genus
Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...
of birds in the
grebe
Grebes () are aquatic diving birds in the order (biology), order Podicipediformes (). Grebes are widely distributed freshwater birds, with some species also found in sea, marine habitats during Bird migration, migration and winter. Most grebes f ...
family. The genus name comes from
Latin
Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...
, "rear-end" and ', "foot", and is a reference to the placement of a grebe's legs towards the rear of its body.
It has representatives breeding in all continents except Antarctica. Some species are partially or entirely migratory, moving in winter to the coast or warmer climates. Most species are widespread and overall common, but three South American species each are restricted to a single country; two of them are seriously threatened and a third is already extinct.
They breed in vegetated areas of freshwater lakes, nesting on the water's edge, since their legs are set too far back for easy walking. Usually two eggs are laid, and the striped young may be carried on the adult's back. All the genus are excellent swimmers and divers, and pursue their fish prey underwater. Adults have striking breeding plumage, with no difference between the sexes. In winter, the plumage is subdued whites and greys.
Systematics
The genus ''Podiceps'' was erected by the English naturalist John Latham in 1787. The
type species
In International_Code_of_Zoological_Nomenclature, zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the spe ...
was subsequently designated as the
great crested grebe
The great crested grebe (''Podiceps cristatus'') is a member of the grebe family of water birds. The bird is characterised by its distinctive appearance, featuring striking black, orange-brown, and white plumage, and elaborate courtship displa ...
(''Podiceps cristatus''). The genus name combines variants on the Latin , roughly meaning "rear-end", and ', meaning "foot".
The black-necked, Colombian, silvery, and Junin grebes are very closely related and were formerly sometimes separated as the genus ''Dyas''. The great grebe has also sometimes been separated as the sole member of the genus ''Podicephorus''; there is also genetic evidence that it is more closely related to the '' Aechmophorus'' grebes than it is to the rest of the genus ''Podiceps''.
The genus contains nine species:
The chicks of all ''Podiceps'' grebes (including ''P. major'', but not those of the related genus '' Aechmophorus'') have boldly striped heads, with alternating black and white stripes; they are often colloquially called "humbugs" from their resemblance to humbug sweets. They lose these markings as they mature during their first winter.
Fossils
One of the very oldest
fossil
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserve ...
grebes known to date actually belongs to this genus. Regarding grebes, the fossil record leaves much to be desired, being quite complete for the last 5 million years before present but very incomplete before the
Pliocene
The Pliocene ( ; also Pleiocene) is the epoch (geology), epoch in the geologic time scale that extends from 5.33 to 2.58Podiceps arndti'' Chandler, 1990 (Piacenzian stage of North America)
* †'' Podiceps csarnotanus'' Kessler, 2009 (Piacenzian stage of Europe)
* †'' Podiceps discors'' Murray, 1967 (Piacenzian stage of North America)
* †'' Podiceps dixi'' Brodkorp, 1963 (
Chibanian
The Chibanian, more widely known as the Middle Pleistocene (its previous informal name), is an Age (geology), age in the international geologic timescale or a Stage (stratigraphy), stage in chronostratigraphy, being a division of the Pleistocen ...
Zanclean
The Zanclean is the lowest stage or earliest age on the geologic time scale of the Pliocene. It spans the time between 5.332 ± 0.005 Ma (million years ago) and 3.6 ± 0.005 Ma. It is preceded by the Messinian Age of the Miocene Epoch, and f ...
age of North Carolina, United States)
* †'' Podiceps miocenicus'' Kessler, 1984 (
Tortonian
The Tortonian is in the geologic time scale an age or stage of the late Miocene that spans the time between 11.608 ± 0.005 Ma and 7.246 ± 0.005 Ma (million years ago). It follows the Serravallian and is followed by the Messinian.
The Tort ...
age of Moldova)
* †'' Podiceps oligoceanus'' (Shufeldt, 1915) (Aquitanian age of North America)
* †'' Podiceps parvus'' (Shufeldt, 1913) (Gelasian to the Calabrian stages of North America)
* †'' Podiceps pisanus'' (Shufeldt, 1913) (Piacenzian stage of Italy)
* †'' Podiceps solidus'' Kuročkin, 1985 (Zanclean age of Western Mongolia)
* †'' Podiceps subparvus'' (Miller & Bowman, 1958)
*''Podiceps''? sp. (Late Pliocene of WC USA)
*''Podiceps'' sp. (Early Pleistocene of Dursunlu, Turkey)
Among the material assigned to ''P. parvus'' were bones of another species, which may or may not belong in this genus.