Saker falcons are active during the day when they spend most of their time hunting. They often hunt by horizontal pursuit and usually close to the ground. They are very patient hunters soaring in the air or sitting on the perch for hours watching for prey; once the prey is spotted they dive in suddenly for the kill. Saker falcons are carnivores and feed mainly on rodents and birds. In Europe, their most common prey is ground squirrels and feral pigeons. Saker falcons have sharp curved talons to grasp the prey and they use their powerful hooked beak to sever the vertebral column of their victim.
Saker falcons are not very social birds; breeding pairs prefer to nest alone, however, in areas where food is plentiful, birds may then nest closer to each other. Sakers occupy old stick nests in trees, about 15 to 20 meters above the ground. They use nests which were previously used by other birds such as storks, ravens or buzzards and sometimes even drive away owners from an occupied nest. In the more rugged areas of their range, sakers have been known to use nests on cliff ledges.