March 17, 2006

Bird Experts Question Woodpecker’s Comeback

By Deborah Zabarenko

WASHINGTON (Reuters) - A new analysis of fuzzy video taken in the swamps of Arkansas casts doubt on the ballyhooed comeback of the ivory-billed woodpecker, four bird experts wrote in Friday's edition of the journal Science.

But another team, including the man who made the video, disputed the doubters.

At the heart of the disagreement is whether the video shows an ivory-billed woodpecker or the more common pileated woodpecker, which are of comparable size but have different markings and ways of flying.

"Although we support efforts to find and protect ivory-billed woodpeckers, the video evidence does not demonstrate that the species persists in the United States," said the doubting experts, including David Sibley, artist and author of numerous field guides to for North American birds.

"None of the features described as diagnostic of the ivory-billed woodpecker eliminate a normal pileated woodpecker," they wrote in response to a Science article last year heralding the return of the rare bird, whose last official sighting was in 1944.

Pileated woodpeckers are present over much of the United States, while ivory-billed woodpeckers had been thought extinct for decades. Even before its presumed extinction, the ivory-bill's appearance was so eye-catching that it was nicknamed the "Lord God bird" -- because those who saw it couldn't help exclaiming, "Lord God, what a woodpecker!"

Another group of experts who maintain the bird is back -- including David Luneau, who made the four-second video -- responded in another "comment" in Science.


"Claims that the bird in the Luneau video is a normal pileated woodpecker are based on misrepresentation of a pileated's underwing pattern, interpretation of video artifacts as plumage pattern and inaccurate models of takeoff and flight behavior," this team wrote.

In an e-mail to Reuters on Friday, Luneau questioned the Sibley group's hypothesis that the bird in the video was a pileated woodpecker.

"They have not produced a single video of this relatively common bird doing what they describe," Luneau wrote in answer to a request for comment. "In fact, we have studied many (pileated woodpecker) videos and videos of other birds and we have not found a single case that would confirm either of these assertions. I believe that their hypothesis describes an impossibility."

An early sign that the ivory-bill may have returned was a sighting in 2004 by amateur naturalist Gene Sparling in the Cache River Basin in Arkansas.

Since then, experts from Cornell University and elsewhere have seen the bird too. There have been audio recordings that might be the sound of ivory-billed woodpeckers calling and tapping, and there is the Luneau video, which recorded an ivory-bill's flight.

Science published an analysis of the video that contended that this confirmed the bird's comeback, and ran a color illustration of the bird on its cover last year.

Experts and volunteers are engaged in an intensive search for more signs of the ivory-bill in the swampy Big Woods section of eastern Arkansas.

Definitive proof might include the discovery of a roost tree, where scientists could focus cameras in hopes of a bird sighting. A fragment of eggshell or feathers might also help put questions to rest.