Great Blue Heron
Habitat: The most widespread heron in North America, this bird can be found anywhere near natural water, from the ocean shore to the edge of a small pond.
The white form lives almost exclusively in shallow marine waters along the coast of southern Florida, the Yucatan Peninsula, and in the Caribbean.
Intermediate forms are found in Florida where the two main Great herons overlap. These birds, with the body of a Great blue but the white head and neck of the Great white, are known as Wurdemann’s herons.
Summer Range: Breeds from southern Alaska and central Canada southward to Central America and the Caribbean.
Winter Range: Winters from southern Canada southward to northern South America, and along the coasts as far north as Alaska and Nova Scotia.
Food: The Great blue heron has an adaptable diet. Though its main food source is fish, it will also eat other animals including voles. Herons have been known to choke to death trying to swallow a fish that is too big.
Great blue herons forage in both marine coastal environments and freshwater habitats. They have two main fishing techniques. The first involves standing with the neck extended and only the head and eyes moving. When it spots prey close enough, the heron slowly folds its neck and moves one leg towards the prey. Then it unbends completely and suddenly plunges into the water catching the prey in its bill.
The second consists of the heron wading in water to drive a fish from a hiding place. When the fish is in sight, the bird slowly stretches its neck then uncoils its body and thrusts its head into the water.
Breeding Behaviour: Males and females reach the nesting ground together in the spring (late February in western Canada and late March in eastern Canada). The males choose a nesting area and either build a new nest or restore an old one. From here they work to attract a female with their calls. The birds first mate at two years of age and generally choose a new partner each year.
Nest Type and Egg Description:
Nests are usually built high in trees, swamps, forested areas, and on islands where they are safe from predators. Sometimes they are built in bushes, on ground, rock ledges, or coastal cliffs. The nesting site is most often near the feeding grounds. Sometimes the herons will nest alone, but often this is done in colonies.
Conservation Status: The Great blue heron population in North America has remained healthy, as it appears to suffer less from plume hunters and pesticides relative to other herons. The draining of wetlands and nearby urban development could threaten these birds but for the time being their numbers are stable. The exception is the coastal “Pacific” subspecies of Great blue heron, which is listed as a species “of special concern” by the Committee on the Status of Endangered Wildlife in Canada.
Information on this page compiled by Jessie Blake.
BirdLife International. http://www.birdlife.org
Committee on the Status of Endangered Wildlife in Canada. http://www.cosewic.gc.ca/eng/sct5/index_e.cfm
Cornell Lab of Ornithology. All About Birds. http://www.birds.cornell.edu/AllAboutBirds/.
Ehrlich, Paul R. 1988. The Birder’s Handbook. Simon and Schuster, New York.
Godfrey, Earl W. 1986. Birds of Canada. National Museums of Canada, Ottawa.
Hinterland Who’s Who. http://www.hww.ca
Leslie, Scott. 2006. Wetland Birds of North America. Key Porter Books, Toronto. NatureServe. InfoNatura. http://www.natureserve.org/infonatura/