through 2006, Michigan was considered the endemic breeding range of this species. Only periodic, non-annual sightings were reported in Ontario (including one nesting record in 1945) and Wisconsin, with no documented nests ever found in Wisconsin. This scenario changed in 2007 when Kirtland's was confirmed as a nester for the first time in Wisconsin.)
Here's more information about the ongoing monitoring in 2009 of Kirtland's Warbler within two Wisconsin counties:
Wisconsin Kirtland’s warblers have had an extremely successful nesting season in 2009, and have already surpassed the reproductive output of last year. As of today, at least five Adams County nests have fledged young, including two nests that each produced four young over the weekend. So far a biologist has determined that the nests that have fledged contained a total of 19 young when checked just prior to the young leaving the nest. Another nest that is currently being incubated is expected to hatch within the next week or so. This nest is the renesting effort of a pair that had previously been parasitized by cowbirds. One nest that was expected to fledge soon was empty today, and the behavior of the adults suggests it may have been lost to predation. The biologist has currently been unable to find the nest of one additional pair at the site, but he will continue to search in the days ahead.
Male Kirtland’s warblers are known to be present at two separate sites in Marinette County, and each has previously been observed with a female. On Thursday, a DNR volunteer monitor found a nest containing three eggs at one of these sites. Finding eggs at this late date suggests that this may be a renest after an early failure. If successful, this would be an important nesting record for Marinette County. We will continue to monitor this nest to determine its outcome.