Western Grebe
Aechmophorus occidentalis

Context

Kingdom: Animalia
Phylum: Chordata
Subphylum: Vertebrata
Class: Aves
Order: Podicipediformes
Family: Podicipedidae

Physical Characteristics

About 22-29 inches (55-73 cm) long, the longest of the grebes. The crown and back of neck are black, the back is brownish-gray, the underparts are white, the inner web of wing quills is white. The neck is long and slender. The female is slightly smaller than the male (Ligon, 1961). The bill is long, greenish-yellow with a dark ridge down the center (Peterson, 1990). The toes are lobed with flattened claws adapted for strong swimming and diving. There is a negligible tail (Leahy, 1982).

Habitat

Aechmophorus occidentalis is a water nesting bird (Perrins and Middleton, 1985), living in rushy lakes and sloughs. During the winter, bays and oceans are inhabited (Peterson, 1990).

Geographic Range

This species is found primarily from southeastern Alaska eastward through south-central British Columbia, central Alberta, central Saskatchewan, and southwestern Manitoba south to southern California, north-central Utah, southwestern Colorado, southwestern and northeastern New Mexico, western Nebraska, northwestern Iowa and western Minnesota. It also occurs locally in Mexico from Chihuahua and Durango south to northern Guerrero, Puebla, and San Luis Potosi. This species winters along the Pacific coast from southern British Columbia, Utah, Colorado, New Mexico, and western and southern Texas south to southern Baja California, northern Guerrero, Puebla, and San Luis Potosi(American Ornithologists' Union, 1983).

Diet

The Western Grebe is carnivorous, eating mostly insects and fish along with some mollusks and crustaceans. They spear fish with their dagger-shaped bills (Perrins and Middleton, 1985).

Reproductive Characteristics

Courtship behavior involves complex sequences of elaborate, ritualized postures. The timing of breeding is dependent upon a good food supply more than a specific time or season. There are usually 2-6 white or cream colored eggs. The incubation period is 20-30 days. The nests are mounds of aquatic vegetation, usually found in emergent weeds (Perrins and Middleton, 1985). Both parents carry their young on their backs, even while diving, in order to rest them and as a quick escape in times of danger (Ligon, 1961).

Remarks

A. occidentalis has some 20,000 feathers to keep it warm and dry. Since their feet are located far back on their body, they have a very difficult time walking; in fact, they often fall. The ankle and toe joints are very flexible, allowing them to both paddle and steer at the same time. Dives may last 10-40 seconds. Due to their wing shape, long and thin, they need a long take-off run across water to become airborne. They fly quickly with rapid wing beats, but with trailing feet. They maneuver poorly in flight (Perrins and Middleton, 1985).

American Ornithologists' Union. 1983. Check-list of North American birds, 6th ed. Allen Press, Lawrence, 877 pp.

Leahy, C. 1982. The birdwatcher's companion: an encyclopedic handbook of North American birdlife. Hill and Wang, New York, 917 pp.

Ligon, J.S. 1961. New Mexico birds and where to find them. The University of New Mexico Press, Albuquerque, 360 pp.

Perrins, C.M. and A.L.A. Middleton, ed. 1985. The encyclopedia of birds. Equinox, Ltd., Oxford, 447 pp.

Peterson, R.T. 1990. A field guide to western birds. Houghton Mifflin Company, Boston, 432 pp.

Mary Kirschenbaum, July 1996.