Incubation takes 28 days. Young are able to fly after 56-60 days. Both sexes tend young. Mostly fish, but opportunistic, including human food scraps, nestlings, small mammals. Young fed fish.
Winters s to n South America.
Average clutch size increases with latitude to 5 in s Canada. Marshes, lakes, swamps, rivers, lagoons, coasts, mangroves. Populations in the Caribbean are polymorphic and the white morph was formerly treated as a separate species, A. occidentalis, the Great White Heron, now usually considered a race of herodias, as below. A. h. herodias. Is., rarely to Hawaiian Islands.