Scientist Challenges Ivory-Billed Woodpecker Sighting
Thursday, March 15th 2007, 10:49 am
By: News On 6
LONDON (AP) _ A Scottish scientist says American bird experts may have been wrong when they concluded that the ivory-billed woodpecker, thought to be extinct, might have survived.
In an article published Wednesday in the journal BMC Biology, University of Aberdeen geneticist Martin Collinson disputed whether a video shot by an Arkansas scientist showed the ivory-billed woodpecker.
Collinson, a passionate birder, analyzed the Arkansas video frame by frame and compared it with that of a pileated woodpecker, which is a related species with similar black-and-white plumage. His study suggested it was not possible to be certain that the bird in the video was the ivory-billed woodpecker.
``The bird in the Arkansas video is best regarded as not fully identified, and is probably a pileated woodpecker,'' Collinson wrote.
The last confirmed sighting of the ivory-billed woodpecker in North America was in 1944. Researchers believed the species was extinct until 2004, when a kayaker is said to have spotted one in eastern Arkansas. Since then, there have been several sightings, and a videotape shot by David Luneau, an electronics professor at the University of Arkansas at Little Rock, was released.
That video was seen as evidence of the bird that seemed to have vanished after logging destroyed its habitat. But the poor quality of the video led to questions _ and a lingering dispute about its existence.
A research team headed by David A. Sibley of Concord, Mass., wrote in the journal Science last year that the quality of the video is not good enough to clearly see the ivory-billed woodpecker's distinctive white stripes on its back. Also, the large amounts of white seen while the bird is flying can be accounted for by the underside of the wings of a pileated woodpecker, the researchers wrote.
Collinson said he thought it was possible to spot the pileated woodpecker's distinctive black trailing wing edges in the Arkansas video. The trailing edges of the ivory-billed woodpecker's wings are white.
Though it was believed the pileated woodpecker's wings beat more slowly than the 8.6 beats per second captured on Luneau's video, Collinson concluded the pileated woodpecker's wings could beat that fast, at least for short flights.
Other scientists disputed Collinson's findings.
John Fitzpatrick, a director of Cornell University's Laboratory of Ornithology, said that different formats of the footage result in ``comparing apples to oranges.'' Fitzpatrick said Collinson's evidence about similarities in the birds' coloring, wing patterns and flight patterns are skewed as a result.
Fitzpatrick remains ``convinced that the Luneau video is inconsistent in every respect with pileated woodpecker.''
``We have yet to see even a single video of pileated woodpecker that matches the (Arkansas) video. Show us one and I'll change my mind,'' he said. ``Nobody can do it. ``