Intraguild Predation by Eurasian Eagle-Owl Bubo bubo on Booted Eagle Aquila pennata and Long-Legged Buzzard Buteo rufinus

Abstract. In August 2018 remains of several birds of prey were recorded at one Eagle Owl Bubo bubo eyrie in southeast Romania. Among these, still articulated wings and leg bones of an adult female Booted Eagle Aquila pennata, feathers and several bone fragments of one adult Long-legged Buzzard Buteo rufinus and several individuals of Common Buzzards Buteo buteo were identified. While predation of Eagle Owls on different raptor species is well known, booted Eagles and Long-legged Buzzards are rarely preyed upon. Based on changes that occurred in the overall diet of owls at this particular eyrie, it is hypothesized that a shortage in the main prey species (induced by land use changes in the region) may be the cause of these extraordinary predation events. While predation of Eagle Owls on large diurnal raptors is more an exception than a norm, in areas where threatened diurnal raptors breed, the presence of Eagle Owls may cause conservation concerns/prove to be problematic.