SIMoN
  Sanctuary Integrated Monitoring Network
SIMoN Tools

Species Database

Podiceps nigricollis - Eared Grebe

Eared Grebe image

Geographic range:

Worldwide

Key features:

Small, thin-necked, red-eyed, dark grey body with a short, pointed yellow bill. Rear is square with no elongate tail feathers.

Similar species:

Podilymbus podiceps -- Pied-billed grebe
Podiceps grisegena -- Red-necked grebe
Podiceps auritus -- Horned grebe

Habitat(s):

bay (rocky shore), bay (sandy shore), estuary
 

Primary common name:

Eared Grebe

General grouping:

Seabirds and shorebirds

ITIS code:

174485
 

Geographic Range

Range Description:

The Eared Grebe is the most abundant grebe in North America and the world. The subspecies, Podiceps nigricollis nigricollis breeds in the British Isles, Scandinavia, West Siberia, Morocco, Iraq, Afghanistan, Manchuria, east Africa in the Rift Valley from Ethiopia to Tanzania, Asia, India and Pakistan. In the winter it is found in the British Isles south to the Mediterranean Sea, the Nile valley, sw. Asia, northern India, and the Ryukyu and Bonin Islands. The Black Sea, the Caspian Sea, Turkish lakes and the Persian Gulf are major wintering areas. Another subspecies, Podiceps nigricollis gurneyi, is found in South Africa from Transvaal to Cape Province, and occasionally north to Angola and Mozambique. The North American Eared Grebe breeds widely through the interior of the western United States and Canada. It prefers shallow alkaline lakes and ponds, feeding primarily on invertebrates. In the Monterey Bay area Eared Grebes are common and resident in the winter (September-April) along the coast, in bays and estuaries (e.g., a few at Elkhorn Slough and the Salinas River mouth), and on large inland lakes, such as Lake San Antonio. Migrating Eared Grebes may be sighted during March-May. In North America the Eared Grebe is usually absent from higher elevations of the Rocky Mountains. In the United States it breeds from the Canadian border south through Montana and east to North Dakota, Minnesota, Iowa, Nebraska, and south and west to Colorado, New Mexico, Arizona, Nevada, Idaho, Washington, Oregon and north and central California. The greatest numbers occur on Mono Lake and the Great Salt Lake in the fall, where they double their weight in preparation for a nonstop flight to wintering grounds in the southwestern United States and northern Mexico.

Habitats

bay (rocky shore), bay (sandy shore), estuary

Habitat notes:

Most likely seen in Elkhorn Slough.

Abundance

Relative abundance:

Common.

Species Description

General description:

The Eared Grebe is a small, stocky grebe, with dark gray to black upperparts, dark chestnut-brown flanks and white underparts. It has a thin, approximately one inch long yellow bill with a very slightly upturned tip. The head and thin neck are dark gray to black, with golden, orange feathers radiating behind the red eyes, flaring out to the rear during breeding season. During breeding season the body is all dark with cinnamon-brown underparts, while in winter the plumage is duller with gray neck, whitish belly, and white chin, extending to whitish ear patches. The head has a triangular appearance, with a peak towards the center of the head. The eyes are red, the legs and lobed feet are black. The legs are set far back on the body and trail behind the body in flight. Its flight is direct with rapid wing beats, with white secondaries visible in flight. However, for 9-10 months of the year it is flightless, the longest flightless period of any bird that is able to fly. It generally rides high on the water exposing fluffy white undertail coverts. On cold but sunny mornings, it sunbathes, facing away from the sun and raising its rump, exposing the dark underlying skin to the warmth and light from the sun, and giving it a distinctive \"high-stern\" profile.

The call of the Eared Grebe varies: in courtship it has a soft, frog-like poo-eek-chk; on the breeding grounds a squeaky, whistled oo-EEK; and an alarm call of just a single sharp chirp. They are gregarious, nesting in large, dense colonies, sometimes numbering in the thousands. They also assemble into large flocks in winter. A group of grebes are collectively known as a \"water dance\" of grebes.

Distinctive features:

The Eared Grebe has a small body, thin-neck, red-eyes, and dark grey with reddish flanks. A short pointed yellow bill and golden, orange feathers radiating behind the eyes and flaring out to the rear during breeding season. Basic coloration is gray head, face, hindneck and back, with white chin, whitish flanks and belly, and dusky fore-neck.

Size:

Length: 12.5 to 13 in (32 – 33.5 cm)
Wingspan: 16 in (40 cm)
Weight: 11 oz (300 g)

Natural History

General natural history:

Eared Grebes are the most abundant grebe in the world and are gregarious, nesting in large, dense colonies, sometimes numbering in the thousands. The Eared Grebe belongs to the group of diving birds (Order Podicipedes), which also includes loons and auks. They are more closely related to loons, but differ from loons in having the head incompletely feathered near the nostrils and having feet that are not completely webbed, but having lobed toes like a coot. The wings are inadequately developed for protracted flight (but good for propulsion through the water) and on land locomotion is difficult because their short legs are located relatively far back on the body. They must take off and land in water. However they are expert swimmers and divers, swimming below the surface to find food. Their nickname “Hell-diver” refers to the speed with which they dive. When alarmed they sink quietly into the water by compressing their thick plumage along with internal air reservoirs. Only their bill remains above the surface of the water. Having dense bones, a reduced tail, and flattened lower leg bones (reducing drag) helps them achieve this sinking behavior. They sink easily, enabling them to escape predators and also to capture prey.

The Eared Grebe has a large geographic range, estimated globally at 1,000,000 to 10,000,000 square kilometers. It is native to many of the nations of Europe, Asia, and North America and prefers wetlands and marine ecosystems, though it has been known to reside in ponds, water storage areas and wastewater treatment areas. The global population of this bird is estimated between 3.9 and 4.3 million individuals and is not on the IUCN Red List.

Predator(s):

Few predators. There are anecdotal reports of Great Blue Heron and Western Gulls taking adults. Occasional predation of eggs and chicks has been reported.

Prey:

Feeds on aquatic insects, larvae, fish, mollusks, amphibians, amphipods, crustaceans (especially brine shrimp), and feathers.

Feeding behavior

Carnivore

Feeding behavior notes:

Forages by: diving, often in unison when in a flock; sinking, for submerged prey; head skimming, for surface prey; dipping, before diving to make observations; pecking, for items on rocks or vegetation; plucking, for airborne insects; and swimming underwater propelled by feet.

July - October

Migration:

Winter Migration, first stage
Adults leave their breeding ground first, followed by the juveniles a month later. They undergo a molt migration to hypersaline lakes (salinity >50%) in the Great Basin of the western U.S. They migrate only at night, in large flocks. Routes are overland to principally the Great Salt Lake, UT and Mono Lake, CA.

October - November

Feeding:

After molting they stay in the Great Basin lakes, more than doubling their weight. Their chest (pectoral) muscles shrink until they are unable to fly, but their digestive organs grow and they accumulate large fat deposits. Then, in order to continue to their wintering grounds in southern U.S. and Mexico, they need to fast to shrink the digestive organs, and exercise their wings to stimulate the flight muscles and heart to grow. As the prey items disappear with the arrival of cooler weather, the fast is inevitable.

December - January

Migration:

Winter Migration, second stage
Departure from the Great Basin lakes to the south for the winter occurs around December and January. The immature Eared Grebes leave earlier than adults. The main migration is nocturnal and the route is southward across southern U.S. deserts to the Gulf of California. Others move southeast toward mainland Mexico, others southwest to the California coast between Santa Barbara and San Diego. They assemble in large flocks. Small numbers winter at other more northerly coastal and inland sites in western North America.

January - April

Migration:

The northward nocturnal migration begins late in January, continuing into April, peaking in March. The grebes move northward, often staging at the Salton Sea, CA for several weeks, where thousands have been seen on a single day. Smaller numbers move north along the Pacific Coast. They reach their nesting areas in the northern United States and Canada by late April and May.

May - August

Reproduction:

Courtship on the water precedes nest building and is complex. It includes a “penguin dance”, with partners facing each other while rearing up out of the water, turning heads from side to side. They may then rush across the surface of the water side by side. One of the pair may crouch on the water in a cat-like position while the partner swims submerged toward its mate. Before nest building the pair copulate on floating vegetation. They defend against and fight off soliciting birds. The pair remains monogamous during the season. Nest building usually begins in May on the breeding grounds in northern U.S. and Canada. Nesting in dense colonies (over a thousand birds), in marshes away from trees, both parents build a well-concealed floating platform of weeds, anchored to vegetation in shallow water of large freshwater lakes and reservoirs, which ideally provides free swimming for escape. The whole nest is wet and the center may be below water level even when the adult is not on it. The lower half of each egg is always wet. Three to five elliptical, 1.7 inches long (43 mm), bluish-white, chalky, eggs are laid at an interval of one egg per day. They soon become nest-stained and brown. They are incubated by both parents for about 21 days. Males are larger than females and incubate longer than females. The eggs are attended 99% of the time.

The first hatched chicks are brooded on the back of an incubating parent and fed by the other parent. This back brooding/feeding arrangement continues after all the chicks are hatched and as soon as all have hatched the new family leaves the nest. Both parents feed and tend the young. A parent captures prey, then swims rapidly to the back-riding chick who takes the prey from the parent’s bill. They are also fed feathers by the parents. Ingested feathers contribute substance to the stomach contents and enable pellet formation of bone fragments and other indigestible parts.

In less than a week the parents take turns back brooding and by about day 10 the parents often split up, each parent taking half of the brood. Many broods hatch with 3 to 5 chicks but eventually are reduced to two chicks in most cases, with each chick attended by one parent. The young are usually independent in about 21 days. Parents usually leave the breeding wetlands before their young can fly. After 3 weeks the chicks are able to feed as an adult does, including bottom probing and will join the adult flock in a month or so.

Listing Status:

The global population of the Eared Grebe is estimated to be 3,900,000 to 4,300,000 individuals and it does not appear to meet population decline criteria that would necessitate inclusion on the IUCN Red List. The current evaluation status of the Eared Grebe is Least Concern.

However because such a high percentage of Eared Grebes rely on so few lakes and because colony locations change frequently, protection of all wetlands that offer a suitable habitat is important. Loss of habitat from wetland drainage, drought, conversion to agriculture, use of water for irrigation, and maintaining high water levels to support recreational fishing are all problematic.
Click on an image below to view a larger version in the SIMoN Photo Library. You will also be able to view important information on each photo such as photographer, date, caption and more.
Ehrlich, P., D.S. Dobkin, and D. Wheye. 1988. The Birders Handbook: A Field Guide to the Natural History of North American Birds. Simon & Schuster Inc., New York. 785 p.
NOAA. 1994. Beached marine birds and mammals of the North American West Coast: a revised guide to their identification. NOAA Sanctuaries and Reserves Division, U.S. Department of Commerce
Peralta-Gallegos, J.C, A. Castellanos-Vera, and A. Ortega-Rubio. 2004. Predation by the Western Gull on the Eared Grebe at a Salina in Mexico. Waterbirds 27(4):483-485.
Peterson, R.T. 2010. Peterson Field Guide to Birds of Western North America, Fourth Edition. Houghton Mifflin Harcourt. 512 p.
Roberson, D. 2002. Monterey Birds 2nd edition. Monterey Peninsula Audubon Society, Carmel, CA. 536 p.
Sibley, D.A. 2000. The Sibley Guide to Bird. Alfred A. Knopf, Inc. 545 p.
WWW
Alaska SeaLife Center
http://www.alaskasealife.org

WWW
Birds of North America Online
http://bna.birds.cornell.edu/bna

WWW
Cornell Lab of Ornithology
All About Birds
http://www.allaboutbirds.org/guide/search

WWW
Nutty Birdwatcher
http://www.birdnature.com

WWW
WhatBird.com. Field Guide to Birds of North America.
http://www.whatbird.com