Great Blue Heron

The great blue heron (Ardea herodias) is a large wading bird in the heron family Ardeidae, common near the shores of open water and in wetlands over most of North America and Central America, as well as the Caribbean and the Galápagos Islands. It is a rare vagrant to coastal Spain, the Azores, and areas of far southern Europe. An all-white population found only in the Caribbean and Florida was once treated as a separate species and known as the great white heron.

Description[]

The familiar Great Blue Heron is the largest heron in North America. It is a large bird, with a slate-gray body, chestnut and black accents, and very long legs and neck. In flight, it looks enormous, with a six-foot wingspan. Adults sport a shaggy ruff at the base of their necks. A black eyebrow extends back to black plumes emerging from the head. Juveniles have a dark crown with no plumes or ruff, and a mottled neck. In flight, a Great Blue Heron typically holds its head in toward its body with its neck bent.

Habitat[]

Adaptable and widespread, the Great Blue Heron is found in a wide variety of habitats. When feeding, it is usually seen in slow-moving or calm salt, fresh, or brackish water. Great Blue Herons inhabit sheltered, shallow bays and inlets, sloughs, marshes, wet meadows, shores of lakes, and rivers. Nesting colonies are typically found in mature forests, on islands, or near mudflats, and do best when they are free of human disturbance and have foraging areas close by.

Behavior[]

Great Blue Herons are often seen flying high overhead with slow wing-beats. When foraging, they stand silently along riverbanks, lake shores, or in wet meadows, waiting for prey to come by, which they then strike with their bills. They will also stalk prey slowly and deliberately. Although they hunt predominantly by day, they may also be active at night. They are solitary or small-group foragers, but they nest in colonies. Males typically choose shoreline areas for foraging, and females and juveniles forage in more upland areas.

Diet[]

The variable diet of Great Blue Herons allows them to exploit a variety of habitats. This adaptability also enables them to winter farther north than most herons. Fish, amphibians, reptiles, invertebrates, small mammals, and even other birds are all potential prey of the Great Blue Heron. In Washington, much of their winter hunting is on land, with voles making up a major portion of their winter diet.

Nesting[]

Great Blue Herons usually breed in colonies containing a few to several hundred pairs. Isolated pair-breeding is rare. Nest building begins in February when a male chooses a nesting territory and displays to attract a female. The nest is usually situated high up in a tree. The male gathers sticks for the female who fashions them into a platform nest lined with small twigs, bark strips, and conifer needles. Both parents incubate the 3-5 eggs for 25-29 days. Both parents regurgitate food for the young. The young can first fly at about 60 days old, although they continue to return to the nest and are fed by the adults for another few weeks. Pair bonds only last for the nesting season, and adults form new bonds each year.

Migration Status[]

In parts of their range where food is not available in the winter, Great Blue Herons are migratory, and some may migrate to Washington from points farther north. Most of Washington's breeding population remains in the state year round. In parts of eastern Washington where the water freezes, Great Blue Heron populations concentrate along major rivers where food is available, or they hunt rodents on land.