Great Blue Heron

Ardea herodias



For inquiries contact Steve Johnson, Graduate Student, Organismal and Evolutionary Biology, University of Massachusetts Amherst

Standing motionlessly in still shallow water along the edge of the Connecticut River is the patient Great Blue Heron. By silently waiting in the shallows, the heron is rewarded with the approach of fish, amphibians, and crayfish, which are quickly caught by the spear-like bill.

On land, the heron also eats small mammals, and even birds. The Great Blue Heron uses a wide variety of strategies for hunting food, partially because this heron is found in a wider range of habitats across more of North America than any other heron. Herons also wade or stalk prey in saltwater marshes, beaches and uplands.

Close to four feet tall, the Great Blue Heron is the largest heron in North America. Almost all parts of this heron can be described as long. The long wings and back are blue gray. The long bill is yellow. The long neck is mostly gray, with black flecks running down the front of the neck. The long legs are brown, or sometimes greenish. About the only thing not long on a Great Blue Heron is its tail, which is decidedly short, and black. A black "eye brow" runs above each eye, and in breeding plumage extends out behind the head.

While bedecked in bright breeding plumage, Great Blue Herons perform elaborate courtship displays involving extended necks, bill raising and snapping, moaning goo-goo calls, preening, circular flights, twig shaking and transfers, crest raising, bill duels and more. All this courtship forms a strong pair bond, which the newly paired birds will need to raise their young.

The Great Blue Heron nests in large colonies with hundreds of mated pairs. These colonies are usually in forested wetlands or on islands with trees. The herons build large nests of twigs high in the trees to discourage predators, such as raccoons and snakes. The nests are often 3 feet across and almost as tall. The colonies are easily recognized by the hundreds of nests scattered throughout the trees.

The parents take turns keeping the eggs warm until hatching, then share in feeding the young herons. The adult herons place food into the open mouths of the young for the first three weeks, by then the young will actually pull the parent's bill into the nest, sometimes even reaching into the adult's open mouth for food. In 7 to 8 weeks, the young will fledge, flying from the nest for the first time.

Because Great Blue Herons have a six-foot wing span, they are unforgettable if seen flying overhead. Sometimes when a heron is startled, it will fly off slowly beating its wings and giving a harsh and very loud croak or call described as "FRAWNK". To many bird watchers, this feels a great deal like watching a flying dinosaur soar past.

Many Great Blue Herons migrate south for the winter, but in New England, some stay around if there is open water, and many others head east and over winter along the coast instead. Because these herons stay so close through the winter, they are among the first birds to return in the spring.