Top Birder Challenges Reports of Long-Lost Woodpecker
http://www.nytimes.com/2006/03/17/science/17bird.html
The ivory-billed woodpecker? That's the bird that
went extinct, and was rediscovered, and then there
was some argument but it's all settled now and the
great creature lives, elusively, in an Arkansas swamp,
with a chunk of federal money to keep it comfortable. Right?
Maybe not. The nation's best known birder, David A. Sibley,
whose book "The Sibley Guide to Birds" is a bible for field
identification, has decided that the happy ending is
too good to be true.
Mr. Sibley, a soft-spoken, attention-avoiding writer and
illustrator of many other bird books, says in an article
being published today in Science that a blurry videotape
that was the strongest evidence of the woodpecker's
continued existence does not show an ivory bill at all.
He and three colleagues write that the bird on the tape
was almost certainly a common pileated woodpecker and
that there is simply no conclusive evidence that the
ivory bill has escaped extinction.
The videotape, which has been called an ornithological
Zapruder film, was made on April 25, 2004, by M. David Luneau Jr.,
an engineering professor at the University of Arkansas,
Little Rock. Professor Luneau had joined a search led by
the Cornell Lab of Ornithology to gather more evidence
after two serious birders reported seeing the ivory bill
fly in front of their canoe.
Along with sightings, the tape was the centerpiece of
a spring 2005 paper, also in Science, that caused
jubilation among conservationists and birders and
prompted the federal government to commit $10 million
for ivory bill conservation.
The majestic ivory bill, the largest woodpecker in
the United States, had been a poignant example of
extinction from the last confirmed sighting in 1944
until the report of the rediscovery, when it quickly
became a symbol of hope, embraced by birders and the public.
Mr. Sibley said he went public with his critique reluctantly.
But, he added: "I think that this identification is wrong,
and I feel that I'm obligated to correct that.
Conservation has to be based on science."
Dr. John W. Fitzpatrick, director of the Cornell Lab of
Ornithology (www.birds.cornell.edu/ivory), said that he
could not agree more about the importance of scientific
evidence and that he continued to believe that the video
clearly showed an ivory bill.
Dr. Fitzpatrick and his colleagues have a rebuttal to the
critique in the same issue of Science. Although the critique
is "carefully reasoned," it has "technical errors,"
he elaborated in an interview, adding, " "Their description
of how a bird flies is incorrect."
"Really what they're doing is declaring that their
view of the video is that it is not definitive,"
Dr. Fitzpatrick said. "And that's almost by definition
true. If there are a few people who say,
'I don't know if I can tell what that is,'
then it's not definitive."
But, he said, the accumulated evidence of sightings,
sound recordings and the tape are enough to show that
at least one ivory-billed woodpecker was in the
Cache River National Wildlife Refuge in the winter of 2004.
The argument is a classic scientific dispute, and if
the bird were not such a romantic creature, if birders
were not fanatical about correct identification and if
a pot of federal money were not involved, the back and
forth would be unremarkable.
The paper comes after nearly two years of extensive
searching in Arkansas by Cornell teams for a clear
photograph or videotape. In that time, disagreement
has been bubbling among birders and ornithologists in
Internet discussions.
And yet the rediscovery has had broad public acceptance.
In fact, the three men who first reported the sighting
in Arkansas in 2004, Eugene Sparling, Bobby Harrison and
Tim Gallagher, will be honored tomorrow by the
Explorers Club in New York.
In this context, the paper from Mr. Sibley, Louis R. Bevier
of Colby College in Maine, Michael A. Patten of the
University of Oklahoma and Chris S. Elphick of the
University of Connecticut is a loud public salvo on
behalf of those who believe that the claims for the
bird's continued existence go beyond the evidence.
Among them is Kenn Kaufman, author of "Birds of North America"
and a series of other nature guides. Mr. Kaufman said his
initial doubts about the conclusiveness of the video
had given way to a conviction that the bird was
a pileated woodpecker.
"My best guess is that Gallagher and Harrison
made a mistake," Mr. Kaufman said. "They made an
honest mistake. And everything just sort of cascaded
on from that."
The details of the disagreement are downright Talmudic.
But simply put, the question is whether the blurry
white patches visible in the tape are on the top of
ivory bill wings or the bottom of pileated wings.
The ivory bill is a larger bird, up to almost
21 inches long, but the lowest estimate of its length
and the upper limit of pileated length overlap at
about 19 inches.
Mr. Sibley and his co-authors, along with Mr. Kaufman
and other critics, say the viewer is most likely seeing
the underside of pileated wings on the upstroke.
They do not say the pileated case is airtight,
but argue that the images can not be counted as
proof of an ivory bill.
The Cornell rebuttal in the same issue — by Dr. Fitzpatrick,
Martjan Lammertink of the Cornell Lab and the
University of Amsterdam, Kenneth Rosenberg of the lab
and Mr. Luneau — presents evidence that the viewer
is indeed looking at the back of an ivory bill as it
flies away.
Other ornithologists not involved in either paper had mixed reactions.
Jeffrey R. Walters, a woodpecker specialist at Virginia
Polytechnic Institute and State University who was one
of the scientists who reviewed the original report of
the rediscovery for Science before publication, said he
thought that the evidence that the tape showed an ivory bill was
better, but that "I think it's fair to say that it's not definitive."
J. Michael Reed at Tufts University, who had no role
in the critique but is a friend of Dr. Elphick, said
that he had been impressed by the original Science paper
but that given the current dialogue, "the burden of proof
is to demonstrate that it's an ivory-billed woodpecker, and I
don't think they've done it."
All parties are united in the hope that the bird,
whether or not it has been captured on videotape,
is alive somewhere in the swamps. As Mr. Kaufman said,
"If somebody came up with decent video of an ivory bill
tomorrow, I would go out and dance in the streets."
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