| Abstract [eng] |
Environmental changes, which are mainly related to human impact on natural habitats and climate change, mostly affect sedentary, high trophic level species, however, little is known about the response of these species to the changes. The aim of this study - to determine the dynamics of individual body size, body condition, colour morph, start of breeding, reproduction and survival success, as well as relationships and links with habitats and climate change, for a sedentary species of raptor bird Tawny Owl (Strix aluco). This study analyses data collected between 1978 and 2014, on 186 owl breeding events, 61 captured and marked owl females, autumn-spring climate conditions and habitats within 0.4 km radius around the nest boxes. Regression analysis showed that the number of nesting owl pairs, breeding success and nesting individuals’ size varied during the research years. In addition, the early start of breeding trend and the breeding frequency upward trend were observed. Better body condition females bred earlier and achieved higher reproductive rates. Tawny owls chose habitats with greater forest opening, mature forest and extensive field areas, and avoided young forests. Breeding success was significantly related with the occupied habitat, indicating owl habitat selection adaptivity. Owl breeding start was linked to autumn and winter weather conditions, in addition, autumn precipitation affected the body condition of owls during breeding season. Although different colour morph owls did not differ in body size and body condition, the intermediate morph individuals bred more often and raised more offspring indicating better fitness of intermediate individuals under local environmental conditions. |
