Ivory-bill Acoustics

March 2007

The search for the ivory-bill has been both a visual and acoustic endeavor. In 1942 James Tanner wrote: "All the ivory-bills that I have ever seen I located first by hearing them call and then going to them." 

Since the beginning of our intensive search efforts in 2004 we have been using autonomous recording units (ARUs) to record possible sounds of ivory-bills. Capturing the sounds, however, is only half of the acoustic monitoring process. The other half is finding the important sounds among thousands of hours of recordings and then interpreting what we've found. Through this process we have learned a lot about sound analysis and the potential sounds of the forest that can trick one into thinking that an ivory-bill is calling or drumming.

Here we give you a behind-the-scenes look (listen) at what we are discovering, ranging from ivory-bill sound-alikes to enigmatic sounds that are consistent with known ivory-bill vocalizations and Campephilus double knocks.