BREEDING BIRDS: GREAT BLUE HERON

GREAT BLUE HERON

(Ardea herodias)

Description: Large, gray-blue heron. Black stripe extends above eye; white foreneck is streaked with black. Breeding adult has yellowish bill and ornate plumes on head, neck and back.

Habitat: Freshwater and brackish marshes, swamps, lakes, rivers.

Diet: Mostly fish, but sometimes also feeds on human food scraps, nestlings, small mammals.

Displays: Pairs will rest their crests and clap bills.

Nest: Builds a platform nest in a tree or on a cliff. The large, flat nest is made of interwoven sticks and lined with twigs and leaves.

Eggs: Light bluish-green, about 2 1/2 inches long.

Natural history notes: Nests in eucalyptus trees at isolated small rookeries in Orange County; large rookeries are located in Morro Bay, Goleta, Point Lomas, Salton Sea and elsewhere. When the herons were done nesting last season at one site near the Santa Ana River Lakes fishing area in Anaheim, the vacated nests were taken over by later-breeding double-crested cormorants, the first time nesting cormorants have been recorded in the county.

Note: Map is divided into 5-kilometer squares so that Audubon Society volunteers can more easily survey areas on a regular basis.

Sources: Sea and Sage Audubon Society Breeding Bird Atlas; “The Birder’s Handbook,” Ehrlich, Dobkin and Wheye, Fireside Books (1988); “Field Guide to the Birds of North America,” National Geographic Society (1987); “Birds of Southern California: Status and Distribution,” Garrett and Dunn, Los Angeles Audubon Society (1981).

Indicates 5-kilometer-square areas where breeding activity has been confirmed.