[TN-Bird] More Controversy Over Ivory-billed Woodpecker Video
- From: "Charles P. Nicholson" <cpnichol@xxxxxxxxxxxxx>
- To: <tn-bird@xxxxxxxxxxxxx>
- Date: Mon, 19 Mar 2007 20:59:05 -0400
Late last week an article was published in the journal BMC Biology that
questions the identification of the bird in the famous April, 2004 Luneau
video. This article is available at
http://www.biomedcentral.com/1741-7007/5/8/abstract. Following is a brief
discussion of the article from the American Association for the Advancement
of Science ScienceNOW news briefs.
Chuck Nicholson
Norris, TN
Ivory-Billed Imposter?
By Erik Stokstad
ScienceNOW Daily News
15 March 2007
New evidence casts more doubt on the claim that a bird long thought extinct
is still alive and flapping. In 2005, the birding world was riveted by a
report that the majestic ivory-billed woodpecker (Campephilus principalis)
had been definitively spotted in Arkansas (
<http://sciencenow.sciencemag.org/cgi/content/full/2005/428/1> ScienceNOW,
28 April 2005). Since then, some scientists have voiced doubts about the
strength of the evidence. Now a video suggests that the re-discoverers may
have mistaken a large, common woodpecker for the ivory-billed.
The original report of the ivory-billed woodpecker (
<http://www.sciencemag.org/cgi/content/full/308/5727/1460> Science, 3 June
2005, p. 1460) was based on three lines of evidence. First, a grainy,
4-second video filmed by electrical engineer David Luneau of the University
of Arkansas in Little Rock showed a bird resembling an ivory-billed
woodpecker as it flew from a tree in the Cache River National Wildlife
Refuge in eastern Arkansas. Second, several experienced volunteers reported
sightings of a similar bird. And finally, acoustical recorders placed in the
area by the research team, led by John Fitzpatrick of the Cornell Lab of
Ornithology in Ithaca, New York, caught cries and knocking noises like those
made by ivory-billed woodpeckers.
Skeptics were not convinced by the video. In a technical comment last year,
David Sibley of Concord, Massachusetts, and three scientists argued that the
depicted bird could have been a pileated woodpecker (
<http://www.sciencemag.org/cgi/content/abstract/sci;311/5767/1555a> Science,
17 March 2006, p. 1555). Sibley, an author of bird identification books,
noted that the trailing edge of the bird's wings was black, as in a pileated
woodpecker. If the bird were an ivory-billed woodpecker, this edge should
have been white. The Cornell team countered that the black coloring was in
fact part of the background, and that video does show white wings with white
trailing edges. What's more, Fitzpatrick pointed out that the bird in the
Luneau video beat its wings 8.6 times a second, faster than is known for
pileated woodpeckers.
Now, there's new video evidence. Taken by amateur birder David Nolin, the
grainy films capture pileated woodpeckers flying away from the camera, much
like in the ivory-billed video. When J. Martin Collinson, a human geneticist
and avid birder at Aberdeen University in the United Kingdom, analyzed the
videos, he found that some frames showed wings with no black trailing edge
(see photo). "The pileated woodpecker can produce wing patterns that look
more like what you'd expect from an ivory-billed," he concludes. "I'm quite
convinced that the bird in the Luneau video is a pileated woodpecker." In
addition, one of the pileateds beats its wings as fast the bird in the
Luneau video, Collinson reports today in BMC Biology.
Sibley says the new paper backs his argument: "He's documenting for the fist
time how ivory-billed-like a pileated can be." But Fitzpatrick disagrees. He
points out that the pileated woodpecker in Nolin's video quickly slows its
wingbeats, as pileated woodpeckers are known to do. The bird in the Luneau
video, in contrast, continues to fly rapidly for all 4 seconds. As for the
plumage, he says that the Nolin video was not properly processed for
frame-by-frame analysis. "The result is a blur and confusing to decide where
the black and white are," he says.
Who's right? That's a hard call to make--and probably will remain so without
clearer evidence to analyze. "A good photo or video would end this debate
tomorrow," Collinson says.
=================NOTES TO SUBSCRIBER=====================
The TN-Bird Net requires you to SIGN YOUR MESSAGE with
first and last name, CITY (TOWN) and state abbreviation.
You are also required to list the COUNTY in which the birds
you report were seen. The actual DATE OF OBSERVATION should
appear in the first paragraph.
_____________________________________________________________
To post to this mailing list, simply send email to:
tn-bird@xxxxxxxxxxxxxx
_____________________________________________________________
To unsubscribe, send email to:
tn-bird-request@xxxxxxxxxxxxx
with 'unsubscribe' in the Subject field.
______________________________________________________________
TN-Bird Net is owned by the Tennessee Ornithological Society
Neither the society(TOS) nor its moderator(s)
endorse the views or opinions expressed
by the members of this discussion group.
Moderator: Wallace Coffey, Bristol, TN
wallace@xxxxxxxxxxxxxxxxxxx
------------------------------
Assistant Moderator Andy Jones
Cleveland, OH
-------------------------------
Assistant Moderator Dave Worley
Rosedale, VA
__________________________________________________________
Visit the Tennessee Ornithological Society
web site at http://www.tnbirds.org
* * * * * * * * * * * * * * * * * * * * * * * * * * * * *
ARCHIVES
TN-Bird Net Archives at //www.freelists.org/archives/tn-bird/
EXCELLENT MAP RESOURCES
Topographical Maps located at http://topozone.com/find.asp
Tenn.Counties Map at http://www.lib.utexas.edu/maps/states/tennessee3.gif
Aerial photos to complement google maps http://local.live.com
_____________________________________________________________
Other related posts:
