2021 Acoustic Monitoring Report

We operated the Bitterroot array of microphones to study passerine migration by recording and analyzing nocturnal flight calls (NFCs). While we pioneered this array, the largest ever built for NFC monitoring, we also simultaneously developed software, called Vesper, that allows us and others to make sense of terabytes of audio files. Due to the lack of historical and current NFC monitoring in the Intermountain West, we face challenges identifying calls, but the absence of information also offers a chance for discoveries.