National Geographic News: NATIONALGEOGRAPHIC.COM/NEWS
 

 

Celebrity Woodpecker Still Extinct, Skeptics Say

James Owen
for National Geographic News
March 16, 2006
 
Last April bird experts hailed the "resurrection"
of the "extinct" ivory-billed woodpecker
. But today some researchers
announced that the big discovery is a case of mistaken identity.

These skeptics cast doubt on a video filmed in a swamp forest in Arkansas (map). The video was presented as proof that the ivory-bill, a bird thought extinct for 50 years, hadn't died out after all.

(Watch the original woodpecker "proof" video.)

The discovery was hailed as the ornithological equivalent of finding Elvis alive. Before the 2004 sighting, the last confirmed sighting of an ivory-bill had been in Louisiana in 1944.

Reopening the debate over the woodpecker's continued existence, a four-person team of researchers is questioning the identity of the bird shown in the blurry video footage.

The challenge appears tomorrow in Science, the journal that also announced the ivory-bill's rediscovery.

The team suggests that the video shows a pileated woodpecker, a smaller but similar-looking species that's relatively widespread in North America.

Led by renowned U.S. bird-watching field-guide author and illustrator David Sibley, the team reanalyzed the video. The footage had been shot in 2004 in the Big Woods region of Arkansas, a 550,000-acre (220,000-hectare) corridor of forested swamps in the Mississippi Delta.

Sibley and his colleagues say that the original researchers misinterpreted the posture of the bird in flight and at rest, and so also misread its size and black-and-white markings.

The skeptics say that the extensive white feathers that seem to be on the bird's back in the video—an ivory-bill characteristic—are actually the underside feathers of a pileated woodpecker's wings.

Based on this interpretation, aspects of the bird's wing patterns are inconsistent with an ivory-bill, the researchers add.

They also say there is not enough data to support the original researchers' claim that they could tell an ivory-bill from a pileated based on the way the bird flies.

Their own video analysis, Sibley's team writes, shows that "all observed features are consistent with a typical pileated woodpecker."

Standing by Their Bird

For their part, the original team that identified the bird as an ivory-bill dismisses the challenge to their finding in a response also published in tomorrow's Science. John Fitzpatrick of the Cornell Lab of Ornithology in Ithaca, New York, led the original team.

Standing by their identification, the researchers argue that their interpretation of the bird's posture is more accurate than Sibley's team's version.

The original posture interpretation, Fitzpatrick's team says, supports their calculations of the extent of white feathers on the bird's back in the video.

They note that white plumage seen on the bird's back doesn't match the pattern of a pileated woodpecker, nor does the absence of black trailing edges on the underwings of the bird in the video.

Fitzpatrick's team concludes that available data on wingspan and flight style does indeed indicate an ivory-billed woodpecker. The researchers also point out that the video was presented to the Arkansas Audubon Society, which voted unanimously to accept it as proof of the bird's existence.

David Luneau, the bird enthusiast who filmed the woodpecker, says Sibley and his colleagues—the skeptics—offer no video evidence to support their contention that some features shown are typical of a pileated woodpecker.

"All of the flight videos of pileateds that we have examined are markedly different in many ways than the bird in the video," Luneau said.

But David Sibley says the burden of proof is on the Cornell-led team. It's up to them, he says, to show that the species is not a pileated woodpecker.

"Nothing in the video is inconsistent with [a] pileated woodpecker, and many of our key points are not refuted by the Cornell team's response," Sibley said. "Therefore the video cannot be proof of the existence of [an ivory-bill]."

Sibley suggests the poor quality of the video may have helped mislead the ornithologists who first studied it.

"The image [of the bird] is extremely small, occupying only a few pixels. It's out of focus, and it's blurred by motion," Sibley added.

Other, unconfirmed sightings of ivory-billed woodpeckers have been reported in recent years. But "without proof, it comes down to a matter of opinion, which is all we've had since the 1940s," Sibley said.

Sound Test

Last year another group of bird experts planned to contest the video evidence. But in August they dropped their challenge after the Cornell lab presented audio recordings taken in the Big Woods region. The audio was suggestive of two ivory-bills rapping on wood.

Richard Prum is an ornithologist at Yale University in New Haven, Connecticut. He said at the time that the sound recordings "provide clear and convincing evidence" that the bird wasn't extinct.

But Sibley said this week, "The Cornell team has always said that the audio evidence is inconclusive. I agree."

According to Luneau, who filmed the bird, there are now "additional interesting sound recordings" which are being analyzed.

Luneau is an associate professor of electronics and computers at the University of Arkansas at Little Rock. He says the results of searches during the fall and winter, when reduced leaf cover makes woodpeckers easier to spot, will be reported soon.

"I am optimistic that there will soon be additional hard evidence," he added.

"The Big Woods of Arkansas is a large area of bottomland forest, much of which is difficult to access," he said. "As John Fitzpatrick said when we began the search in 2004, 'Let's keep in mind that the bird has the upper hand here.'"

Despite their conflicting views, both sets of researchers agree on the need to continue conservation efforts that could benefit the ivory-billed woodpecker.

Whether the ivory-bill is there or not, Sibley said, "The value of saving and restoring the bottomland forest habitat—for other species such as Swainson's warbler, Mississippi kite, and black bear, as well as for our own benefit—is immeasurable."

Free Email News Updates
Sign up for our Inside National Geographic newsletter. Every two weeks we'll send you our top stories and pictures (see sample).

 

© 1996-2008 National Geographic Society. All rights reserved.