The Cornell researchers announced the results at the annual meeting of the American Ornithologists' Union in Santa Barbara, Calif., Aug. 24, and they have invited the public to listen to the calls and knocks on the Web at http://www.birds.cornell.edu .
The recordings reveal sounds that, experts say, are strikingly similar to those made by ivory-billed woodpeckers and provide compelling information that can be added to evidence already gathered of the bird's existence. One of the recordings, from Jan. 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 of Ornithology. "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 yearlong 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 st
Contact: Blaine Friedlander
Cornell University News Service