Species: Podiceps nigricollis

Eared Grebe

Species

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Encyclopedia of Puget Sound

See Kaufman (1992, Am. Birds 46:1187-1190) for detailed information on identification of birds in basic plumage. Eggs: in Oregon, mean length was 44.6 mm, mean width was 30.2 mm, and mean mass was 22.8 g (Hill et al. 1995, Condor 97:1062-1064).

Classification

Kingdom

Animalia

Phylum

Craniata

Class

Aves

Order

Podicipediformes

Family

Podicipedidae

Genus

Podiceps

NatureServe

Source:
ELEMENT_GLOBAL.2.100013

Classification

Other Global Common Names

Black-necked Grebe - Zambullidor Orejudo - grèbe à cou noir

Informal Taxonomy

Animals, Vertebrates - Birds - Other Birds

Formal Taxonomy

Animalia - Craniata - Aves - Podicipediformes - Podicipedidae - Podiceps - Potentially constitutes a superspecies with P. ANDINUS and P. OCCIPITALIS (AOU 1998). P. ANDINUS of Colombia sometimes considered a race of NIGRICOLLIS (AOU 1998). P. CASPICUS, used by some authors for P. NIGRICOLLIS, has been officially suppressed (AOU 1983, Banks and Browning 1995).

Ecology and Life History

Migration

false - false - true - After breeding, most migrate to highly saline lakes in the Great Basin, where they molt, feed, and accumulate fat prior to flying to wintering areas. Major migration stops include: Mono Lake, California (up to 750,000 birds at peak in fall); Malheur NWR, Oregon; Bear River NWR, Utah; Great Salt Lake, Utah (up to 1.7 million individuals using the south arm of the lake; Jehl 1988). Fall migration probably peaks October-November (Johnsgard 1987). First arrivals in northern states and western provinces occur in April.

Non-migrant

false

Locally Migrant

false

Food Comments

Diet includes aquatic insects and larvae, small fishes, crustaceans, and other small invertebrates. Feeds on surface of water or dives under. Diet mostly brine shrimp in fall at Mono Lake, California.

Reproduction Comments

Breeding begins mid-April in south, late May-June in north. In Minnesota, nest initiation dates ranged from late May through the third week in July; nesting was moderately to highly synchronous within a colony (Boe 1994). Both adults, in turn, incubate an average of 3-4 eggs for 20-22 days. Young reportedly are independent in 3 weeks. Usually nests in colony (100 pairs on 1 lake is not unusual) on larger lakes. In Minnesota, colonies included 15 to 580+ nests, with 3-41 nests per 100 sq m (Boe 1994).

Ecology Comments

Gregarious at all times of the year. Several hundred thousand may congregate in late summer and fall at Mono Lake, California. Mass downings of migrants sometimes occur in southern Utah in December (Condor 95:470-473). In Minnesota, waves generated by high winds destroyed 44% of 2370 nests examined; nest predation rate was very low (Boe 1994).

Length

Weight

297

Conservation Status

NatureServe Global Status Rank

Global Status Last Reviewed

1996-11-20

Global Status Last Changed

1996-11-20

Other Status

LC - Least concern

Distribution

Conservation Status Map

Global Range

H - >2,500,000 square km (greater than 1,000,000 square miles) - H - BREEDING: southwestern Canada east to Manitoba, south to northern Baja California, central Arizona, northern New Mexico, and southern Texas, east to Illinois, Iowa, Nebraska, Kansas, and Oklahoma, south locally to central Mexico (Chihua, Nayarit, Jalisco, Puebla); in South America (formerly) on temperate lakes in the eastern Andes of Colombia (considered full species, P. ANDINUS, by some). NON-BREEDING: mainly southern British Columbia to Guatemala on coast, and inland north to central California, northern Nevada, northern Utah, northern New Mexico, and central Texas inland; recently reported rarely but possibly regularly to El Salvador (see Stiles and Skutch 1989). The highest concentration in winter is on the Salton Sea, California (Root 1988). Also occurs in Eurasia and Africa.

Global Range Code

Global Range Description

>2,500,000 square km (greater than 1,000,000 square miles)

ELEMENT_GLOBAL.2.100013