Meet the Kirtland’s warbler, a rare bird that summers on the Michigan peninsula and almost nowhere else on earth.
“There are fewer than 5,000 Kirtland’s warblers (about 2,000 males on territories) remaining,” Kricher said. “They nest on the ground only in young jack pine forests so they require highly managed habitat that is burned sufficiently frequently that the small trees they require will be there for them.
“Jack pine forests have migrated north with the end of glaciation, and there are large tracts of mature jack pine in the north and central United States, but they are all unsuitable for Kirtland’s warblers. Young and recently burned jack pine is rare and thus must be created for them.”
Indeed, it’s the bird’s reliance on such habitat that humans now must create that interests Kricher. “I will focus on this species in my courses on ecology and ornithology as examples of conservation action that works to maintain a highly threatened species.
“In the past, when this species evolved, there must have been much more frequent burning presumably due to naturally set (lightning initiated) fires,” Kricher said. ” But no one really knows for sure how these birds evolved their odd ecology. What is clear is that they inhabit scrubby areas both to breed and to winter.”
Kirtland’s warblers winter in the Bahamas. Despite Kricher’s previous work in studying tropical and neo-tropical ecology, he had not observed the birds there. He said the tiny warblers are quite popular in Michigan.
“Because the warblers bring tourists in the form of bird enthusiasts, the tracts that are maintained by controlled burns are not at all controversial among the local residents. Banners line the road through a town near where the Kirtland’s nests,” he said. “Locals love these birds. They bring in some income, at least in spring and early summer, when the warblers are present.”