Taxonomy
Grebes are small to medium-large water birds with lobed, rather than webbed, toes. There are several genera, of which the most widespread is Podiceps with nine species, one recently extinct. The Red-necked Grebe's closest relative is the fish-eating Great Crested Grebe of Europe and western Asia. It is possible that the Red-necked Grebe originally evolved in North America and later spread to Europe, where a change of diet to include more insects helped to reduce competition with its larger cousin. Fossils of the species dating to the middle Pleistocene have been found in Italy.
The genus name Podiceps comes from Latin podicis, "vent" or "anus", and pes, "foot", and is a reference to the placement of a grebe's legs towards the rear of its body. The species name grisegena is from Latin griseus (grey) and gena (cheek) and refers to the face pattern of the breeding adult.
The Red-necked Grebe has two subspecies, the nominate subspecies P. g. grisegena in Europe and western Asia, and P. g. holboelii (Holboell's Grebe, named for Danish explorer of Greenlandic birds Carl Peter Holbøll) in North America and eastern Siberia. The east Asian birds have slightly smaller bills than the American form, although the differences are too small to merit separation as a third subspecies.
Read more about this topic: Red-necked Grebe