Behaviour of wild rehabilitated buzzards after release

This study describes the behaviour of a sample of 16 rehabilitated buzzards (_Buteo buteo_) during the first 3 days after release in a farming area of the flatland created by the Po River, a few kilometres from the river itself. The birds were released in the study area individually and in different seasons. The activity of the buzzards was recorded continuously for at least the first three days after release and intermittently afterwards until dispersal from the release site. They were located with radio-tracking devices and observed continuously with binoculars during the day. The birds remained in the surroundings for even more than 100 days, showing a progressive acclimatisation to the new environment. The distance from the release site increased progressively to 1295.0 ± 217.4 m on day 3, suggesting an improvement of the strength and endurance of the pectoral muscles, not fully acquired in captivity during the pre-release flights. Moreover, flight length was positively correlated with both distance from the release site (rs = 0.133, n = 692, P < 0.001) and flight height (rs = 0.314, n = 219, P < 0.001). The predatory behaviour was almost normal, although certainly underestimated. Ninety-two predation attempts were observed, whose different techniques were related to the habitat and the season. The buzzards caught most often small mammals, reptiles, and insects (71.5%) but never attempted to capture any bird. Released buzzards interacted frequently with wild territorial conspecifics; however, such interactions were not the direct cause of dispersal. Some birds defended a territory adjacent to or inside that of a wild buzzard. Many buzzards interacted with other species, mainly Corvids, that mobbed frequently, especially the hooded crow (_Corvus corone_). Although the area chosen for this study had a high level of human population, this was not a major source of interference. Thus, the buzzards appeared to be able to cope with their new environment being minimally influenced by the captivity period.