Newsroom Midwest Region

Kirtland’s warblers find Wisconsin a good place to nest

January 16, 2017

Close up of a Kirtland’s warbler in Wisconsin. Photo courtesy of Joel Trick.
Close up of a Kirtland’s warbler in Wisconsin. Photo courtesy of Joel Trick.

The 2017 Kirtland’s warbler nesting season marked the 10th year anniversary of the return of endangered Kirtland’s to Wisconsin. From only 11 Kirtland’s and three nests found in Adams County in 2007 to 53 individuals and 20 total nests among Adams, Marinette and Bayfield counties in 2017, the population has grown and geographically expanded in our decade of conservation work. Kirtland’s warblers are responding to the efforts from dedicated partners, prompting the continued increase in the numbers of individuals and nests in Wisconsin.

In May 2017, the first Kirtland’s warbler of the season was detected at the Adams County site by monitors. Over the course of the week, more were found, and most of the color-banded males occupied territories that they held in previous years. This year, many returning males were unbanded. This may indicate a change in population structure with older males dying and younger males occupying the majority of the male age-structure in the population. It may also indicate an increase in fledgling success since 2015, with more birds returning to the site to breed.

Observers found that male AOJR (color-bands Aluminum, Orange, Black, Red), the oldest known male in Wisconsin at eight years of age, returned to nest this year. AOJR has made eight trips from Wisconsin to the Bahamas and back, totaling approximately 12,000 miles. The oldest Kirtland’s on record is a male that was color-banded in Michigan, thought to be 11 years old.

This season, three enthusiastic and hard-working site monitors joined the Wisconsin Kirtland’s warbler team: Anna Jocham for Adams County, Lake White for Marinette County, and Mike Peczynski for Vilas and Bayfield counties.

Other season highlights included three field trips for the public, habitat management projects in Marinette County, scientific research at the Adams County site, the continuation of projects such as adult and nestling banding, the continuation of the statewide census, new and returning partnerships, and steadfast public interest and support in seeing the success of the Kirtland’s warbler. In addition, the 2017 season was the third year in which observers detected nesting in Adams County outside of the core breeding area. In 2017, the core breeding site in Adams County, part of a Wisconsin Department of Natural Resource easement for Kirtland’s warblers, was sold by Timberland Investment Resources and purchased by Sand Valley Restoration LLC. Partners look forward to working with Timberland and are appreciative of their interest in Kirtland’s warbler conservation.

Kirtland’s warbler Wisconsin conservation partners include the University of Wisconsin, the Service’s Ecological Services and Partners for Fish and Wildlife programs, Wisconsin Natural Resources Foundation, U.S. Department of Agriculture - Wildlife Services and multiple county forests. Learn more in the full report including details of the 2017 Kirtland’s warbler Wisconsin breeding season.