Ardea herodias
(Great Blue Heron)

Order: Ciconiiformes
Order Description: Bitterns, Herons, Egrets,and Ibises
Family: Ardeidae
Family Description: Herons, Bitterns, and Egrets

Physical Description:
Size: 42-52" (107-132 cm). A lean, tall gray-blue bird. Back and wings are blue-gray, underparts whitish. Head white with a black stripe ending in black plumesClick word for definition behind the eye. Black and white foreneck and chest end in gray plumes in the breeding adults. Bill thick, yellow, daggerlike. Thighs rufousClick word for definition. It flies with its neck coiled.

Similar Species- Sandhill Crane has a red cap, is heavier, shorter billed and flies with its neck and legs outstretched.

Generally silent, makes a loud Croak sound when startled or alarmed.

Breeds from southeastern Alaska and southern Canada, south to southern Mexico. Winters from southeastern Alaska, central U.S., and southern New England, south to northern South America. Wanders widely outside usual range. Some sub-adults may summer in non-breeding range.

Found on freshwater and brackishClick word for definition marshes, along lakes, rivers, bays, lagoons, ocean beaches, fields, and meadows. In Idaho, species follows major watercourses.

Eats fishes, insects, crustaceans, amphibians, reptiles, mice, shrews, and other animals.

Builds nest in tree, sometimes in shrub, rarely on ground. Nests in colonies. Colony size can vary from few pairs to hundreds of pairs; colonies may be displaced by Bald Eagles. In general, individuals are most active just before dawn and at dusk, but Idaho study found herons come and go from colonies regularly, with no peak activity periods. Individuals usually forage while standing in water, but will also forage in fields or drop from air (or perch) into water. May establish feeding territories in winter. Usually solitary when not breeding. In Idaho, some herons are year-round residents while others, especially in northern Idaho, are breeders or transients. Species is most common and widely distributed colonial waterbird in Idaho.

Both sexes incubateClick word for definition 3- 7 eggs (usually 4), for 25-29 days (Idaho study reported mean colony size at 24.6 birds with 2.2 young/nest). Both parents tend young, which leave nest in 60-90 days, and may first breed at 2 yr.

Element Code: ABNGA04010
Status: Protected nongame species
Global Rank: G5
State Rank: S5
National Rank: N5B,N5N

Important State References:
Trost, C.H. 1994. The status and distribution of colonial waterbirds in northern Idaho and selected species in southern Idaho, 1994. Dept. Biol. Sciences, Idaho St. Univ., Pocatello. 31pp.

Photos by Ed Dijak,© 2000
Design by Ean Harker©1999, 2000.
Written by Jason Karl, 2000.