Some populations migrate to the S. America during the winter months. The great blue heron fishes in both night and day, with most of its activity around dawn and dusk. The great blue heron's diet consists of fish, frogs, salamanders, lizards, snakes, shrimps, crabs, crayfish, dragonflies, grasshoppers, and many aquatic insects. The great blue heron typically breeds during the months of March - May in its northern range and November through April in the southern hemisphere. The nest usually consists of an egg clutch between 3-7 eggs, with clutch size increasing from south to north.
Chicks fledge at about two months.
The great blue heron is relatively quiet compared to othermembers of its family. The great blue heron's habitats include rivers, lake edges, marshes, saltwater shores, and swamps. The bird usually nests in trees near water. This is the most well-known and most widespread heron in North America. Human interference with the heron primarily involves destruction of habitat.