Watch a video of the Kirtland’s warbler in its wintering habitat in the Bahamas.
The Jack Pine forests of northern lower Michigan boast a rare and beautiful species of bird, the Kirtland’s warbler. To catch a glimpse of the bird with its dark striped, bluish gray back atop its yellow belly and speckled sides is as moving as hearing its unique song. For those who have followed the history of the bird, that song is a reminder that this little bird came close to being tuned out.
The Kirtland’s warbler has made its summer home and breeding grounds in the Jack Pine Forests of Michigan since before the 1900’s.To escape the frigid Michigan winters, the bird travels to The Bahamas for eight months until returning in the late spring. Favoring young Jack Pine and dense canopy cover, the bird finds Michigan suitable to its nesting habits. According to Les Line in Audubon’s March 2004 issue, the warbler once favored the area because its natural wildfires could occur unchecked by human interference. A necessity to the youth of the trees, the fires clear the area of other plant life, regenerate the soil, and force the pine to release its seeds making room for new Jack Pine growth.
The natural cycle of the forests so favored by the warbler could not remain untouched forever. Human interference and parasite species proved daunting to their habitat and life-cycle. The young pines provide a suitable home for the bird at about age 6 and remain suitable for about 10 years. Modern fire control measures began changing natural regeneration and young growth and, “by the 1950’s warbler habitat had become scarce." In addition to human interference, the brown-headed cowbird which lays its eggs in the nest of the Kirtland's warbler, parasitized the nest. As a result the successful fledgling per nests dropped to less than one. The all time lowest population totaled a mere 201 in 1971.
Starting in 1957 action was taken to preserve the Michigan habitat of the Kirtland's warbler. According to Harold F. Mayfield’s 1992 article in The Birds of North America, the total area owned today by the state of Michigan and set aside for the Kirtland’s warbler is 51,700 ha in 16 areas. Controlled fires, logging practices and methods to stimulate new growth through fire simulation techniques have begun to restore the warbler’s population. In addition major action has been taken to remove the cowbird from warbler’s nesting areas. In the latest study of 51 nests, rearchers found no trace of the cowbird.
The restoration of the Kirtland’s Warbler has been so successful that from 2002 to 2005 alone, the total Michigan population increased by almost 400 for a Michigan total of 1,415 in 2005, (2002-2005 Census Results).
This article was written by Amber Hursh, External Affairs Intern.