It is the largest North American heron, with a head-to-tail length of 36 to 55 inches, a wingspan of 66 to 79 inches, a height of 45 to 54 inches, and a weight of 4 to 8 lbs.
The primary food for Great Blue Heron is small fish, though it is also known to opportunistically feed on a wide range of shrimp, crabs, aquatic insects, rodents and other small mammals, amphibians, reptiles, and small birds. Herons locate their food by sight and usually swallow it whole. Herons have been known to choke on prey that is too large. It is generally a solitary feeder. Individuals usually forage while standing in water, but will also feed in fields or drop from the air, or from a perch, into water. As large wading birds, Great Blue Herons are able to feed in deeper waters, and thus are able to harvest from niche areas not open to most other heron species.
Great Blue Herons build a bulky stick nest, and the female lays three to six pale blue eggs. One brood is raised each year. If the nest is abandoned or destroyed, the female may lay a replacement clutch. Both parents feed the young at the nest by regurgitating food. Parent birds have been shown to consume up to four times as much food when they are feeding young chicks than when laying or incubating eggs.
Eggs are incubated for around 28 days and hatch a synchronously over a period of several days. The first chick to hatch usually becomes more experienced in food handling and aggressive interactions with siblings, and so often grows more quickly than the other chicks. Predators of eggs and nestlings include turkey vultures, several corvids, hawks, bears and raccoons. Adult herons, due to their size, have few natural predators, but can be taken by Bald Eagles, Golden Eagles and, less frequently, Great Horned Owls and Red-tailed Hawks.
We've seen these birds act very aggressively when hunting larger prey, usually they stand perfectly still while watching for their next meal. They are beautiful birds in their prehistoric awkward way.