The dense vegetation of the marsh makes it the perfect habitat for secretive birds such as bitterns and rails, but it also makes it hard to find them (unlike the marsh’s bald eagles, which are easy to spot soaring above).

It is much easier to hear these birds as they call to each other from out of sight. Mike Coulter, supported by a team of volunteers, has deployed automated audio recorders throughout the marsh landscape to record sounds that we then run through Cornell University Ornithology Lab’s BirdNet AI to detect the sounds made by secretive species. BirdNet produces a lot of false positives (dog barks that get flagged as bittern calls, for example), meaning that Mike and his team of volunteers need to then review each “hit” to confirm that it is an actual bird.

Learn more about the Birds of the Great Marsh project in this video recording of Mike’s presentation for Valley Forge Audubon.