LISTENING TO DIVING BIRDS

摘要

The paper concerns acoustic studies of diving little auks (small Arctic birds). It presents the inverted echosounding and noise measurements performed by the Autonomous Hydroacoustic System (AHS) deployed in the Spitsbergen fjord close to the bird colony. The echosounder records (130 kHz) are used to determine the depth distribution of dives and the dive traces, whereas the noise signals (0.4-12.5 kHz) are used to find spectral characteristics of diving birds and to discern their sounds from other sources (ships, rain, wind, etc.). Main conclusions: the birds dive to the depth of up to 34 m and their noise signal is characterised by a narrow intensive peaks with a maximum at 1-4 kHz.