Hunting methods and success rates of Gyrfalcons, Falco rusticolus, and Prairie Falcons, Falco mexicanus, preying on feral pigeons (Rock Doves), Columba livia, in Edmonton, Alberta

Abstract

Three adult female Gyrfalcons (Falco rusticolus) and one adult female Prairie Falcon (Falco mexicanus), wintering in Edmonton, Alberta, killed 15 and 27 feral pigeons (Rock Doves, Columba livia) respectively in 141 and 104 hunts. The Prairie Falcon's hunting success rate (26.0%) was significantly greater than that of the Gyrfalcons (10.6%). Six kills (40%) by Gyrfalcons and 18 kills (67%) by the Prairie Falcon were the result of surprise attacks on sitting pigeons. Open attacks on flying pigeons resulted in nine captures each. Gyrfalcons typically attacked airborne flocks of pigeons with upward swoops from below, whereas the Prairie Falcon stooped down at them from above. Both species often resumed hunting immediately or soon after consuming a pigeon. On one occasion, the Prairie Falcon killed four pigeons of which three were abandoned in 20 minutes. Besides capturing live prey, a Gyrfalcon stole a pigeon from the Prairie Falcon, and another Gyrfalcon scavenged four dead pigeons.