**Acknowledgements**

The authors are grateful to a number of collaborators, helping with intense field monitoring of owls in years 1989–1994, namely especially to †Róbert Leščinský, Gabriel Lešinský, Róbert Olejár, Roman Rajštetter, Karol Takáč and many others, during period 2017–2021 we are grateful first of all to field collaborators Róbert Olejár, Karol Takáč and Ján Tencer.
