Bird of the Month: Double-crested Cormorant

Creative Commons 2.0, by Ken and Nyetta, via Flickr.Com.

By Russ Chappell

Double-crested Cormorants are large, expert fishermen with a diet of fish supplemented with insects, crustaceans, and amphibians. They pursue underwater prey with powerful kicks of their webbed feet, and if they catch a crustacean, they strike it on the water until the legs break off, then flip it in the air, and catch it head first for easier swallowing.

They have goose like bodies, long, loon-type necks, and thin, strongly curved bills, approximately the length of their heads. Adults are brown-black with yellow-orange facial skin, and the immature birds are browner with paler necks and breasts. They have aquamarine-colored eyes and bright blue inside their mouths. During breeding season, adults display double-crests of white or black scruffy feathers on their heads, thus the Double-crested Cormorant name.

When not fishing, they rest on branches, rocks or the shore with their wings spread to dry, since their feathers contain less preen oil than other water fowl. This is a minor inconvenience that contributes to their underwater speed and maneuverability.

Double-crested Cormorants usually reside near large bodies of water, however many form breeding colonies near small ponds and travel up to 40 miles to a quality feeding site.

Listed as “uncommon transient and casual summer and winter visitors” in Professor Carl Tomoff’s “Birds of Prescott, Arizona,” they raise two broods a year with up to seven chicks per brood.

A male attracts a mate by locating a nesting site where he stands, breast down, bill and tail up, showing off his double crests and brightly colored neck and eyes. He grunts and waves his outstretched wings then greets his mate with an open mouth displaying its bright blue color.

Both mates contribute to nest building, the male collecting materials and the female doing the construction. A nest is made of small sticks and flotsam, and lined with grass, 18 to 36 inches in diameter and 4 to 17 inches deep. (Ground nests may be wider and tree nests deeper.)

The oldest known Double-crested Cormorant was at least 22-years-and-six-month-old and the species is classified as “Least Concern.”

Adding this species to your “big list” may be as easy as visiting an area lake, where you may witness these expert fishermen at work. Happy birding.

*****

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The Prescott Audubon Society is an official chapter of the National Audubon Society. Check them out online at PrescottAudubon.Org.

Russ is a member of the Prescott Audubon Society and enjoys photographing and studying the large number of species in our region, and learning to be a better steward of our beautiful natural resources.

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