ИСТИНА

The research was carried out in the north of Moscow Region (Russia) in 2001–2014. The dependence of the population dynamics of both species on the environment parameters was analysed using generalized linear models (GLM). There were four peaks in population dynamics of predators and voles. Years with high number of voles coincided with an increase of breeding number of Short-eared Owls within the study area. Results of modeling showed that the trophic and meteorological parameters significantly affected the number of Long-eared Owls. Highest number of Long-eared Owls was related to the vole abundance (β±SE=0.23±0.03). Weather factors affected the number twice weaker (β=0.12±0.02). Long-eared Owls number was found to be positively related to average temperature of spring months and negatively - to the snow depth in March-April and precipitation in spring. Both parameters were significantly correlated with the number of Short-eared Owls. Factor associated with meteorological parameters affected owls weaker than the trophic factor: β = 0.05 ± 0.02 and β = 0.24 ± 0.0, respectively. Thereby, the population dynamics of owls simultaneously affected by the abundance of prey and various meteorological factors. Meteorological factors influenced the population dynamics of Long-eared Owls much stronger than of Short-eared Owls.