| Abstract [eng] |
The Eurasian Pygmy Owl (Glaucidium passerinum L.) is a widely distributed and protected species all over its distribution range. There are special protected areas in EU countries, where species’ monitoring is carried out under EU Birds directive. However, there is a lack in quantitative data on species macrohabitat, habitat preferences, and vocalization conditions. This thesis addresses these issues. The Eurasian Pygmy Owl macrohabitats – squares of 200 ha, where territorial owls were located in 2005 - 2011 – were compared with randomly selected 200 ha squares. It was ascertained that the Pygmy Owl prefers forest (82 % ± 18 % SD, n = 178) with spruce (21 % ± 14 % SD, n = 160) and mature stands (33 % ± 14 % SD, n = 160) in its macrohabitats. It avoids deciduous trees like the Grey Alder, poplar and willow (2 % ± 4 % SD, n = 160). On the other hand, the Eurasian Pygmy Owl inhabits various types of forests in distinct sub-regions of Lithuania. There was no single variable, which was more important than others for the species habitat use in three analysed sub-regions, however, different preferred/avoided variables emerged. Natural Eurasian Pygmy Owl vocalization was registered 2001 - 2011, during two seasons per year. The date of vocalization varied between years, however, the average date of owl vocalization was 20th of March in winter - spring season (n = 117) and 12th of October in autumn - winter season (n = 42). It was found, that the key factors affecting the Eurasian Pygmy Owl vocalization are atmospheric pressure at sea level (1019 hPa ± 9 hPa SD) and wind speed (1,6 m/s ±1,3 m/s SD). The owl was most vocally active 2 h 20 min - 20 min until sunrise (n = 79) and 1 h 20 min until sunset - 1 h after sunset (n = 95). |
