New Sounds Released in Search for Ivory-billed Woodpecker

*Cornell researchers say recordings offer further evidence of
ivory-bills in Arkansas*

FOR RELEASE AUGUST 24, 2005, 1:30 P.M. EST

Contact: Constance Bruce, (607) 254-2491, clb82@cornell.edu

ITHACA, NY\--After analyzing more than 18,000 hours of recordings from
the swampy forests of eastern Arkansas, researchers from the Cornell
Laboratory of Ornithology at Cornell University say they have found
sounds offering further evidence for the existence of the Ivory-billed
Woodpecker. The sounds were recorded in the same area where the species
was rediscovered in 2004.

The researchers announced the results at the annual meeting of the
American Ornithologists' Union in Santa Barbara, Calif., on Aug. 24,
2005, and invited the public to listen to the calls and knocks on the
Web at [www.birds.cornell.edu](http://www.birds.cornell.edu/). The
sounds are strikingly similar to those made by ivory-billed woodpeckers,
the researchers said. One of the recordings, from January 24, 2005,
captured a distant double knock, "Bam bam!" followed by a similar and
much closer double knock 3.5 seconds later---possibly the drumming
displays of two ivory-billed woodpeckers communicating with one another
by rapping on trees.

"I immediately felt a thrill of excitement the first time I heard that
recording," said Russell Charif, a bioacoustics researcher at the
Cornell Lab. "It is the best tangible evidence so far that there could
be more than one ivory-bill in the area." Only a single bird at a time
was documented through sightings and video footage during a year-long
search of the area in 2004-05. Whether more than one bird exists is
still a big question, Charif said, but quantitative analyses of the most
promising sounds indicate a high probability that they were made by
ivory-billed woodpeckers.

The sounds were recorded on autonomous recording units (ARUs) designed
by the Cornell Lab and strapped to trees in the swamp. More than 150
sites were monitored in the half-million-acre "Big Woods" of Arkansas.

After eliminating thousands of noises from gunshots and other sources,
the researchers found about 100 double knocks that bear a strong
resemblance to the display drumming of the ivory-bill's closest
relatives. The sounds were clustered around certain recording locations
at certain times of day---a pattern that would not be expected if they
had been produced by random noises.

Then ARUs also recorded nasal tooting calls similar to those of
ivory-billed woodpeckers. Charif said blue jays are notorious vocal
mimics that sometimes utter calls like those of ivory-bills. However, he
added, a

*(more)*

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sophisticated acoustic classification program categorized nearly all of
the unknown calls from Arkansas as most similar to ivory-billed
woodpecker recordings. None matched up with "tooting" calls of blue jays
from the Lab's audio collection, but the researchers say they cannot
rule out blue jays until they analyze more variants of the calls.

"We're excited and encouraged by the acoustic analysis," said Dr. John
Fitzpatrick, director of the Cornell Lab of Ornithology. "These sounds
give us additional hope that a few ivory-billed woodpeckers do live in
the White River and Cache River region. But this species is still on the
verge of extinction and huge mysteries remain to be solved. Certainly,
we have a lot more work to do before we know enough to determine its
population size, let alone ensure its survival."

A team led by the Cornell Lab of Ornithology, The Nature Conservancy,
the U.S. Fish and Wildlife Service, the Arkansas Game and Fish
Commission, and other partners, will renew search efforts in the Big
Woods beginning Nov. 1.