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Characteristics of the Great Blue Heron

The great blue heron is the largest of the American herons and can be found in both freshwater and saltwater, in marshes, swamps, and in still or slow flowing water. It's a wading bird that breeds in much of North and Central America. The northern populations migrate south for the winter, some flying as far south as Venezuela. A great blue heron may live as long as 23 years, but most live no longer than 15 years in the wild.

Body
- The great blue heron stands about 2 feet tall and about 50 inches long and weighs from 4.6 to 5.5 lbs. They are blue gray on the back with long white or gray plumes on their backs and wing scapulars. They also have a black shoulder patch and a patch on the top of their head. There's also a ring of white or gray plumes around the neck. Their eyes are yellow. Males are a bit bigger than females, but otherwise the sexes are alike. Juveniles have darker feathers and lack the plume feathers.
Reproduction
- Great blue herons breed from March to May in the northern part of their range and in November through April in the southern part. Males arrive at the breeding ground first and choose an existing nest, though young males might build a new one. The nest is a shallow platform made of sticks and branches. It's built in trees, bushes or even at ground level in a marsh, though herons prefer to nest at greater heights. Some nests are as high as 69 feet off the ground. Great blue herons like to nest in colonies.
Rearing Young
- Great blue herons are monogamous, and the male will court the female while in his nest by stretching his neck and puffing out his plume of neck fathers. He may fly in a circle around the nest or shake twigs. If the female's interested in him, it perches next to the male, and they'll both display their crest feathers and clack their beaks together. After mating, the female lays between two and seven pale blue eggs which both parents incubate. The chicks are born with down and with their eyes open, but they can't feed themselves. Their parents feed them regurgitated fish.
Diet
- Great blue herons take fish most of the time, and they hunt mostly around dawn and dusk. They use their spear like bills to catch their food, and they may wade up to their bellies to do so. They also take small reptiles, amphibians and crustaceans. Occasionally they will hunt on dry land and stalk prey in open habitats. Mice, gophers and other small mammals are also taken. The prey is usually swallowed whole.

Animals & Science