The horned grebe or Slavonian grebe (Podiceps auritus) is a relatively small waterbird in the family Podicipedidae. There are two known subspecies: P. a. auritus, which breeds in the Palearctic, and P. a. cornutus, which breeds in North America. The Eurasian subspecies is distributed over most of northern Europe and the Palearctic, breeding from Greenland to western China. The North American subspecies spans most of Canada and some of the United States. The species got its name from large patches of yellowish feathers located behind the eyes, called "horns", that the birds can raise and lower at will.
Description
Horned grebes can be easily recognised by its red-and-black alternate (breeding) plumage, its black-and-white basic (non-breeding) plumage, and its characteristic "horns". It is 31–38 cm long, has a wingspan 55–74 cm wide and weighs 300–570 g. It has a moderately long neck, flat forehead and a rear crown of black feathers. Its beak is straight and pointy with a white tip. Both subspecies are physically similar, with P. a. auritus (Palearctic) appearing darker than P. a. cornutus (North America), which has light grey feathers on its back, which are inconspicuous or absent in P. a. auritus. The horned grebe is often confused with the black-necked grebe, which is similar in size and colouring but differentiates by a steeper forehead, a more slender bill and a fluffier rump.
The alternate (breeding) plumage of the horned grebe has bright erectable "horns", black fan-shaped cheek feathers and an overall red-and-black colour. The neck, flanks, lores and upper-chest are chestnut brown, while the crown and back are black. The belly is a dull white. Males are slightly larger and brighter than females but are generally indistinguishable.
The basic (non-breeding) plumage is overall black and white. The neck, chest and cheeks are white, while the back and crown are a dull black-grey. The border between the crown and the cheeks extend in a straight line behind the eyes. The basic plumage does not have the "horns".
Juveniles appear similar to a non-breeding adult except they are a slightly duller shade of white and their back is tinged with brown. The line separating the cheeks and crown is less distinct and their beak is paler. The chicks are fluffy, with a dull grey back, a white belly and interesting black-and-white facial striping.
Taxonomy
Subspecies
P. a. auritus, (Linnaeus, 1758), temperate Eurasia
P. a. cornutus, (Gmelin, 1789), North America
Related species
Black-necked grebe (Podiceps nigricollis) Red-necked grebe (Podiceps grisegena) Great crested grebe (Podiceps cristatus)
Paleontology
A handful of fossil species, such as the Pliocene aged P. howardae, P. pisanus and P. solidus, and the Pleistocene aged P. dixi have been described to be related to or perhaps some of them might be pre-Holocene material of the horned grebe. However while P. howardae and P. dixi are regularly recognized as fossil material of the horned grebe by some authors, P. pisanus and P. solidus are argued to be valid species that are close to the ancestry of the horned grebe.
Distribution and habitat
The horned grebe is distributed in Eurasia and North America. In Eurasia, it breeds in a few isolated locations in Greenland (uncommon), Iceland, Scotland and northwestern Norway, while extensively from southeastern Norway to western China. It winters along the coasts of Iceland, Norway and the British Isles down towards the Mediterranean, the Black Sea and the Caspian Sea. In eastern Asia, the horned grebe winters along the coasts of China, Korea and Japan.
In North America, it is restricted to the northwestern region of the continent, with 92% of its distribution located in Canada. The total North American range spans from south-central Alaska to northwestern Ontario. It breeds as far north as the Yukon and southern Nunavut to northwestern states, from Washington to Minnesota. Additionally, there is a small population who breed annually on the Magdalene Islands of Quebec. Its wintering range is also primarily coastal from southern Alaska down to the northern Gulf of California. Its eastern overwintering range is from southern Nova Scotia, down to the Florida Keys and sometimes west to Texas.