Kirtland's Warbler Habitat

The Kirtland's Warbler

The Kirtland's warbler was discovered during migration in 1851 by Dr. Jared P. Kirtland on his farm near Cleveland, Ohio. About 50 years later, the bird's nesting ground was discovered near the Au Sable River by two trout fishermen. After their fishing trip, one of the fishermen reported the find to Norman Wood at the museum in Ann Arbor. Wood travelled to locate the bird in its breeding habitat.

After locating a singing male, Wood described the song of the Kirtland’s warbler in these words: "It is a song so clear and at the same time so joyous that words of mine are a poor expression. Its song, the most beautiful of any warbler, is so wild and clear and has such a ringing, liquid quality. I feel well repaid for my trip by this one experience.”

The male Kirtland's Warbler is bluish gray above and yellow below. It has black streaks on its sides, and a broken white ring above and below the eye. The female has similar markings, but their colors are not as bright.

Breeding and Winter Habitat

Kirtlands Warbler - mom sitting on a nest

The Kirtland’s warbler has a small breeding range. It only nesting the jack pine plains found in northern Michigan, Wisconsin, and parts of southern Ontario. The Kirtland’s warbler spends three to five months in the Great Lakes Region. This rare species is what biologists call a "habitat specialist", because it is very selective about where it chooses to nest and raise young.

The Kirtland’s warbler nests in large areas of dense young jack pine. The trees are generally between five and 15 feet tall.

The females build their nests on the ground and lay four to five eggs. The nest is usually hidden by sedges, grasses or other ground vegetation or structure. The nest is often placed under branches of young jack pine or oak trees.

Between August and September, all the birds fly south to spend the winter months in The Bahamas.

Jack Pine Ecosystem

KW: Jack Pine Plantation

Jack pine plains have very sandy soils. These ecosystems are occupied by species of plants that are adapted to growing on these nutrient poor soils. Trees species include jack pine, northern pin oak and red pine. Jack pine is the most common tree species in these areas.

Prior to European settlers arriving in North America, large wildfires burned thousands of acres of jack pine forest in the northern Great Lakes region on a regular basis.

Most wildfires kill the older jack pine trees and cause millions of seeds to be released. In just a few years, these burned areas are covered by millions of young jack pine trees. Historically, this fire and new forest cycle provided natural habitat for the Kirtland's warbler for thousands of years. 

Large wildfires still occur today, but do not occur as often as they did due to modern fire control. Modern fire control is necessary to protect lives, homes, and private property in northern Michigan.

With fire control, young jack pine stands grow old and too tall for Kirtland’s warbler habitat. By 1970, a loss of breeding habitat and another threat, cowbird parasitism, caused the number of Kirtland’s warblers to decline.

Developing Breeding Habitat

Today, Kirtland’s warbler habitat is created by cutting down and removing old jack pine and then planting young jack pine trees. The US Forest Service, Michigan Department of Natural Resources and US Fish and Wildlife Service manage about 3,400 acres each year to provide habitat for the Kirtland's warbler

Brown-headed Cowbird

KW Habitat: Brown-Headed Cowbird

Cowbirds are mostly found on short-grass prairies with American bison. As people cleared forests for farms and raising livestock, the cowbird found these new open areas met their needs. They quickly moved into these areas - and into Kirtland’s warbler habitat. Cowbirds are nest parasites, meaning they lay their eggs in the nests of other birds to raise and care for their young.

In the early 1970s, researchers found that 70 percent of Kirtland’s warblers’ nests were being impacted by this behavior, reducing the number of Kirtland's warblers.

In an effort to reduce the cowbird’s parasitic behavior, trapping began in 1971. Approximately 60 traps were maintained between April and July, annually removing 4,000 cowbirds which resulted in the number of Kirtland's warbler nests increasing to normal and healthy levels.

Recent field studies have found that cowbird parasitism is not as bad as it used to be. Trapping was suspended in 2018; however, local brown-headed cowbird populations are monitored, and Kirtland’s warbler nests are checked regularly to make sure the parasitism does not become an issue again.

Population

KW Habitat: KW Census ResultsThe Kirtland’s warbler population has grown from 167 pairs in 1987 to 2,245 pairs in 2021. Every year since 2001, the goal of 1,000 pairs of warblers has been exceeded.

In 2019, the US Fish and Wildlife Service removed the Kirtland’s warbler from the list of endangered species. The Kirtland’s warbler population is checked regularly by counting singing males in the late spring. 

Due to the wide-spread range and increasing population, a full census is currently conducted every four years. The last full census was conducted in 2021. The next full census will be conducted in 2025.   

In 2023, 1,011 pairs were counted on the Huron-Manistee National Forests. Nearly all of these birds were found on the Huron National Forest zone; however, in recent years, a few Kirtland’s warblers have been observed on the Manistee National Forest zone.  These birds were observed in suitable habitat areas near state lands that are managed for and occupied by Kirtland’s warblers.

Latest Updates

Kirtland's Warbler Conservation Team

The agencies and others interested in the Kirtland’s warbler continue to share information and work together to conserve the species through the Kirtland’s Warbler Conservation Team. 

Celebrating the Kirtland's Warbler

Kirtland's warbler Calendar Contest an annual contest for youth, launches in January, with a mid-March entry deadline. Artwork is showcased in a full-color, 8.5x11, 18-month calendar, available for a recommended $10 donation at the HMNF Offices (Baldwin, Cadillac, Mio, Oscoda and Wellston)

Kirtland's warbler Festival Roscommon, annually the first full weekend of June. Link is broken, replace with this one: https://www.facebook.com/kirtlandwarblerfestival/



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