New
Ivory-billed Woodpecker Evidence
(This 812th Buffalo
Sunday News
column was first published on October 22, 2006.)
One of the ridiculous things about our modern
society is that first is everything, second is nothing. The Buffalo Bills Super
Bowl records represent a perfect example. Winning four league titles didn't
count.
So it is even in science. The discovery of an
ivory-billed woodpecker, long thought to be extinct, in the Big Woods area of
eastern Arkansas in 2004 made headlines everywhere and has been the talk of
birders ever since. Never mind that the main evidence - a three second video of
a bird disappearing in the distance - has been questioned and that, despite an
extensive search for additional contacts, none have been reported; this was number
one.
In fairness, this woodpecker has virtually
defined the word elusive. Paul Kellogg, whose film of a pair of ivory-bills at
their nest before they were last seen in 1944, once told me how that nest was
discovered. He and other members of a team of Cornell ornithologists led by
Arthur Allen had been searching for the birds for weeks before they came across
the nest. When they finally found it, the nest hole was so close to their base
camp it could almost be seen from there.
I suspect that most readers of this column have
heard of that 2004 ivory-bill discovery. I wonder, however, how many of you
have learned of the more recent evidence of ivory-bills in Florida.
On May 21, 2005, a five member team of
ornithologists from Auburn University and the University of Windsor in Ontario
observed what they thought was an ivory-billed woodpecker in mature swamp
forest along the Choctawhatchee River in Florida. After that initial contact,
assisted by seven other field observers, they spent over a year gathering
evidence related to their discovery.
Unlike the Cornell team working in Arkansas,
this group has gathered a great deal of information that extends this initial
finding. Their evidence is of four forms. First, they carefully recorded 14
sightings that they describe in their technical paper as being birds seen
"well enough to observe the diagnostic shape, plumage pattern, or flight
behavior characteristics" of this species.
The problem with ivory-bill identification is
that it is a near twin to another crow-sized woodpecker: the pileated
woodpecker. The pileated is a far more common species found throughout the
eastern United States and Canada and some western states as well. Here this
species even occasionally visits bird feeders. Both species are largely black
with a "Woody Woodpecker" flaming red crest. (Exception: the crest of
the female ivory-bill is black.) The major difference between the species is in
the amount and pattern of white feathers. The pileated has very little white on
its back, the ivory-bill much more, and this distinction is especially evident
when a bird is seen flying.

Here, for example, is part of the text that
accompanies the field sketch by Tyler Hicks shown here: "I turned and
observed a large black and white woodpecker flying quickly in loon-like fashion
with stiff wing beats. The bird banked and climbed through the canopy offering
binocular views before disappearing. The bird was black with large white wing
patches on the trailing edge of the wing. The wings flashed white on both the
upstroke and down stroke." (Notice the crossed-out grocery list on the
hurriedly used notepad.)
Second, they acquired acoustic evidence using
high quality microphones and digital recorders. In their scientific paper they
document 99 double knocks and 210 "kent" calls. The double "BAM
bam" hammering was compared with Kellogg's recordings, as were the calls.
Great care was taken to differentiate the calls from similar sounds made by
jays, great blue herons, nuthatches and squirrels. In a number of cases the
knocks and calls were recorded at the same time.
Third, recently used nest cavities were
carefully measured and found to be larger than those of pileated woodpeckers.
And fourth, foraging activity was found on types of tree bark not usually attacked
by pileated woodpeckers.
Unfortunately, this group has not been able to
obtain photographic evidence. Thus even their detailed records will remain
suspect. Hopefully, however, the attention their article raises among birders
will draw others to the Florida panhandle to further substantiate this second
event.-- Gerry Rising