Budget comparison of Common Buzzard Buteo buteo and Rough-legged Buzzard Buteo lagopus on the wintering grounds (#834)
Behavioural observations of two sympatrically wintering buzzards were made in the Liwiec River valley in eastern Poland. Percentage of time spent on particular type of flight differed between both species. Soaring and hovering were more often used kind of air activity by Rough-legged Buzzard, while Common Buzzard more frequently used flapping flight. Perching was the main form of hunting in both buzzard species. However, Rough-legged Buzzard more often sit on the ground and rarely used fence post in comparison to Common Buzzard. Regression models showed that weather conditions affected the activities of both species in different way. Snow depth negatively correlated with time spent on the ground and positively with time of perching on a tree in Common Buzzard. Wind speed positively affected the time spent on flapping and hovering and negatively the perching time on a tree in Rough-legged Buzzard. These results support the hypothesis that different techniques of exploitation of the same food resources are connected with reduced interspecific competition.