Thursday, July 2, 2009

Cerulean Warbler Success: Long-Term Conservation at Work

When surveys this spring confirmed Cerulean warblers singing in north Georgia forest openings created to attract them, the news was music to Nathan Klaus’ ears. It was also confirmation for Klaus and others that some conservation efforts take years to see results.

Klaus, a senior wildlife biologist with the Georgia Department of Natural Resources, and U.S. Forest Service biologist Jim Wentworth had patches of trees cut on 20 sites in two Chattahoochee National Forest areas in the winter of 2004-2005. Some Cerulean warblers were documented at a few sites soon after. But it wasn’t until this spring – four years later – that the birds were reported using seven of 10 cuts along Ivy Log Gap near Blairsville, one of the two areas targeted. No Cerulean warblers had been heard or seen at the sites before.

“This is the first real glimmer of hope we have to turn around that species,” Klaus said.

The glimmer of hope for the continent’s fastest declining warbler comes from far-searching research. To accommodate breeding requirements for these small, sky-blue birds state-listed as rare in Georgia, Klaus and Wentworth, working with the Audubon Society’s Important Bird Areas program, wanted to create a diverse hardwood canopy. Their aim: Mimic the forest canopy conditions -- including small gaps -- found in mature forests and needed by the warblers, instead of the more prevalent younger tree stands that lack a diverse canopy.

But the biologists suspected the new growth needed years, maybe even decades before it would become good habitat. Klaus, Wentworth and others, including volunteers, surveyed the sites for three years before – to make sure none had Cerulean warblers – and made plans to monitor them for at least five years after the cuts.

The long-range look is critical to many conservation projects. Examples vary from surveying sea turtle nests, done daily along Georgia’s coast since 1989, to restoring canebrakes in the Piedmont region. Years of data yield more effective recovery plans and clearer measures of management impacts.

But such science poses challenges. Land ownership can change. Careers, too. Researchers must plan and set sample sizes according to what they expect. They and their organizations also must be committed to this longer vision, said Klaus, who works with the Nongame Conservation Section of the DNR’s Wildlife Resources Division.

The payback can be sizable, however. “There’s an opportunity to learn how the landscape works,” he said. “Not all solutions are quick or easy, and understanding the issue may take time and patience.”

The work along Ivy Log Gap will likely spur further research into forest cuts to support Cerulean warblers, found in only two populations in Georgia. Meanwhile, the lack of Ceruleans so far at the other test area, Duncan Ridge on Coopers Creek Wildlife Management Area, may reveal the inability to draw these birds to forests where they have never been found. Ivy Log Gap has long been a haven for the species, although not at the test sites.

Klaus is confident that Cerulean warblers will continue to use the Ivy Log Gap sites. But he may check the Duncan Ridge areas for another five years, or longer.

And after that? “I’ll probably check in on this site occasionally for the rest of my career,” he said. “Forests change very slowly over time. Twenty or 30 years is a relatively short time in the life of an oak forest.”

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