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		Nature Conservancy Magazine: Spring 2006 Nature Conservancy Magazine Tallgrass Prairie New Perspective on Parks Kirtland's Warbler Grand Isle, Louisiana Nature Stories Podcast Nature Landmarks Nature Books Nature Travel Nature Preserves Subscribe

Tracking Down the Kirtland's Warbler

BBXR (Blue, Blue, Metal, Red)-banded Kirtland's Warbler   Unbanded Kirtland's Warbler   Unbanded Kirtland's Warbler BBXR (Blue, Blue, Metal, Red)-banded Kirtland's Warbler All photos © Dave Currie

For a century the endangered Kirtland’s warbler—famous for broadcasting a loud, distinctive song from the top of jack pines each spring in Michigan—has stymied ornithologists looking for its wintering grounds in the Bahamas. The bird becomes something of a recluse in its southern range, where only about 200 individuals have been spotted since 1879.

Collectors, renowned ornithologists, conservationists, and Kirtland’s warbler experts have all searched for the bird with limited success. James Bond, a curator at Philadelphia's Academy of Natural Sciences for 50 years, spent about 100 days looking for the warbler in the late 1930s and found only one. 

"Unless the birds are concentrated in some locality or in some unusual habitat not yet discovered, the prospect of finding them is discouraging indeed," wrote ornithologist Harold Mayfield in 1950.

Reports of the warbler trickled in, keeping alive hopes for the long-awaited breakthrough discovery. Island residents and birdwatchers from Florida spotted the bird every year from 1959 through the 1960s.

But success eluded Wisconsin ornithologist John T. Emlen Jr. He spent 500 hours combing measured tracts on Grand Bahama and Andros from 1968 to 1971 and found no warblers. Another researcher, Bruce Radabaugh, spent 800 hours playing recordings of the warbler's song on 11 islands in 1974 and sighted only one.

To be sure, many of the challenges facing scientists studying the warbler are shared by investigators of other migratory songbirds. Most birds migrate at night, not during the day, and are unlikely to congregate while migrating, so they are difficult to see. Most also stop singing when they are no longer trying to attract a mate or defend a nesting territory, so they are a challenge to recognize by ear.

And many of those records, it should be noted, came at a time when there weren't a lot of warblers. Annual censuses in Michigan tallied as few as 167 singing males as recently as 1987. Population numbers have improved since. Census takers recorded 1,348 singing males in 2004 and 1,415 in 2005, the highest total since the first count in 1951. But that hasn't made each warbler easier to find.

—Chuck Hagner