The red-necked grebe (''Podiceps grisegena'') is a
migratory aquatic bird found in the
temperate regions
In geography, the temperate climates of Earth occur in the middle latitudes (23.5° to 66.5° N/S of Equator), which span between the tropics and the polar regions of Earth. These zones generally have wider temperature ranges throughout t ...
of the northern hemisphere. Its wintering habitat is largely restricted to calm waters just beyond the waves around ocean coasts, although some birds may winter on large lakes.
Grebe
Grebes () are aquatic diving birds in the order Podicipediformes . Grebes are widely distributed freshwater birds, with some species also found in marine habitats during migration and winter. Some flightless species exist as well, most notably ...
s prefer shallow bodies of fresh water such as lakes, marshes or fish-ponds as breeding sites.
The red-necked grebe is a nondescript dusky-grey bird in winter. During the breeding season, it acquires the distinctive red neck plumage, black cap and contrasting pale grey face from which its name was derived. It also has an elaborate
courtship display
A courtship display is a set of display behaviors in which an animal, usually a male, attempts to attract a mate; the mate exercises choice, so sexual selection acts on the display. These behaviors often include ritualized movement ("dances"), ...
and a variety of loud mating calls. Once paired, it builds a nest from water plants on top of floating vegetation in a shallow lake or bog.
Like all grebes, the Red-necked is a good swimmer, a particularly swift diver, and responds to danger by diving rather than flying. The feet are positioned far back on the body, near the tail, which makes the bird ungainly on land. It dives for fish or picks insects off vegetation; it also swallows its own feathers, possibly to protect the digestive system. The
conservation status
The conservation status of a group of organisms (for instance, a species) indicates whether the group still exists and how likely the group is to become extinct in the near future. Many factors are taken into account when assessing conservation ...
of its two subspecies—''P. g. grisegena'' found in Europe and western Asia, and the larger ''P. g. holboelii'' (formerly Holbœll grebe), in North America and eastern
Siberia
Siberia ( ; rus, Сибирь, r=Sibir', p=sʲɪˈbʲirʲ, a=Ru-Сибирь.ogg) is an extensive geographical region, constituting all of North Asia, from the Ural Mountains in the west to the Pacific Ocean in the east. It has been a part of ...
—is evaluated as
Least Concern
A least-concern species is a species that has been categorized by the International Union for Conservation of Nature (IUCN) as evaluated as not being a focus of species conservation because the specific species is still plentiful in the wild. T ...
, and the global population is stable or growing.
Taxonomy
The red-necked grebe was described by the French polymath
Georges-Louis Leclerc, Comte de Buffon
Georges-Louis Leclerc, Comte de Buffon (; 7 September 1707 – 16 April 1788) was a French naturalist, mathematician, cosmologist, and encyclopédiste.
His works influenced the next two generations of naturalists, including two prominent Fr ...
in 1781 in his ''Histoire Naturelle des Oiseaux''. The bird was also illustrated in a hand-coloured plate engraved by
François-Nicolas Martinet François-Nicolas Martinet (1731 - 1800) was a French engineer, engraver and naturalist.
Martinet engraved the plates for numerous works on natural history, especially ornithology. Notable in particular are those for ''l'Ornithologia, sive Synop ...
in the ''Planches Enluminées D'Histoire Naturelle'' which was produced under the supervision of
Edme-Louis Daubenton
Edme-Louis Daubenton (12 August 1730 – 12 December 1785) was a French naturalist.
Daubenton was the cousin of another French naturalist, Louis Jean-Marie Daubenton. Georges-Louis Leclerc, the Comte de Buffon engaged Edme-Louis Daubenton to su ...
to accompany Buffon's text. Neither the plate caption nor Buffon's description included a scientific name but in 1783 the Dutch naturalist
Pieter Boddaert
Pieter Boddaert (1730 – 6 May 1795) was a Dutch physician and natural history, naturalist.
Early life, family and education
Boddaert was the son of a Middelburg jurist and poet by the same name (1694–1760). The younger Pieter obtained his M.D ...
coined the
binomial name
In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...
''Colymbus grisegena'' in his catalogue of the ''Planches Enluminées''. The
type locality was subsequently designated as France. The red-necked grebe is now placed in the
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...
''
Podiceps
''Podiceps'' is a genus of birds in the grebe family. The genus name comes from Latin ''podicis'', "rear-end" and ''ped'', "foot", and is a reference to the placement of a grebe's legs towards the rear of its body.
It has representatives breed ...
'' that was erected by the English naturalist
John Latham in 1787.
The genus name ''Podiceps'' comes from
Latin
Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...
''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.
[Ogilvie & Rose (2002) 98] The species name ''grisegena'' is from Latin ''griseus'' (grey) and ''gena'' (cheek) and refers to the face pattern of the breeding adult.
[Ogilvie & Rose (2002) 102]
Grebes are small to medium-large water birds with lobed, rather than webbed, toes. There are several
genera
Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclat ...
, of which the most widespread is ''
Podiceps
''Podiceps'' is a genus of birds in the grebe family. The genus name comes from Latin ''podicis'', "rear-end" and ''ped'', "foot", and is a reference to the placement of a grebe's legs towards the rear of its body.
It has representatives breed ...
'' with nine species, one recently extinct. The red-necked grebe's closest relative is the fish-eating
great crested grebe
The great crested grebe (''Podiceps cristatus'') is a member of the grebe family of water birds noted for its elaborate mating display.
Taxonomy
The great crested grebe was formally described by the Swedish naturalist Carl Linnaeus in 1758 in t ...
of Europe and western Asia.
[Ogilvie & Rose (2002) 8–9] 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.
[Johnsgard, PA (1987) 130–135] Fossils of the species dating to the middle
Pleistocene
The Pleistocene ( , often referred to as the ''Ice age'') is the geological Epoch (geology), epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fina ...
have been found in Italy.
The red-necked grebe has two subspecies, the
nominate subspecies
In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (morphology), but that can successfully interbreed. Not all species ...
''P. g. grisegena'' in Europe and western Asia, and ''P. g. holboelii'' (Holboell's grebe, named for Danish explorer of
Greenland
Greenland ( kl, Kalaallit Nunaat, ; da, Grønland, ) is an island country in North America that is part of the Kingdom of Denmark. It is located between the Arctic and Atlantic oceans, east of the Canadian Arctic Archipelago. Greenland is t ...
ic birds
Carl Peter Holbøll
Carl Peter Holbøll (1795–1856) was an officer in the Danish Royal Navy, Greenland colonial officer and explorer of the Greenlandic fauna.
Holbøll served as Royal Inspector of Colonies and Whaling in North Greenland (1825–1828), then Inspec ...
) in North America and eastern
Siberia
Siberia ( ; rus, Сибирь, r=Sibir', p=sʲɪˈbʲirʲ, a=Ru-Сибирь.ogg) is an extensive geographical region, constituting all of North Asia, from the Ural Mountains in the west to the Pacific Ocean in the east. It has been a part of ...
. 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.
[Ogilvie & Rose (2002) 57–60]
Description
The red-necked grebe is a medium-large grebe, smaller than the great crested grebe of
Eurasia
Eurasia (, ) is the largest continental area on Earth, comprising all of Europe and Asia. Primarily in the Northern and Eastern Hemispheres, it spans from the British Isles and the Iberian Peninsula in the west to the Japanese archipelago a ...
, and the
western
Western may refer to:
Places
*Western, Nebraska, a village in the US
*Western, New York, a town in the US
*Western Creek, Tasmania, a locality in Australia
*Western Junction, Tasmania, a locality in Australia
*Western world, countries that id ...
and
Clark's grebe
Clark's grebe (''Aechmophorus clarkii'') is a North American waterbird species in the grebe family. Until the 1980s, it was thought to be a pale Polymorphism (biology), morph of the western grebe, which it resembles in size, range, and behavior. ...
s of North America, but noticeably larger than other northern grebe species.
[Snow & Perrin (1998) 17–20][Sibley (2000) 29] The adult of the nominate European subspecies is long with a average wingspan,
[Snow & Perrin (1998) 20–22] and weighs .
In breeding plumage, it has a black cap that extends below the eye, very pale grey cheeks and throat, a rusty red neck, dark grey back and flanks, and white underparts. The eyes are dark brown and the long, pointed bill is black with a yellow base.
[Mullarney ''et al.'' 18]
The winter plumage of the red-necked grebe is duskier than that of other grebes; its dark grey cap is less defined, and merges into the grey face, and a pale crescent that curves around the rear of the face contrasts with the rest of the head. The front of the neck is whitish or light grey, the hind neck is darker grey, and the yellow of the bill is less obvious than in summer.
Although the red-necked grebe is unmistakable in breeding plumage, it is less distinctive in winter and can be confused with similar species. It is larger than the
Slavonian (horned) grebe, with a relatively larger bill and a grey, rather than white face.
[ It is closer in size to the Eurasian great crested grebe, but that species is longer-necked, has a more contrasting head pattern, and always shows white above the eye.]
The sexes are similar in appearance, although the male averages heavier than the female.[ Chicks have a striped head and breast, and older juveniles have a striped face, diffuse blackish cap, pale red neck and extensive yellow on the bill.]
The subspecies ''P. g. holboelii'' is larger than the nominate race at length, with a wingspan, and a weight of .[Ogilvie & Rose (2002) 92] The plumages are the same as those of the nominate race, although the adult's bill is more extensively yellow. The difference in size between the sexes is greater than for this subspecies that for ''P. g. grisegena''.[
The red-necked grebe flies with its long neck extended and its large feet trailing behind the body, which gives it a stretched-out appearance.][Fjeldsa (2004) 140] The relatively small wings are grey with white secondaries, and beat very rapidly. Its small wing area means that the grebe is unable to take off from land,[Fjeldsa (2004) 31] and needs a lengthy run across water to gain the speed needed for take-off.[Johnsgard (1987) 26–36] Like all grebes, the red-necked is an expert swimmer; it uses its feet for propulsion underwater, and steers by rotating its legs, since its tail is too short for this purpose.[Fjeldsa (2004) 10]
This is one of the most vocal grebes during the breeding season, but, like its relatives, it is mainly silent for the rest of the year. It has a loud, wailing or howling display call ''uooooh'', given by a single bird or a pair in duet, by night or during the day, and often from cover. Long sequences of up to 60 consecutive notes may be delivered during singing encounters between rival territorial birds. A great variety of quacking, clucking, hissing, rattling and purring calls are also given, with much individual variation.[
]
Distribution and habitat
Breeding takes place in shallow freshwater lakes, bays of larger lakes, marshes, and other inland bodies of water, often less than in extent and less than deep. The red-necked grebe shows a preference for waters in forested areas or, further north, in shrub tundra
In physical geography, tundra () is a type of biome where tree growth is hindered by frigid temperatures and short growing seasons. The term ''tundra'' comes through Russian (') from the Kildin Sámi word (') meaning "uplands", "treeless moun ...
, and favours sites with abundant emergent vegetation, such as reedbeds
A reedbed or reed bed is a natural habitat found in floodplains, waterlogged depressions and
estuaries. Reedbeds are part of a succession from young reeds colonising open water or wet ground through a gradation of increasingly dry ground. As ...
. The best breeding habitat is fish-ponds, which have an abundance of food in addition to meeting the other requirements. The American subspecies is less tied to a high aquatic plant density, and sometimes breeds on quite open lakes.[
All populations are migratory and winter mainly at sea, usually in estuaries and bays, but often well offshore where fish are within diving reach near shallow banks or islands.][ The preferred passage and wintering habitat is water less than deep with a sand or gravel bottom, scattered rocks and patches of seaweed.][ During winter, birds typically feed alone and rarely aggregate into flocks, but on migration, concentrations of over 2000 individuals may occur at favoured staging sites.][ Migration is usually at night, but may occur during the day, especially when over water. This is particularly noticeable in autumn on the Great Lakes, when up to 18,000 birds may pass ]Whitefish Point
Whitefish Point is a cape of Michigan's Upper Peninsula, United States, marking the entry point of Whitefish Bay. It is north of the unincorporated community of Paradise, Michigan.
Whitefish Point is known for the Great Lakes Shipwreck Museum, it ...
on Lake Superior
Lake Superior in central North America is the largest freshwater lake in the world by surface areaThe Caspian Sea is the largest lake, but is saline, not freshwater. and the third-largest by volume, holding 10% of the world's surface fresh wa ...
; these are thought to be Canadian breeders heading for the Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe ...
to winter. This easterly route is longer than that to the Pacific
The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continen ...
, but avoids the Rockies
The Rocky Mountains, also known as the Rockies, are a major mountain range and the largest mountain system in North America. The Rocky Mountains stretch in straight-line distance from the northernmost part of western Canada, to New Mexico in ...
.[
The breeding range of the red-necked grebe overlaps with that of the Slavonian grebe, although the latter species tends to be displaced from sites suited to both. The red-necked grebe prefers an inland temperate climate, and is less successful near coasts and in subarctic and warm temperate zones. It is usually a lowland bird, breeding below , although has nested at up to in Turkey.][
The nominate subspecies breeds from southern Sweden and Denmark through central and eastern Europe east to western Siberia, and winters mainly in the ]North
North is one of the four compass points or cardinal directions. It is the opposite of south and is perpendicular to east and west. ''North'' is a noun, adjective, or adverb indicating Direction (geometry), direction or geography.
Etymology
T ...
and Baltic Sea
The Baltic Sea is an arm of the Atlantic Ocean that is enclosed by Denmark, Estonia, Finland, Germany, Latvia, Lithuania, Poland, Russia, Sweden and the North and Central European Plain.
The sea stretches from 53°N to 66°N latitude and from ...
s, with smaller numbers in the Adriatic
The Adriatic Sea () is a body of water separating the Italian Peninsula from the Balkans, Balkan Peninsula. The Adriatic is the northernmost arm of the Mediterranean Sea, extending from the Strait of Otranto (where it connects to the Ionian Sea) ...
, Black Sea
The Black Sea is a marginal mediterranean sea of the Atlantic Ocean lying between Europe and Asia, east of the Balkans, south of the East European Plain, west of the Caucasus, and north of Anatolia. It is bounded by Bulgaria, Georgia, Roma ...
, Caspian Sea
The Caspian Sea is the world's largest inland body of water, often described as the world's largest lake or a full-fledged sea. An endorheic basin, it lies between Europe and Asia; east of the Caucasus, west of the broad steppe of Central Asia ...
, Mediterranean
The Mediterranean Sea is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean Basin and almost completely enclosed by land: on the north by Western and Southern Europe and Anatolia, on the south by North Africa, and on the e ...
and on inland lakes.[Harrison (1988) 217] ''P. g. holboelii'' breeds in North America in Alaska
Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U.S., ...
, western and central Canada, and the northern US east to Minnesota
Minnesota () is a state in the upper midwestern region of the United States. It is the 12th largest U.S. state in area and the 22nd most populous, with over 5.75 million residents. Minnesota is home to western prairies, now given over to ...
; in Asia it nests in eastern Siberia from Kamchatka
The Kamchatka Peninsula (russian: полуостров Камчатка, Poluostrov Kamchatka, ) is a peninsula in the Russian Far East, with an area of about . The Pacific Ocean and the Sea of Okhotsk make up the peninsula's eastern and wes ...
south to Hokkaido
is Japan's second largest island and comprises the largest and northernmost prefecture, making up its own region. The Tsugaru Strait separates Hokkaidō from Honshu; the two islands are connected by the undersea railway Seikan Tunnel.
The la ...
and west to Mongolia. The Asian birds winter at sea from Japan to the East China Sea
The East China Sea is an arm of the Western Pacific Ocean, located directly offshore from East China. It covers an area of roughly . The sea’s northern extension between mainland China and the Korean Peninsula is the Yellow Sea, separated b ...
, and American breeders winter in the Pacific, mainly from southern Alaska to British Columbia
British Columbia (commonly abbreviated as BC) is the westernmost province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include rocky coastlines, sandy beaches, ...
(with smaller numbers south to California
California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...
), and in the Atlantic from Newfoundland and Labrador
Newfoundland and Labrador (; french: Terre-Neuve-et-Labrador; frequently abbreviated as NL) is the easternmost province of Canada, in the country's Atlantic region. The province comprises the island of Newfoundland and the continental region ...
to Florida
Florida is a state located in the Southeastern region of the United States. Florida is bordered to the west by the Gulf of Mexico, to the northwest by Alabama, to the north by Georgia, to the east by the Bahamas and Atlantic Ocean, and to ...
. Some birds remain on the Great Lakes
The Great Lakes, also called the Great Lakes of North America, are a series of large interconnected freshwater lakes in the mid-east region of North America that connect to the Atlantic Ocean via the Saint Lawrence River. There are five lakes ...
if they are sufficiently ice-free.[ This species occurs as a rare winter ]vagrant
Vagrancy is the condition of homelessness without regular employment or income. Vagrants (also known as bums, vagabonds, rogues, tramps or drifters) usually live in poverty and support themselves by begging, scavenging, petty theft, temporar ...
in Afghanistan, Pakistan and parts of northern and western India.
Behaviour
Breeding and survival
Red-necked grebes usually nest as isolated pairs with more than between neighbouring nests, although semi-colonial nesting may occur in suitable sites, where up to 20 pairs each defend a linear territory.[ Semi-colonial breeding is more likely to occur in prime locations, such as large floating mats of vegetation with no connection to the shoreline. Such sites, safe from most predators and large enough to provide some wind and wave protection, have grebes nesting much closer than shoreline breeders, down to .] Pairs nesting in these colonies produce larger clutches of eggs, which hatch earlier in the season and result in larger broods. The territory is defended with various threat displays, including wing-spreading, hunching, and bill-thrusting;[ pairs breeding in colonies are more aggressive, less likely to leave the nest unguarded and show a greater tendency to move out of sight of the colony when not incubating.] Breeding is often in loose association with gull
Gulls, or colloquially seagulls, are seabirds of the family Laridae in the suborder Lari. They are most closely related to the terns and skimmers and only distantly related to auks, and even more distantly to waders. Until the 21st century, m ...
s or other colonial water birds.[
The ]monogamous
Monogamy ( ) is a form of Dyad (sociology), dyadic Intimate relationship, relationship in which an individual has only one Significant other, partner during their lifetime. Alternately, only one partner at any one time (Monogamy#Serial monogamy, ...
pair forms in April or May on migration or at the breeding water, and a highly vocal courtship ritual commences.[ The elaborate breeding performance includes head-shaking, a head-lowered "cat" display, parallel rushes in an upright position and mutual presentations of green weeds, and culminates in a "penguin" dance in which pair members raise the whole body upright, breast to breast.][
Like all grebes, the red-necked grebe nests near water into which it can escape, since the position of the legs far back on the body prevents fast movement on land. It often breeds further within reed beds than other grebes. The nest is a floating platform of plant matter anchored to submerged or emergent vegetation,][ in water deep, and with the bulk of nest below the water line.][ Egg-laying mainly takes place from mid-April to May in Europe,][ and somewhat later, from mid-May to June, in North America.][ Parents may leave the nest for significant periods of time during the night, possibly to evade nocturnal predators. It is unclear whether this is for self-protection or to protect the eggs by diverting attention from the nest; the clutch does not appear to suffer from this temporary abandonment, whatever the reason.]
The red-necked grebe lays four or five (range one to nine) dull white or pale blue eggs, which average in breadth, in length, and weigh about , of which 10% is shell. Parents take turns to incubate the eggs for 21–33 days until the precocial
In biology, altricial species are those in which the young are underdeveloped at the time of birth, but with the aid of their parents mature after birth. Precocial species are those in which the young are relatively mature and mobile from the mome ...
downy chicks hatch;[ they immediately climb onto the parent's back, where they spend most of their time until they are 10–17 days old.][Ogilvie & Rose (2002) 94] The young may be fed by the parents for up to 54 days after fledging,[ and can fly at 50–70 days.][ The parents do not interfere with the feeding of their chicks when they are still being carried. Later they care for the younger chicks for longer, and are aggressive with the older offspring. This equalises the post-fledging survival of all chicks, and encourages their independence. The brood may be split, so that each parent feeds only some of the chicks. This spreads the feeding demand equally between the parents.][Lott (1991) 74, 76, 146]
After breeding the adults moult
In biology, moulting (British English), or molting (American English), also known as sloughing, shedding, or in many invertebrates, ecdysis, is the manner in which an animal routinely casts off a part of its body (often, but not always, an outer ...
their wing feathers and are temporarily flightless; migration commences once the flight feather
Flight feathers (''Pennae volatus'') are the long, stiff, asymmetrically shaped, but symmetrically paired pennaceous feathers on the wings or tail of a bird; those on the wings are called remiges (), singular remex (), while those on the tail ...
s have regrown.[ The red-necked grebe is normally single-brooded, although second broods and re-nesting after a clutch has been lost may extend nesting into July or August.][
Eggs may be destroyed and chicks killed by a range of predators, including the ]raccoon
The raccoon ( or , ''Procyon lotor''), sometimes called the common raccoon to distinguish it from other species, is a mammal native to North America. It is the largest of the procyonid family, having a body length of , and a body weight of ...
in North America and the carrion crow
The carrion crow (''Corvus corone'') is a passerine bird of the family Corvidae and the genus ''Corvus'' which is native to western Europe and the eastern Palearctic.
Taxonomy and systematics
The carrion crow was one of the many species origi ...
in Europe. Pike
Pike, Pikes or The Pike may refer to:
Fish
* Blue pike or blue walleye, an extinct color morph of the yellow walleye ''Sander vitreus''
* Ctenoluciidae, the "pike characins", some species of which are commonly known as pikes
* ''Esox'', genus of ...
may take swimming chicks. On average, for each adult, 0.65 young birds are still alive by their fourth month, although the mortality rate for the adult is unknown. Red-necked grebes attempt to evade birds of prey
Birds of prey or predatory birds, also known as raptors, are hypercarnivorous bird species that actively hunt and feed on other vertebrates (mainly mammals, reptiles and other smaller birds). In addition to speed and strength, these predators ...
by diving; when feeding, dives average less than 30 seconds, although escape dives are more prolonged.[
]
Feeding
On the breeding grounds, the red-necked grebe feeds mainly on invertebrate
Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chordate ...
s including adult and larva
A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle.
The ...
l aquatic insects, such as water beetle
A water beetle is a generalized name for any beetle that is adapted to living in water at any point in its life cycle. Most water beetles can only live in fresh water, with a few marine species that live in the intertidal zone or littoral zone. Th ...
s and dragonfly
A dragonfly is a flying insect belonging to the infraorder Anisoptera below the order Odonata. About 3,000 extant species of true dragonfly are known. Most are tropical, with fewer species in temperate regions. Loss of wetland habitat threate ...
larvae, crayfish
Crayfish are freshwater crustaceans belonging to the clade Astacidea, which also contains lobsters. In some locations, they are also known as crawfish, craydids, crawdaddies, crawdads, freshwater lobsters, mountain lobsters, rock lobsters, mu ...
and mollusc
Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is esti ...
s. Fish (such as smelt
Smelt may refer to:
* Smelting, chemical process
* The common name of various fish:
** Smelt (fish), a family of small fish, Osmeridae
** Australian smelt in the family Retropinnidae and species ''Retropinna semoni''
** Big-scale sand smelt ''At ...
) may be important locally or seasonally, especially for the American subspecies, and crustacean
Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group ...
s can constitute up to 20% of the grebe's diet. Birds breeding at the coast often make foraging flights to inland lakes or offshore areas to feed.[
Aquatic prey is obtained by diving or by swimming on surface with the head submerged, and terrestrial insects and their larvae are picked off vegetation.][ A line slanting downward from the eye to the tip of the opened lower mandible may be used for sighting on prey before diving or when swimming under water. The grebe probably opens its bill and looks down the eye-line toward its target.]
European breeders, which have to compete with the larger great crested grebe for fish, eat a greater proportion of invertebrates than the longer-billed American subspecies, although both races eat mainly fish in winter.[ Birds of the nominate subspecies from the northernmost breeding populations in ]Finland
Finland ( fi, Suomi ; sv, Finland ), officially the Republic of Finland (; ), is a Nordic country in Northern Europe. It shares land borders with Sweden to the northwest, Norway to the north, and Russia to the east, with the Gulf of B ...
and Russia, beyond the range of great crested grebe, have a longer and more slender bill than those further south, reflecting a greater proportion of fish in the diet where their main competitor is absent. If food is scarce, parents may desert unhatched eggs, or allow the smallest chicks to starve, although the latter strategy appears not to be particularly efficient in protecting the older chicks.
Like other grebes, the red-necked grebe ingests large quantities of its own feathers, which remain in the bird's stomach.[ Feathers are not only swallowed by adults, mainly during self-preening, but are often fed to the young, sometimes within a day of hatching. These feathers soon decompose into a felt-like, amorphous mass.][Johnsgard (1987) 37–53] The function of the feathers in the stomach is unknown, although it has been suggested that they help to protect the lower digestive tract from bones and other hard, indigestible material.[
]
Status
The red-necked grebe has a large range, estimated at 1–10 million square kilometres (0.4–3.8 million square miles), and a global population of 150,000–370,000 individuals, with ''P. g. holboellii'' about twice as numerous as the nominate race.[Ogilvie & Rose (2002) 96] The population trend has not been quantified, but it is not believed to meet the thresholds for the population decline criterion (declining more than 30% in ten years or three generations) of the IUCN Red List
The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is the world's most comprehensive inventory of the global conservation status of biol ...
. For these reasons, the species is evaluated as Least Concern
A least-concern species is a species that has been categorized by the International Union for Conservation of Nature (IUCN) as evaluated as not being a focus of species conservation because the specific species is still plentiful in the wild. T ...
.
The red-necked grebe is one of the species to which the ''Agreement on the Conservation of African-Eurasian Migratory Waterbirds'' (AEWA
The Agreement on the Conservation of African-Eurasian Migratory Waterbirds, or African-Eurasian Waterbird Agreement (AEWA) is an independent international treaty developed under the auspices of the United Nations Environment Programme's Conventio ...
) applies. Parties to the Agreement are required to engage in a wide range of conservation strategies which are describes in a detailed action plan. The plan is intended to address key issues such as species and habitat conservation, management of human activities, research, education, and implementation.
The Red-necked Grebe was hunted by humans in northern Europe in the Mesolithic
The Mesolithic (Greek: μέσος, ''mesos'' 'middle' + λίθος, ''lithos'' 'stone') or Middle Stone Age is the Old World archaeological period between the Upper Paleolithic and the Neolithic. The term Epipaleolithic is often used synonymous ...
and Paleolithic
The Paleolithic or Palaeolithic (), also called the Old Stone Age (from Greek: παλαιός ''palaios'', "old" and λίθος ''lithos'', "stone"), is a period in human prehistory that is distinguished by the original development of stone too ...
periods, but there is no evidence that there is any significant level of hunting at the present time.[ In North America, there are potential threats from pollutants such as ]polychlorinated biphenyls
Polychlorinated biphenyls (PCBs) are highly carcinogenic chemical compounds, formerly used in industrial and consumer products, whose production was banned in the United States by the Toxic Substances Control Act of 1976, Toxic Substances Contro ...
(PCBs) and pesticides
Pesticides are substances that are meant to control pests. This includes herbicide, insecticide, nematicide, molluscicide, piscicide, avicide, rodenticide, bactericide, insect repellent, animal repellent, microbicide, fungicide, and lampric ...
such as DDT
Dichlorodiphenyltrichloroethane, commonly known as DDT, is a colorless, tasteless, and almost odorless crystalline chemical compound, an organochloride. Originally developed as an insecticide, it became infamous for its environmental impacts. ...
which cause reduced reproductive success due to egg sterility and eggshell thinning. Breeding areas may be threatened by the modification and degradation of lakes and by human disturbance from water-based recreational activities.[ There is no evidence to suggest that these threats could result in a significant risk to the overall population; more than 70% of North American red-necked grebes breed in Canada, where the population is stable or increasing.][
]
Notes
References
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* Root, Terry Louise. (1988). ''Atlas of Wintering North American Birds: An Analysis of Christmas Bird Count Data''. Chicago: University of Chicago Press. .
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External links
Red-necked Grebe - ''Podiceps grisegena''
- USGS Patuxent Bird Identification InfoCenter
Flicker Field Guide Birds of the World
Photographs
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{{Featured article
red-necked grebe
The red-necked grebe (''Podiceps grisegena'') is a migratory aquatic bird found in the temperate regions of the northern hemisphere. Its wintering habitat is largely restricted to calm waters just beyond the waves around ocean coasts, although ...
Holarctic birds
red-necked grebe
The red-necked grebe (''Podiceps grisegena'') is a migratory aquatic bird found in the temperate regions of the northern hemisphere. Its wintering habitat is largely restricted to calm waters just beyond the waves around ocean coasts, although ...
Taxa named by Pieter Boddaert