The black-necked grebe or eared grebe (Podiceps nigricollis) is a member of the grebe family of water birds. It was described in 1831 by Christian Ludwig Brehm. Its breeding plumage features distinctive ochre-coloured feathers which extend behind its eye and over its ear coverts. The rest of the upper parts, including the head, neck, and breast, are coloured black to blackish brown. The flanks are tawny rufous to maroon-chestnut, and the abdomen is white. In its non-breeding plumage, this bird has greyish-black upper parts, including the top of the head and a vertical stripe on the back of the neck. The flanks are also greyish-black. The rest of the body is a white or whitish colour. The juvenile has more brown in its darker areas. This species is present in parts of Africa, Eurasia, and the Americas.
The black-necked grebe uses multiple foraging techniques. Insects, which make up the majority of this bird's diet, are caught either on the surface of the water or when they are in flight; this species occasionally practices foliage gleaning. This grebe dives to catch crustaceans, molluscs, tadpoles, and small frogs and fish. When moulting at saline lakes, this bird feeds mostly on brine shrimps (such as Artemia franciscana, and "Artemia parthenogenetica"). The black-necked grebe makes a floating cup nest on an open lake. The nest cup is covered with a disc. This nest is located both in colonies and by itself. During the breeding season, which varies depending on location, this species will lay one (sometimes two) clutch of three to four eggs. The number of eggs is sometimes larger due to conspecific brood parasitism. After a 21-day incubation period, the eggs hatch, and then the nest is deserted. After about 10 days, the parents split up the chicks between themselves. After this, the chicks become independent in about 10 days, and fledge in about three weeks.
Although it generally avoids flight, the black-necked grebe travels as far as during migration. In addition, it becomes flightless for at least a month after completing a migration to reach an area where it can moult safely. During this moult, the grebe can double in weight. The migration to reach these areas can be dangerous, sometimes with thousands of grebe deaths. In spite of this, it is classified as a least concern species by the International Union for Conservation of Nature (IUCN). It is likely that this is the most numerous grebe in the world. There are potential threats to it, such as oil spills, but these are not likely to present a major risk to the overall population.
Taxonomy This species was first described by Carl Ludwig Hablitz in 1783 as Colymbus caspicus, from a bird in Bandar-e Anzali. This was originally thought to be a synonym for the horned grebe, until Erwin Stresemann discovered that the description applied more to the black-necked grebe in 1948. Before this, the earliest description was thought to be by Christian Ludwig Brehm in 1831, who gave this bird its current scientific name of Podiceps nigricollis from a German bird. To resolve this, the International Commission on Zoological Nomenclature suppressed the name Colymbus caspicus. The genus name Dytes is sometimes used for this species and its closest relatives, a placement which was preferred by Robert Ridgway in 1881.
Subspecies There are currently three accepted subspecies.
Summer Winter Scientific name Common name Distribution NotesAltlußheim, Baden-Württemberg, Germany Borith Lake, Gilgit-Baltistan, Pakistan P. n. nigricollis Brehm, 1831 Black-necked grebe (Eurasian) Across the temperate Palearctic from western Europe to eastern Asia, wintering further south to northern Africa, the Persian Gulf, and southern China. Nominate subspecies. East African birds (Ethiopia, Kenya) are included in this subspecies, rather than P. n. gurneyi, by some authors.Grassy Park, Cape Town, Western Cape, South Africa Cape Town, Western Cape, South Africa P. n. gurneyi (Roberts, 1919) Black-necked grebe (African) Eastern and southern Africa from Ethiopia to South Africa; resident Greyer head and upper parts; smallest subspecies.Note that HBW erroneously states this subspecies does not have a winter plumage; this is contradicted by regional field guides, which illustrate and describe it, as well as by photographic evidence. Tule Lake NWR, Klamath Basin, California, USA San Luis Obispo, California, USA P. n. californicus (Heermann, 1854) Eared grebe Interior southwestern Canada and the western United States, wintering on the Pacific coast and inland waters from southwestern Canada south to Guatemala, occasional east to the Atlantic coast. Longer bill than other the subspecies.
This bird is closely related to the South American silvery grebe and Junin grebe. The extinct Colombian grebe P. andinus is particularly closely related, and is often considered to be a subspecies of P. nigricollis; it is genetically nested within it, with P. n. californicus being more closely related to P. andinus, than it is to P. n. nigricollis.
Etymology The generic name, Podiceps, comes from two Latin words: , meaning or , and meaning .Ogilvie & Rose (2003), p. 98. This is a reference to the attachment point of the bird's legs at the extreme back end of its body. The specific epithet nigricollis is Latin for : means and means . The subspecies epithet californicus comes from "California", while gurneyi comes from the name of British ornithologist John Henry Gurney Sr.
"Black-necked grebe" has been designated the official name by the International Ornithological Committee (IOC). Both common names for this species refer to features visible when the bird is in its breeding plumage; in such plumage, it has an all-black neck and a spray of golden plumes on each side of its head. The name "eared grebe" is nearly a century older than the name "black-necked grebe". The latter was first used in 1912 by Ernst Hartert, in an effort to bring the common name of the species in line with its scientific name,Ogilvie & Rose (2003), pp. 102–103. and/or to avoid the long history of confusion between the vernacular name "eared" with the scientific name of the horned grebe Podiceps auritus (auritus, Latin, 'eared'). The name "eared grebe" is still used in North America to refer to this bird.
Description The black-necked grebe usually measures between in length and has a wingspan range of in P. n. nigricollis, and in P. n. californicus. It weighs , with males being on average heavier than females. The nominate subspecies in breeding plumage has the head, neck, breast, and upper parts coloured black to blackish brown, with the exception of the ochre-coloured fan of feathers extending behind the eye over the eye-coverts and sides of the nape. The eye is a vivid bright red, with a narrow and paler yellow ring on the inner parts of the eye and an orange-yellow to pinkish-red . The thin, upturned bill, on the other hand, is black, and is connected to the eye by a blackish line starting at the . Sometimes, the foreneck can be found to be mostly tinged brown. The is blackish to drab brown in colour and has a white patch formed by the secondaries and part of the inner primaries. The flanks are coloured tawny rufous to maroon-chestnut and have the occasional blackish fleck. The and abdomen is white, with an exception to the former being the dark tertials and the mostly pale grey-brown outer primaries. The legs are a dark greenish grey. The sexes are similar.
In non-breeding plumage, the nominate has greyish-black upper parts, cap, nape, and hindneck, with the colour on the upper portion of the latter being contained in a vertical stripe. The dark colour of the cap reaches below the eye and can be seen, diffused, to the ear-coverts. Behind the ear-coverts on the sides of the neck, there are white ovals. The rest of the neck is grey to brownish-grey in colour and has white that varies in amount. The breast is white, and the abdomen is whitish. The flanks are coloured in a mix of blackish-grey with white flecks. The colour of the bill when not breeding differs from that of the breeding plumage, with the former being significantly more grey.
The juvenile black-necked grebe is similar to the non-breeding adult. There are differences, however, including the fact that the dark areas are usually more brownish in the juvenile, with less black. The are often tinged pale grey, with whitish marks behind the eye. On the sides of the head and upper neck, there is a buffy or tawny tinge. The chick is downy and has a blackish-grey head with stripes and spots that are white or pale buff-grey. The throat and foreneck are largely pale. The upper parts are mostly dark grey in colour, and the abdomen is white.
The subspecies P. n. californicus usually has a longer bill compared to the nominate, and has brown-grey inner primaries during the breeding season. When not breeding, the nominate has diffuse and pale lores less often than P. n. californicus. The African subspecies P. n. gurneyi is the smallest of the three subspecies, in addition to having a greyer head and upper parts. The adult of this subspecies also has a rufous-brown tinge on its lesser wing-coverts.
Vocalisations When breeding, the black-necked grebe gives a quiet "ooeek" that ascends in pitch from an already high pitch. This call is also used as a territorial call, in addition to a low and fast trill, which itself is also used during courtship. Another call is a short "puuii" or "wit". This grebe is silent when it is not the breeding season and when it is feeding or resting.
Distribution and habitat This species breeds in vegetated areas of freshwater lakes across temperate Europe, Asia, eastern and southern Africa, interior southwestern Canada, and the southwest and western United States. After breeding, this bird migrates to saline lakes to moult. Then, after completing the moult and waiting for sometimes several months, it migrates to winter in places such as the south-western Palearctic and the eastern parts of both Africa and Asia. It also winters in southern Africa, another place where it breeds. In the Americas, it winters as far south as Guatemala, and occasionally further south in Central America, although larger wintering populations there are mainly restricted to islands in the Gulf of California, the Salton Sea, and Baja California. When not breeding, its habitat is primarily saline lakes, sheltered inshore seas, and coastal estuaries.
Behaviour This grebe is highly gregarious, usually forming large colonies when breeding and large flocks when not.
Breeding This species builds its floating nest in the usually shallow water of open lakes. The nest itself is anchored to the lake by plants. It is built by both the male and the female and made out of plant matter. Most of it is submerged, with the bottom of the shallow cup usually being level with the water. Above the cup, there is a flat disc. This grebe nests both in colonies and by itself. When it does not nest by itself, it will often nest in mixed-species colonies made up of black-headed gulls, ducks, and various other waterbirds. The space between the nests in these colonies is often . Whether it nests in colonies or not has an effect on the dimensions of the nest. When the bird is not in a colony, the nest has an average diameter of , although this can vary, with nests ranging from about to over . This is compared to nests in colonies, which have an average diameter of about . It is suggested that rarely some pairs of this grebe will steward over multiple nests when in colonies.