Probst R., Nemeschkal H.L., McGrady M., Tucakov M. & Szép T. (2011) Aerial hunting techniques and predation success of Hobbies Falco subbuteo on Sand Martin Riparia riparia at breeding colonies. ARDEA 99 (1): 9-16

We analysed 291 attacks by 15 male Hobbies Falco subbuteo at 13 different Sand Martin Riparia riparia colonies in Austria, Hungary, and Serbia in 2004 and 2005. We predicted that the choice of escape strategy would be context-dependent and related to the condition and age of swallows and relative position and flight characteristics of both predator and prey. We predicted that swallows would be unable to escape falcons in a level chase and would not seek cover. We predicted that falcons would be more successful when juveniles were present. Hunting success rates were higher during the swallows’ post-fledging period, probably because of the weaker flight performance of juveniles. Invariably, adult swallows tried to outclimb falcons, while probable juveniles also tried to escape to cover. Hobbies most often attacked adult swallows by a fast approach from great heights and distances. In contrast, in the post-fledging period, when juveniles were available, low horizontal attacks and long climbing chases were common. In doing so, Hobbies at times prevented juvenile swallows from taking cover and were, in turn, sometimes able to outclimb and capture them. Significantly more attacks were abandoned during the post-fledging period. Sand Martins were unable to escape Hobbies in a level chase. Individual male Hobbies showed no difference in hunting success, maybe because all were experienced. The number of Sand Martins present at the time of attack did not influence hunting success. The results are discussed in the light of the anti-predator strategies of animals living in groups.