Vocal activity of Tengmalm’s owls (Aegolius funereus) in the Middle Volga

Abstract

The article considers the recordings of the vocalization of Tengmalm’s owl in the Middle Volga were obtained using dictaphones. The first calls of Tengmalm’s owl were recorded 1 h 30 min after sunset. The last calls were recorded 3 h 45 min before sunrise. The longest vocalization interval was observed at night. The frequency range of male calls is 550-950 Hz. Continuous vocal activity in certain periods of the day lasted from 3 min to 27 min. Vocal activity were observed in the temperature range from -5 to +6°C. Calls were recorded at wind strength from 1 to 3 m/s, at cloud cover from 10 to 30%, at pressure from 750 to 764 mm Hg.