Eared Grebe


	Eared Grebe
	Podiceps nigricollis

The most abundant grebe in the world, the Eared Grebe breeds in shallow wetlands in western North America. It occurs in greatest numbers on Mono Lake and the Great Salt Lake in fall, where it doubles its weight in preparation for a nonstop flight to its wintering grounds in the southwestern United States and Mexico.

Interesting Information

At its fall staging areas, the Eared Grebe more than doubles its weight. The pectoral (chest) muscles shrink to the point of flightlessness, the digestive organs grow significantly, and great fat deposits accumulate. Then before departure for migration, the digestive organs shrink back to about one-fourth their peak size and the heart and pectoral muscles grow quickly.
A cycle similar to that of the fall staging areas occurs three to six times each year for the Eared Grebe. For perhaps nine to ten months each year the species is flightless; this is the longest flightless period of any bird in the world capable of flight at all.
The Eared Grebe migrates only at night. Because of the length of its fall staging, its southward fall migration is the latest of any bird species in North America.
On cold, sunny mornings, the Eared Grebe, like some other grebe species, sunbathes by facing away from the sun and raising its rump, exposing dark underlying skin to light. This behavior may make the bird appear to have a distinctive "high-stern" profile.

Description

Adult Description

Size: 30-35 cm (12-14 in)
Wingspan: 52-55 cm (20-22 in)
Weight: 200-735 g (7.06-25.95 ounces)
Small waterbird.
Thin, dark bill, often appearing tilted slightly upward.
Red eyes.
In summer, black with golden ear tufts.
In winter, black, white, and gray, with white ear patch.

Sex Differences

Sexes similar.

Immature

Similar to winter adult, but more brownish on back and neck.

Breeding (Alternate) Plumage

Black head, neck, breast, and upperparts. Cinnamon flanks and white belly. Elongated yellow feathers extend back over ear area from behind eyes.

Nonbreeding (Basic) Plumage

Crown, nape, and upperparts black; sides, flanks, and front of neck grayish. Chin and throat white, with some white extending up behind dark ear areas. Head appears rounded in silhouette. Rear end rather high off water.

Photo taken from: The Sibley Field Guide by David Allen Sibley

Habitat

Breeds in shallow lakes and ponds. In migration and in winter prefers salt water. Occurs in great numbers in super salty habitats, where fish are absent.

Behavior

Feeds at surface or by diving to the bottom. Researchers believe that the Eared Grebe uses its large, fleshy tongue much as baleen whales do, crushing prey against the palate and extruding water.

Food

Aquatic invertebrates, especially brine shrimp and brine flies.

Taxonomy

Kingdom:	Animalia
Phylum:	Chordata
Subphylum:	Vertebrata
Class:	Aves
Order:	Podicipediformes
Family:	Podicipedidae
Genus:	Podiceps
Species:	Podiceps nigricollis
Subspecies:	Podiceps nigricollis californicus
	Podiceps nigricollis gurneyi
	Podiceps nigricollis nigricollis

Similar Species

Horned Grebe appears quite similar, especially in nonbreeding plumage, but shows clear border between black of crown and white of lower face rather than a more gradual transition between black and white. Front of neck is white, not gray. Rear end slopes to water instead of sticking up like that of Eared Grebe.

Bird Sound

Various trills and whirrs accompany courtship displays. Alarm call is a single sharp chirp.

Eggs look like this

Photo taken from: ARCTOS Collaborative Collection Management Solution

Bird Sound

Various trills and whirrs accompany courtship displays. Alarm call is a single sharp chirp.

	Sources Used To Construct This Page
	Cullen, S. A., J. R. Jehl, Jr, and G. L. Nuechterlein. 1999. Eared Grebe (Podiceps nigricollis). In The Birds of North America, No. 433 (A. Poole and F. Gill, eds.). The Birds of North America, Inc., Philadelphia, PA.

	All photos and videos © Rick Swartzentrover - Free for non-profit use.