Over the last year there has been much rejoicing over a snippet of videotape that shows a large bird flapping through cypress trees in Arkansas's Big Woods. It is purported to show an ivory-billed woodpecker, a majestic bird thought to be extinct since the 1940s. But well-known ornithologist David Sibley and colleagues at several universities have now described in a technical paper the reasons they believe that the video provides no solid evidence that an ivory-billed was spotted.
"The quality of the video is so poor, there's just not much information to go on," says Sibley.
Crucial to identifying the blurry bird in the video is an understanding of the position of its wings, where white feathers are found. If there is white on the outside of the wings, it should be an ivory-billed. If the white is on the inside of the wing, it is probably a common pileated woodpecker. Sibley believes that the bird in the video is in a position that reveals white beneath the wings, not on the outside.
John Fitzpatrick of Cornell University and the other scientists who originally wrote about the ivory-billed sighting shot back with a their own technical paper, claiming that, among other things, Sibley used inaccurate models of takeoff and flight behavior to interpret the video.
Sibley, author and illustrator of The Sibley Guide to Birds, says that he wishes the bird was indeed the much-sought woodpecker, and hopes that conservation efforts will continue despite his refutation of the sighting. "This bird has so much power," he says. "It's so charismatic, so iconic, that it inspires people. The way that the announcement was received last spring shows how powerful the myth of the ivory-billed woodpecker is. People just latched on to it and started celebrating."
Both sides claim that the other does not address all of the points of their argument.
But all of the good that has come out of this resurgence of interest in an extinct species cannot stand in the way of accurate science, he says.
"We've come up with a reasonable interpretation that explains everything in the video as being a pileated woodpecker," says Sibley. "The burden of proof is on them to show that it is not a pileated, and they haven't done that."
To watch the video of the famous bird, click here:
