Ivory-billed woodpecker extinct after all?
The ivory-billed woodpecker may have faded back into extinction. After more than a year of debate over whether a video taken in an Arkansas swamp really does show a surviving member of the species, a team of ornithologists and bird watchers have weighed in with a "devastating" critique.
In this week's Science1, the team members claim that the 2004 sighting of an ivory-billed woodpecker, thought to have died out at least 60 years ago, is actually of a pileated woodpecker, another large species that is common in the Arkansas woodlands.
"The whole thing is sad," says the team's leader David Sibley, a bird illustrator from Massachusetts. "I wish we were reporting something different. But it is very important for the truth to be out there."
"That is the clearest frame," says Michael Patten, an ornithologist at the University of Oklahoma in Norman and co-author of the critique, "And it is all black on the trailing edge."
Black and white
But the researchers, who claimed to have rediscovered the bird nearly two years ago, are sticking to their guns. "There is black there, but I think it is a shadow or video artefact," says John Fitzpatrick, an ornithologist at Cornell University, Ithaca, New York, who led the project that captured the video.
And after analysing dozens of videos of pileated woodpeckers in flight, Fitzpatrick says that his team is sure that their videotaped bird, seen launching off a tree in woods near the Mississippi River, is not a pileated woodpecker. The critics ignore evidence that the bird is an ivory-billed woodpecker, says Fitzpatrick, and their analysis of woodpecker flight "is just false".
Since their original video sighting2, Fitzpatrick's team of more than two-dozen spotters has searched in vain for the bird. They have a few more weeks before spring forest growth makes scouting impossible.
Next winter, says Fitzpatrick, the search is likely to be reduced, with more reliance on robotic cameras. If still unsuccessful, it may then be called off.
Opinions on the bird's existence have swung back and forth for a year. Last summer, a manuscript concluding that the videotaped bird was not an ivory-billed woodpecker was withdrawn from the journal PLoS Biology, following author disagreement on the evidence.
Around this time Fitzpatrick's team also produced some audio recordings that sounded like the ivory-billed woodpecker's call. But ornithologists now say these recordings are inconclusive.
"The Sibley critique is pretty devastating," says ornithologist Rick Prum of Yale University in New Haven, Connecticut, lead author of the withdrawn manuscript.
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- Sibley D. A., Bevier L. R., Patten M. A.& Elphick C. S. Science, 311 . 1555a (2006).
- Fitzpatrick J. W., Science, 308 . 1460 - 1462 (2005).