Grebes () are aquatic diving birds in the
order
Order, ORDER or Orders may refer to:
* Categorization, the process in which ideas and objects are recognized, differentiated, and understood
* Heterarchy, a system of organization wherein the elements have the potential to be ranked a number of d ...
Podicipediformes .
Grebes are widely distributed
freshwater
Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. Although the term specifically excludes seawater and brackish water, it does in ...
birds, with some species also found in
marine habitats during
migration and winter. Some flightless species exist as well, most notably in stable lakes. The order contains a single
family
Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...
, the Podicipedidae, which includes 22
species
In biology, a species is the basic unit of Taxonomy (biology), classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of ...
in six extant
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 ...
. Although, superficially, they resemble other diving birds such as
loons and
coots, they are most closely related to
flamingo
Flamingos or flamingoes are a type of wading bird in the family Phoenicopteridae, which is the only extant family in the order Phoenicopteriformes. There are four flamingo species distributed throughout the Americas (including the Caribbean) ...
s, as supported by
morphological, molecular and
paleontological data. Many species are
monogamous and are known for their courtship displays, with the pair performing synchronized dances across the water's surface. The birds build floating vegetative nests where they lay several eggs. About a third of the world's grebes are listed at various levels of conservation concerns—the biggest threats including habitat loss, the introduction of invasive predatory fish and human
poaching
Poaching has been defined as the illegal hunting or capturing of wild animals, usually associated with land use rights.
Poaching was once performed by impoverished peasants for subsistence purposes and to supplement meager diets. It was set ag ...
. As such, three species have gone extinct.
Field characteristics
Grebes are small to medium-large in size, have lobed toes, and are excellent swimmers and divers. Although they can run for a short distance, they are prone to falling over, since they have their feet placed far back on the body. Grebes have narrow wings, and some species are reluctant to fly; indeed, two
South America
South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the souther ...
n species are completely flightless.
[ They respond to danger by diving rather than flying, and are in any case much less wary than ]duck
Duck is the common name for numerous species of waterfowl in the family Anatidae. Ducks are generally smaller and shorter-necked than swans and geese, which are members of the same family. Divided among several subfamilies, they are a fo ...
s. Extant species range in size from the least grebe, at 120 g (4.3 oz) and 23.5 cm (9.3 in), to the great grebe, at 1.7 kg (3.8 lbs) and 71 cm (28 in). Bills vary from short and thick to long and pointed depending on the diet. The feet are always large, with broad lobes on the toes and small webs connecting the front three toes. The hind toe also has a small lobe. Recent experimental work has shown that these lobes work like the hydrofoil blades of a propeller.
Grebes have unusual plumage
Plumage ( "feather") is a layer of feathers that covers a bird and the pattern, colour, and arrangement of those feathers. The pattern and colours of plumage differ between species and subspecies and may vary with age classes. Within species, ...
. It is dense and waterproof, and on the underside the feathers are at right angles to the skin, sticking straight out to begin with and curling at the tip. By pressing their feathers against the body, grebes can adjust their buoyancy
Buoyancy (), or upthrust, is an upward force exerted by a fluid that opposes the weight of a partially or fully immersed object. In a column of fluid, pressure increases with depth as a result of the weight of the overlying fluid. Thus the p ...
. Often, they swim low in the water with just the head and neck exposed. They swim by simultaneously spreading out the feet and bringing them inward, with the webbing expanded to produce the forward thrust in much the same way as frogs. In the nonbreeding season, grebes are plain-coloured in dark browns and whites. However, most have ornate and distinctive breeding plumages, often developing chestnut markings on the head area, and perform elaborate display rituals.[ The young, particularly those of the genus '' Podiceps'', are often striped and retain some of their juvenile plumage even after reaching full size. When preening, grebes eat their own feathers and feed them to their young. The function of this behaviour is uncertain, but it is believed to assist with pellet formation and to reduce their vulnerability to gastric ]parasite
Parasitism is a Symbiosis, close relationship between species, where one organism, the parasite, lives on or inside another organism, the Host (biology), host, causing it some harm, and is Adaptation, adapted structurally to this way of lif ...
s.
Systematics
The grebes are a radically distinct group of birds as regards their anatomy
Anatomy () is the branch of biology concerned with the study of the structure of organisms and their parts. Anatomy is a branch of natural science that deals with the structural organization of living things. It is an old science, having its ...
. Accordingly, they were at first believed to be related to the loons, which are also foot-propelled diving birds, and both families were once classified together under the order Colymbiformes. However, as early as the 1930s, this was determined to be an example of convergent evolution
Convergent evolution is the independent evolution of similar features in species of different periods or epochs in time. Convergent evolution creates analogous structures that have similar form or function but were not present in the last com ...
by the strong selective forces encountered by unrelated birds sharing the same lifestyle at different times and in different habitat. Grebes and loons are now separately classified orders of Podicipediformes and Gaviiformes, respectively. Recent molecular studies have suggested a relation with flamingo
Flamingos or flamingoes are a type of wading bird in the family Phoenicopteridae, which is the only extant family in the order Phoenicopteriformes. There are four flamingo species distributed throughout the Americas (including the Caribbean) ...
s while morphological evidence also strongly supports a relationship between flamingos and grebes. They hold at least eleven morphological traits in common, which are not found in other birds. Many of these characteristics have been previously identified in flamingos, but not in grebes. One clade of fossil stem-flamingos the palaelodids can be considered evolutionarily, and ecologically, intermediate between flamingos and grebes. For the grebe-flamingo clade, the taxon
In biology, a taxon ( back-formation from '' taxonomy''; plural taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular n ...
Mirandornithes
Mirandornithes () is a clade that consists of flamingos and grebes. Many scholars use the term Phoenicopterimorphae for the superorder containing flamingoes and grebes.
Determining the relationships of both groups has been problematic. Flamingos ...
("miraculous birds" due to their extreme divergence and apomorphies) has been proposed. Alternatively, they could be placed in one order, with Phoenocopteriformes taking priority.
Fossil grebes
The fossil record
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 preserved ...
of grebes is incomplete; there are no transitional forms between more conventional birds and the highly derived grebes known from fossils, or at least none that can be placed in the relationships of the group with any certainty. The enigmatic waterbird genus
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 n ...
''Juncitarsus
''Juncitarsus'' is an extinct genus of wading birds from the Eocene of the United States and Germany. Though previously considered a kind of prehistoric flamingo,Olson, S.L. And Feduccia, A. 1980. Relationship and evolution of flamingos (Ave ...
'', however, may be close to a common ancestor of flamingos and grebes.
The Early Cretaceous
The Early Cretaceous (geochronological name) or the Lower Cretaceous ( chronostratigraphic name), is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 145 Ma to 100.5 Ma.
Geology
Pr ...
( Berriasian, around 143 mya
Mya may refer to:
Brands and product names
* Mya (program), an intelligent personal assistant created by Motorola
* Mya (TV channel), an Italian Television channel
* Midwest Young Artists, a comprehensive youth music program
Codes
* Burmese ...
) genus ''Eurolimnornis
''Eurolimnornis'' is the name given to a monotypic genus of pterosaurs from the Early Cretaceous. The only known species ''E. corneti'' probably was originally identified as a primitive but essentially modern bird (or even as an early neognathe ...
'' from NW Romania
Romania ( ; ro, România ) is a country located at the crossroads of Central, Eastern, and Southeastern Europe. It borders Bulgaria to the south, Ukraine to the north, Hungary to the west, Serbia to the southwest, Moldova to the east, a ...
was initially believed to be a grebe. If it is indeed related to this lineage, it must represent a most basal
Basal or basilar is a term meaning ''base'', ''bottom'', or ''minimum''.
Science
* Basal (anatomy), an anatomical term of location for features associated with the base of an organism or structure
* Basal (medicine), a minimal level that is nec ...
form, as it almost certainly predates any grebe-flamingo split. On the other hand, the single bone fragment assigned to this taxon is not very diagnostic and may not be of a bird at all.
''Telmatornis
''Telmatornis'' is a valid prehistoric bird genus of unclear affiliations. It apparently lived in the Late Cretaceous; its remains were found in the early Maastrichtian (c.71-68 million years ago) Navesink Formation of New Jersey. A single ...
'' from the Navesink Formation
The Navesink Formation is a 66 to 70 mya greensand glauconitic marl and sand geological formation in New Jersey. It is known for its Cretaceous period fossil shell beds and dinosaur bones.
Description
The Navesink Formation, named after Nave ...
– also Late Cretaceous – is traditionally allied with the Charadriiformes
Charadriiformes (, from '' Charadrius'', the type genus of family Charadriidae) is a diverse order of small to medium-large birds. It includes about 390 species and has members in all parts of the world. Most charadriiform birds live near water ...
and/or Gruiformes. However, a cladistic
Cladistics (; ) is an approach to biological classification in which organisms are categorized in groups (" clades") based on hypotheses of most recent common ancestry. The evidence for hypothesized relationships is typically shared derived ch ...
analysis of the forelimb skeleton found it highly similar to the 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 ...
and unlike the painted buttonquail (now known to be a basal
Basal or basilar is a term meaning ''base'', ''bottom'', or ''minimum''.
Science
* Basal (anatomy), an anatomical term of location for features associated with the base of an organism or structure
* Basal (medicine), a minimal level that is nec ...
charadriiform lineage), the black-necked stilt
The black-necked stilt (''Himantopus mexicanus'') is a locally abundant shorebird of American wetlands and coastlines. It is found from the coastal areas of California through much of the interior western United States and along the Gulf of Mexic ...
(a more advanced charadriiform), or the limpkin (a member of the Grui suborder of Gruiformes), namely in that its dorsal condyle of the humerus
In human anatomy of the arm, the capitulum of the humerus is a smooth, rounded eminence on the lateral portion of the distal articular surface of the humerus. It articulates with the cupshaped depression on the head of the radius, and is limited ...
was not angled at 20°–30° away from long axis of the humerus
The humerus (; ) is a long bone in the arm that runs from the shoulder to the elbow. It connects the scapula and the two bones of the lower arm, the radius and ulna, and consists of three sections. The humeral upper extremity consists of a roun ...
. The analysis did not result in a phylogenetic
In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...
pattern but rather grouped some birds with similar wing shapes together while others stood separate. It is thus unknown whether this apparent similarity to grebes represents an evolutionary relationship, or whether ''Telmatornis'' simply had a wing similar to that of grebes and moved it like they do.
True grebes suddenly appear in the fossil record in the Late Oligocene
The Oligocene ( ) is a geologic epoch of the Paleogene Period and extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that define the epoch are well identified but ...
or Early Miocene
The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recent" ...
, around 23–25 mya
Mya may refer to:
Brands and product names
* Mya (program), an intelligent personal assistant created by Motorola
* Mya (TV channel), an Italian Television channel
* Midwest Young Artists, a comprehensive youth music program
Codes
* Burmese ...
. While there are a few prehistoric genera that are now completely extinct; '' Thiornis'' (Late Miocene –? Early Pliocene of Libros, Spain) and '' Pliolymbus'' (Late Pliocene of WC USA – Early? Pleistocene of Chapala, Mexico) date from a time when most if not all extant genera were already present.[ Because grebes are evolutionarily isolated and they only started to appear in the Northern Hemisphere fossil record in the Early Miocene, they are likely to have originated in the Southern Hemisphere.]
* Genus †'' Miobaptus'' Švec, 1982
** †'' Miobaptus huzhiricus'' Zelenkov, 2015
** †'' Miobaptus walteri'' Švec, 1982 (Švec, 1984) Mlíkovský, 2000">'Podiceps walteri'' (Švec, 1984) Mlíkovský, 2000* Genus †''Miodytes
''Miodytes'' is a fossil genus of grebe known from a nearly complete specimen from Valjevo Basin, western Serbia known from an almost complete right wing skeleton. It contains a single species, ''M. serbicus''.
History
The specimen was collect ...
'' Dimitreijevich, Gál & Kessler, 2002
** †'' Miodytes serbicus'' Dimitreijevich, Gál & Kessler, 2002
* Genus †'' Pliolymbus'' Murray, 1967 'Piliolymbus'' (sic)** †''Pliolymbus baryosteus
''Pliolymbus'' is a fossil genus of grebe known from the Late Pliocene to Early Pleistocene of United States and Mexico. It is known from a single species, ''P. baryosteus''.
History
The specimens were collected in the summer of 1950 from Kans ...
'' Murray, 1967
* Genus †'' Thiornis'' Navás, 1922
** †'' Thiornis sociata'' Navás, 1922 (Navás, 1922) Olson, 1995">'Podiceps sociatus'' (Navás, 1922) Olson, 1995
A few more recent grebe fossils could not be assigned to modern or prehistoric genera:
*Podicipedidae gen. et sp. indet. (San Diego Late Pliocene of California) – formerly included in ''Podiceps parvus''[
*Podicipedidae gen. et sp. indet. UMMP 49592, 52261, 51848, 52276, KUVP 4484 (Late Pliocene of WC USA)]
*Podicipedidae gen. et sp. indet. (Glenns Ferry Late Pliocene/Early Pleistocene of Idaho, USA)[
]
Phylogeny
To date there is no complete phylogeny of grebes based on molecular work. However there are comprehensive morphological work from Fjeldså (2004) and Ksepka et al. (2013) that has been done on the grebe genera.
Fjeldså (2004)
Ksepka et al. (2013)
Recent species listing
Compiled from the following websites: Extinct species assignment follows the Mikko's Phylogeny Archive and Paleofile.com websites. and subspecies names from ''English Names of Birds
English usually refers to:
* English language
* English people
English may also refer to:
Peoples, culture, and language
* ''English'', an adjective for something of, from, or related to England
** English national ide ...
''.
Natural history
Habitat, distribution and migration
Grebes are a nearly cosmopolitan clade of waterbirds, found on every continent except Antarctica
Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean, it contains the geographic South Pole. Antarctica is the fifth-largest co ...
. They are absent from the Arctic circle and arid environments. They have successfully colonized and radiated into islands such as Madagascar
Madagascar (; mg, Madagasikara, ), officially the Republic of Madagascar ( mg, Repoblikan'i Madagasikara, links=no, ; french: République de Madagascar), is an island country in the Indian Ocean, approximately off the coast of East Africa ...
and New Zealand
New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 List of islands of New Zealand, smaller islands. It is the ...
. Some species such as the eared grebe
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. There are currently three accepted subspecies, including the nominate subspe ...
(''Podiceps nigricollis'') and 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 ...
(''P. cristatus'') are found in multiple continents with regional subspecies or populations. A few species like the Junin grebe (''P. taczanowskii'') and the recently extinct Atitlan grebe (''Podilymbus gigas'') are lake endemics. During the warmer or breeding seasons, many species of grebes in the northern hemisphere reside in a variety of freshwater
Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. Although the term specifically excludes seawater and brackish water, it does in ...
habitats like lake
A lake is an area filled with water, localized in a basin, surrounded by land, and distinct from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, although, like the much lar ...
s and marsh
A marsh is a wetland that is dominated by herbaceous rather than woody plant species.Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p Marshes can often be found a ...
es. Once winter arrives many will migrate to marine environment
Marine habitats are habitats that support marine life. Marine life depends in some way on the saltwater that is in the sea (the term ''marine'' comes from the Latin ''mare'', meaning sea or ocean). A habitat is an ecological or environmen ...
s usually along the coastlines. The species is most prevalent in the New World
The term ''New World'' is often used to mean the majority of Earth's Western Hemisphere, specifically the Americas."America." ''The Oxford Companion to the English Language'' (). McArthur, Tom, ed., 1992. New York: Oxford University Press, p. ...
with almost half of the world's species living in this part of the world.
Feeding ecology
The feeding ecology of grebes is diverse within the group. Larger species such as those in the genus '' Aechmophorus'' have spear-like bills to catch mid-depth fish while smaller species such as those in the genera '' Tachybaptus'' and '' Podilymbus'' tend to be short and stout with a preference for catching small aquatic invertebrates. There are much more species of grebes that predate on aquatic invertebrates, with only a handful of large-bodied piscivores. The aforementioned ''Aechmophorus''is the most piscivorous of the grebes. Closely related species that overlap in their often avoid interspecific competition by having prey preferences and adaptations for it. In areas where there is just as a single species, they tend to have more generalized bill with more open preferences to different prey sources.
Breeding and reproduction
Grebes are perhaps best known for their elaborate courtship displays. Most species perform a duet together and many have their own synchronized rituals. Some like those species in the genus '' Podiceps'' do the iconic "penguin dance" where the male and female stand upright, breast posturing out and run along the water's surface. A similar ritual in other species is the "weed dance" in which both partners hold pieces of aquatic vegetation in their bills and positioned upright towards each other. Similarily there is the "weed rush" in which partners would swim towards each other, necks stretched out with weeds in their bill, and just before colliding do posture themselves upright and then swim in parallel. In the smaller and basal genera like ''Tachybaptus'' and ''Podilymbus'' there is some form of incorporation of aquatic vegetation in their courtship, but it is not as elaborate as the more derived and larger species. It has been hypothesized that such courtship displays between mates originated from intraspecific aggression that evolved in a way it strengthen pair bonds. Once these courtship rituals are completed, both partners would solicit copulation towards each other and would mount on these floating platforms of vegetation. Sometimes they become nests, although often they build a more well structured platform. Females lay two to seven eggs and incubation can last nearly a month. Chicks of the nest hatch asynchronously and once the whole nest has hatched, do the chicks begin to climb on one of their parent's backs. Both parents take care of rearing their young, and the duration of care is longer than those of waterfowl. This enables a greater success rate of survival for the chicks. One parent would dive while the other would watch the young on the surface.
Conservation
Thirty percent of the total extant species are considered to be threaten species by the IUCN. The handful of critically endangered and extinct species of grebe are those of lake endemics and nearly all of them are or were flightless. The extinct species consists of the Alaotra grebe (''Tachybaptus rufolavatus''), the Atitlán grebe, and the Colombian grebe (''Podiceps andinus''). These species went extinct due to anthropogenic changes, such as habitat loss, the introduction of invasive predatory fishes, and the usage of fishing nets that tangled birds in the lakes they once existed in. These are the same issues along with climate change that are happening to the Colombian grebe's closest relatives, the Junin grebe and hooded grebe (''Po. gallardoi'').
See also
*List of Podicipediformes by population
This is a list of Podicipediformes species by global population. While numbers are estimates, they have been made by the experts in their fields. For more information on how these estimates were ascertained, see Wikipedia's articles on populatio ...
References
Further reading
*Konter, André (2001): ''Grebes of our world: visiting all species on 5 continents''. Lynx Edicions, Barcelona.
* Ogilvie, Malcolm & Rose, Chris (2003): ''Grebes of the World''. Bruce Coleman Books, Uxbridge, England.
* Sibley, Charles Gald & Monroe, Burt L. Jr. (1990): ''Distribution and taxonomy of the birds of the world: A Study in Molecular Evolution''. Yale University Press, New Haven, CT.
External links
Grebe videos and photos
on the Internet Bird Collection
Tree of Life Grebes
*openclipart.org
Grebes clip-art
''Diving Birds of North America''
by Paul Johnsgard
Paul Austin Johnsgard (28 June 1931 – 28 May 2021) was an ornithologist, artist and emeritus professor at the University of Nebraska. His works include nearly fifty books including several monographs, principally about the waterfowl and crane ...
Grebes Walk on Water
Documentary produced by Oregon Field Guide
Grebe Vocalization - The Songs of The Grebes
*
{{Authority control
Podicipedidae
Podicipediformes
Diving animals
Extant Chattian first appearances
Taxa named by Charles Lucien Bonaparte