Podiceps grisegena

Populations vary in bill and body size; European and West Asian birds substantially smaller than North American and East Asian birds. European and West Asian grebes also show darker back, cheeks, and neck, and less yellow in bill than East Asian and North American birds. Two subspecies recognized: P. g. grisegena for European and West Asian populations and P. g. holboellii, for East Asian and North American populations (Stout and Neuchterlein 1999).

Holarctic. Breeding range extends from Alaska and western and south-central Canada south to Washington, Montana, northeastern South Dakota, Minnesota, and rarely elsewhere in northern United States; also Europe and northern Asia. During the nonbreeding season, the range extends coastally from Alaska to southern California and from Nova Scotia to central Florida (mainly north of Chesapeake Bay), casually along Gulf Coast; also in the Old World. Areas of highest winter density in North America include waters around Vancouver Island in the Strait of Georgia and the Bay of Fundy (Root 1988).

This species is represented by a large number of occurrences (subpopulations).

Reduced productivity and population declines in portions of North America have been attributed to organochlorine residues, recent increases in unnatural predators (raccoon), and human recreational activities (DeSmet 1987). Commercial gill-nets are a potential source of mortality. Habitat degradation has occurred in the breeding range as a result of development near and drainage of wetlands and potholes (Stout and Neuchterlein 1999). Red-necked grebes are vulnerable during winter to marine oil spills (Stout and Neuchterlein 1999).

Global climate may effect lake dynamics and phenology, particularly in northern breeding populations. Breeding pairs need 8-11 days between arrival and onset of clutch initiation. A late spring could potentially shift the onset date of clutch initiation well into summer, jeopardizing chick survival and fledgling success (Bucher 1997).