Kirtland's Warbler

Kirtland's Warbler

About the Kirtland's Warbler

Kirtland's warbler is a wood warbler found primarily in Michigan's upper and lower peninsulas. It also breeds sporadically in Wisconsin and Ontario Canada. It is one of the rarest of the wood warblers because it strictly nests in grasses and shrubs growing under forests of young (5-20 year old) Jack pine trees. The birds winter in the Bahamas and the Turks and Caicos Islands. 

Their dependence on specialized habitat likely means that Kirtland's warblers have always been rare.  Until 1996 the bird was believed to nest only within a 60-mile radius of the first Kirtland's nest found (in 1903). Kirtland's numbers are thought to have reached an unknown peak around 1900 when Jack pine forest acreage was at its zenith. Modern forest fire protection and suppression which disrupted the lifecycle of the Jack pine led to rapid declines in Jack pine acreage and Kirtland's warblers numbers. In 1973 with only about 200 singing males remaining it was listed as endangered.

Why NFWF Intervened

Kirtland's warbler recovery efforts have a long history. Between 1957 and 1962 the U.S. Forest Service and Michigan Department of Natural Resources created four specially-managed areas for the bird. More land was set aside in the 1970s and 1990s eventually totaling more than 150000 acres logged burned seeded and planted on a rotational basis. Unfortunately habitat was not the only problem.

Brown-headed cowbirds which lay their eggs in other birds' nests and whose chicks out-compete their nest-mates were discovered to be parasitizing a significant percentage of Kirtland's warbler nests. Cowbird trapping began in 1972 and continues to this day. Finally a partnership was formed with organizations in the Bahamas to protect the song-bird's wintering grounds and control feral cats.

With the combined support from state and federal agencies Kirtland's populations showed a remarkable increase. By 2013 it was estimated at 4000 individuals.

Our Goal

Kirtland's warblers are unquestionably a conservation-reliant species. Without both active forest management and control of cowbirds the bird would likely disappear.  To help advance Kirtland's conservation NFWF proposed a strategy for the development of a Kirtland's warbler partnership that incorporated four major elements:  1) a "Friends" group for Kirtland's warbler 2) a long-term stable funding source to support cowbird control 3) formal commitments to continue management and 4) a partnership coordinator.

Accomplishments

  1. Federal and state agencies have signed an agreement to continue managing Jack pine forests on state-owned/-managed lands;
  2. Both the Kirtland's Warbler Alliance a public-private partnership and the Kirtland's Warbler Designated Fund an endowment have been established; and
  3. Our partners led by Huron Pines and the U.S. Fish and Wildlife service have raised $1 million which will be used to support cowbird control measures in future years.

Conclusion

With more than 1000 Kirtland's nesting pairs in Michigan the bird has recovered to the point where it has met the biological criteria for removal from the Endangered Species List.

Kirtland's Warbler Credit: Joel Trick/USFWS