Tracking owls with cell phones.
Working the night shift can be lonely, especially deep in the forest, so it’s no wonder owls respond when they hear a fellow owl hoot in the distance. That behavior has been a big help to the Maine Audubon volunteers who monitor the state’s owl population. For the past several years, they’ve carried CD players into the woods, played recorded owl noises, and taken notes on the responses they hear. But during this year’s survey period in March and April, Dale Joachim, the Martin Luther King Jr. Visiting Professor at the MIT Media Lab, will send some of the volunteers out with cell phones that can both emit sounds and record them.
A computer in Joachim’s Owl Project lab is programmed to call the phones, which will transmit the sounds of various owl species via speakers. Using four directional microphones arranged in a pyramid, the same phones will then capture the responding hoots. Back at the Media Lab, the computer will process the recorded sounds to determine the number of distinct owl voices and the directions from which they emanated.
An electrical engineer with a background in speech processing, Joachim hopes that cell-phone technology will eventually provide more-sophisticated data for studies of owl vocalizations, such as information about the birds’ hearing range or their response rates under particular weather conditions. But another goal of the Owl Project is to see how well data collected by people, in this case the note-taking volunteers in Maine, corresponds with that collected by machines. “We have planned the collaboration very closely so settings of their surveys and ours can be compared,” says Joachim.
Armchair owlers will be able to hear recordings from the spring survey online at owlproject.media.mit.edu, then submit their observations about the number and type of owls they think they hear. Joachim, who is also interested in the study of collective observation, hopes to review the conclusions drawn by the Maine Audubon volunteers, the computer, and the online participants and compare them for accuracy.