Protecting the Endangered Kirtland's Warbler and Developing Conservation Capacity in The Bahamas
The Kirtland's Warbler, one of North America's most endangered migrant songbirds, has been the focus of intensive federal and state conservation efforts. Long a mystery and subject of controversy, the winter habitat of the Kirtland's Warbler in The Bahamas was recently described by Forest Service scientists and cooperators. Their findings indicate that the warbler uses human-disturbed broad-leaved habitats in the early stages of succession (6-28 years after disturbance). These disturbed sites often had an abundance of fruit for the warblers to eat. Warblers abandoned sites as fruit production ceased and shifted to new sites where fruit was more abundant. As sites mature production of fruits consumed by the warbler decreases. Thus project results indicate that simply protecting parcels of land in which succession is allowed to run its course in the absence of disturbance will likely be insufficient to provide winter habitat for the warbler in the future.
The reliance of wintering Kirtland's Warblers on early-successional habitats poses a challenge for conservation of the warbler's winter habitat, given the need for periodic disturbance to produce habitat. As habitat is lost to development less area is available for natural disturbance to produce warbler habitat. Therefore the warbler will require re-occurring disturbances from humans to provide appropriate winter habitat. Forest Service scientists are working with goat farmers, utility companies, and other land owners to encourage re-occurring disturbances that benefit the warbler. Warblers are often abundant on goat farms where the goats consume plants that compete with the warbler's fruit plants while ignoring fruit plants important to the warbler. In addition, the warblers have been found to use utility corridors where utility companies periodically cut or plow the vegetation to reduce growth and contact with utility lines. Some of the prime Kirtland's fruit plants respond well to periodic cutting, mowing or even bulldozing and can re-sprout and fruit shortly thereafter suggesting that they may thrive not only in utility corridors, but also in boundary lines and fire breaks. By harnessing these pre-existing disturbances to better favor Kirtland's fruit plants it should be possible to implement cost effective management for the warbler on private lands in The Bahamas.
In addition to improving warbler habitat, the project's research is also developing human resources in The Bahamas. Student interns from the College of The Bahamas assist researchers for a seven month winter field season, then migrate with the birds to Michigan where they work with the breeding warbler and other wildlife projects with support provided by The Huron and Manistee National Forests and The Nature Conservancy. Breeding ground management has increased the species population from about 400 in the 1970s to 3000 today. Following successful completion of the second winter field season, each student intern is awarded funding from The Nature Conservancy, which enables them to complete their bachelor's degrees in biology and natural resource management in the U.S. Eight students have been supported for bachelors degrees and two of these students have successfully completed master's degrees. Two of the Bahamian students have returned home to The Bahamas and currently work for conservation organizations. Thus the project strengthens conservation capacity and provides Bahamians with the training and research results provide tools to implement conservation management for the Kirtland's Warbler on its wintering grounds.
Forest Service Partners