Flocks of crows range widely for food, up to 30 miles a day in winter. Crows have extremely keen senses of sight and hearing. They are wary and usually post sentries while they feed. Sentry birds watch for danger, ready to alert the feeding birds with a sharp alarm caw . These skillful fliers have a large repertoire of moves designed to throw off airborne predators.
Crows are relatively gregarious.
Throughout most of the year, they flock in groups ranging from family units to several hundred birds. During winter, crows may gather by the tens of thousands in areas where food is plentiful. Later, these flocks break up as mate selection takes place. Males vie for mates through fighting and spectacular flight routines. Once paired, male and female search out a secluded woodlot to raise their brood.