Acoustic ecology of tawny owl (Stria aluco) in the Greek Rhodope Mountains using passive acoustic monitoring methods

Passive acoustic monitoring is a wildlife monitoring method used especially for the study of vocally active species which are difficult to observe directly. The tawny owl (Strix aluco, Linnaeus 1758) is such a species, and has not been previously studied in Greece. The aim of the study was to provide a first insight into the species' acoustic ecology in the Rhodope Mountains by describing its calling activity at four sites over a period of 3-6 months, and to examine possible correlation with natural and climatic parameters. Based on 24,937 calls, we report a significant increase in the number of calls per night (18:00 pm to 9:00 am) as the length of the night increased, as well as a negative relation with wind speed. We did not observe a relationship between calling frequency and the phase of the moon.