Kirtland’s Warbler

Setophaga kirtlandii

In the birding world, a Kirtland’s warbler sighting is a big deal, and for good reason. The sparrow-size songbird has a very specific range and habitat: In the summer it nests on the ground only in young, dense jack pine forests in or adjacent to the state of Michigan. As the weather turns cold, the bird migrates to the Bahamas and nearby islands and nests in coastal scrub habitat. By the time the Endangered Species Act was signed in the 1970s, “there were less than 200 singing males,” says Patrick Doran, TNC’s associate state director in Michigan. The species faced two threats: the suppression of natural wildfires needed to maintain young tree growth, and predation by the brown-headed cowbird, which deposits its eggs in Kirtland’s warbler nests, creating a competitive environment in which the warbler chicks often lose. “They were getting hammered,” says Doran.

Through habitat management in the form of controlled burns and tree replanting, and through reducing the prevalence of brown-headed cowbirds, Kirtland’s warbler populations have risen dramatically. Delisted in 2019, current estimates suggest some 2,300 breeding pairs are alive today. Still, Doran says, the Kirtland’s warbler is reliant on continued conservation, and its fragility is perhaps what makes sightings so memorable.