Listening for the Ivory-bill

April 2005

Audio recordings turned up calls and double knocks. Were they made by Ivory-billed Woodpeckers? Follow the links next to the images below to listen to recently analyzed recordings and read the opinions of Lab experts.

Ivory-billed Woodpeckers are elusive and difficult to see in the dense, swampy woods where they live. In 2004-05, a team of more than 50 people from the Cornell Lab of Ornithology, The Nature Conservancy, and other partner organizations, spent about 15,000 hours searching 38,500 acres of the Big Woods of Arkansas. Individual searchers encountered an Ivory-billed Woodpecker briefly at least seven times. Additionally, David Luneau, a professor from the University of Arkansas, captured a few seconds of video footage of an Ivory-billed Woodpecker taking off from a tree. 

During the search, a bioacoustics team from the Cornell Lab of Ornithology deployed 24 autonomous recording units in the Big Woods of Arkansas. They rotated these units to monitor 153 different sites, allowing them to cover larger areas for longer periods of time than would have been possible otherwise.

After sifting through more than 18,000 hours of audio recordings, researchers have found a number of intriguing sounds they believe could have been made by Ivory-billed Woodpeckers. 

Join the Cornell team as they document sounds from the Big Woods and gather intriguing clues that add further evidence of the elusive Ivory-billed Woodpecker.

--The Technology Behind the Recordings
Learn how the search team gathered and analyzed more than 17,000 hours of audio recordings.

--The “Double Knock on Wood”

The Ivory-billed Woodpecker is the only bird in the United States that has a double-rap display drum. Listen to the sounds to see if you think they were made by Ivory-billed Woodpeckers.

--The “Kent” Calls

Compare nasal tooting calls from the Big Woods with recordings of Ivory-billed Woodpeckers recorded in 1935. Listen to the sounds of ivory-bill imposters—Blue Jays.

-- What Do the Experts Think?

Read results of the bioacoustics analysis by Cornell Lab of Ornithology researchers.

--The Blue Jay Challenge

Have you heard Blue Jays making calls that sound like those of Ivory-billed Woodpeckers? Send your recordings to the Cornell Lab of Ornithology for use in the next round of analysis!