Patterns of territory size and defence level in rural and urban tawny owl (Strix aluco) populations

摘要: The effect of different variables on the territory size and defence level tawny owl (Strix aluco L.) populations was studied in two habitats: mixed farmland (1976–1978) town (1986–1988). Territory determined by plotting position territorial challenges (hoots) males which were individually recognizable most cases. No differences found size, defence, number competitors biomass between territories town, but more fragmented showed a larger nearest neighbour distance. Size rural adequately predicted both some structural habitat features food supplies, while urban affected only structure years occupancy. competing neighbours either habitat, thus confirming that behavioural interactions owners potential settlers prevent decrease size. Defence 'social’variables (nearest distance occupancy), (percentage poplar grove diversity), supply, (fragmentation or natural vegetation) supplies level. This due to settlement tactics areas, depending extent quality suitable habitat.