The American crow is omnivorous. It will feed on invertebrates of all types, carrion, scraps of human food, seeds, eggs and nestlings, stranded fish on the shore and various grains. American crows are active hunters and will prey on mice, frogs, and other small animals. In winter and autumn, the diet of American crows is more dependent on nuts and acorns. Occasionally, they will visit bird feeders. The American crow is one of only a few species of bird that has been observed modifying and using tools to obtain food.
This bird is a permanent resident in much of its range. Northern birds migrate in flocks to the Southeastern United States. The distribution of the common grackle is largely explained by annual mean temperature, and the species has expanded its range by greater than three-fold since the last glacial maximum, approximately 22,000 years ago.