Footedness bias in hunting birds of prey

Birds of prey use their feet to capture prey, particularly when occurring on the ground, and thus they are good candidates for studies on footedness, i.e. the preferential use of limbs. This preference is still poorly known among birds in general. Several successful attempts of predation by rehabilitated Falconiformes and Strigiformes were analysed. Those birds' predatory ability is routinely tested to evaluate the success of their release to the wild. One laboratory mouse was usually offered, but other species, ranging from grasshopper to one-day-old chick or small rat, were used as well. Kestrels Falco tinnunculus and Common Buzzards Buteo buteo tended to grip with only one foot, but without side preference. The foot used in the first test was also used subsequently. In contrast, owl species such as the Barn Owl Tyto alba and Tawny Owl Strix aluco used mainly both feet. Young Barn Owls were more variable than adults in foot use. In contrast, the Little Owl Athene noctua, a rather diurnal owl, showed strong preference for using the right foot only. Birds of prey then show various degrees of footedness, with limited difference between individuals, and such species differences are likely related to environmental constraints.