Fig. 4. Acoustically derived estimates of songbird arrival to breeding grounds and relationship to snow-free dates.

(A) Songbird community mean arrival dates to their breeding grounds near TLFS, Alaska over a 5-year period (2010–2014) using supervised and unsupervised bioacoustic approaches compared to traditional avian surveys. SE bars reflect averages across four recording sites for acoustically derived estimates. (B) Songbird community arrival dates for at each site over a 5-year period (2010–2014) estimated from supervised and unsupervised bioacoustics approaches compared to the date on which the landscape surrounding the recording unit fell below 10% snow coverage.