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Grebes
Clark's Grebe, Aechmophorus clarkii
Clark's Grebe, Aechmophorus clarkii
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Podicipediformes
Fürbringer, 1888
Family: Podicipedidae
Bonaparte, 1831
Genera

Grebes are members of the Podicipediformes order, a widely distributed order of freshwater diving birds, some of which visit the sea when migrating and in winter. The Clark's Grebe ( Aechmophorus clarkii) is a North American Species in the Grebe family Chordates ( Phylum Chordata) are a group of Animals that includes the Vertebrates together with several closely related Invertebrates Birds ( class Aves) are bipedal endothermic ( Warm-blooded) Vertebrate animals that lay eggs. Max Fürbringer ( January 30, 1846 – March 6, 1920) was a German anatomist. Charles Lucien (Carlo Jules Laurent Bonaparte 2nd Prince of Canino and Musignano ( May 24, 1803 &ndash July 29, 1857) was a French Aechmophorus is a Genus of Birds in the Grebe family It has two living representatives breeding in western North America. Podiceps is a genus of Birds in the Grebe family It has representatives breeding in Europe, Asia, North and Podilymbus is a genus of Birds in the Podicipedidae family Species Atitlán Grebe, Podilymbus gigas Poliocephalus is a small genus of Birds in the Grebe family Its two members are found in Australia and New Zealand. Rollandia is a small genus of Birds in the Grebe family Its two members are found in South America. Tachybaptus is a genus of small members of the Grebe family birds It has representatives over much of the world including the tropics This article is about the taxonomic rank for the sequence of species in a taxonomic list see Taxonomic order In scientific classification used Birds ( class Aves) are bipedal endothermic ( Warm-blooded) Vertebrate animals that lay eggs. Bird migration refers to the regular seasonal journeys undertaken by many species of Birds Bird movements include those made in response to changes in food availability This order contains only a single family, the Podicipedidae, containing 22 species in 6 extant genera. In Biological classification, family ( Latin In Biology, a species is one of the basic units of Biological classification and a Taxonomic rank. A genus (plural genera from Γένος Latin genus "descent family type gender" is a low-level Taxonomic

Contents

Description

Grebes are small to medium-large in size, have lobed toes, and are excellent swimmers and divers. However, they have their feet placed far back on the body, can run for a short distance, but often fall over.

Grebes have narrow wings, and some species are reluctant to fly; indeed, two South American species are completely flightless. South America is a Continent of the Americas, situated entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a They respond to danger by diving rather than flying, and are in any case much less wary than ducks. For duck as a food see Duck (food; for other meanings see Duck (disambiguation. Extant species range in size from the Least Grebe, at 120 grams (4. The Least Grebe ( Tachybaptus dominicus) an aquatic Bird, is the smallest member of the Grebe family 3 oz) and 23. 5 cm (9. 3 inches), to the Great Grebe, at 1. The Great Grebe ( Podiceps major) is the largest species of Grebe on earth 7 kg (3. 8 lbs) and 71 cm (28 inches).

However, the North American and Eurasian species are all, of necessity, migratory over much or all of their ranges, and those species that winter at sea are also seen regularly in flight. For the superstate in George Orwell 's novel see Nations of Nineteen Eighty-Four. Even the small freshwater Pied-billed Grebe of North America has occurred as a transatlantic vagrant to Europe on more than 30 occasions. The Pied-billed Grebe ( Podilymbus podiceps) is a Species of the Grebe family of water birds

Bills vary from short and thick to long and pointed; 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. A hydrofoil is a Boat with wing-like foils mounted on struts below the hull. Curiously, the same mechanism apparently evolved independently in the extinct Cretaceous-age Hesperornithiformes, which are totally unrelated birds. eVolution is the third Album by eLDee, it was due to be released in 2008 The Cretaceous (kriːˈteɪʃəs, usually abbreviated 'K' for its German translation "Kreide" is a geologic period and system, reaching from the end of Hesperornithes is an extinct and highly specialized Clade of Cretaceous toothed Birds Hesperornithine birds apparently limited to former aquatic habitats

Grebes have unusual plumage. Feathers are one of the epidermal growths that form the distinctive outer covering or Plumage, on Birds They are considered the most complex integumentary structures 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. In Physics, buoyancy ( BrE IPA: /ˈbɔɪənsi/ is the upward Force on an object produced by the surrounding liquid or gas in which it is Often, they swim low in the water with just the head and neck exposed.

In the non-breeding 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 Podiceps genus, are often striped and retain some of their juvenile plumage even after reaching full size. Podiceps is a genus of Birds in the Grebe family It has representatives breeding in Europe, Asia, North and

When preening, grebes eat their own feathers, and feed them to their young. Personal grooming (also called titivating) is the art of cleaning grooming and maintaining parts of the body The function of this behaviour is uncertain but it is believed to assist with pellet formation and to reduce their vulnerability to gastric parasites. Parasitism is a type of symbiotic relationship between Organisms of different Species.

Taxonomy

The grebes are a radically distinct group of birds as regards their anatomy. Anatomy (from the Greek anatomia, from ana separate apart from and temnein, to cut up cut open is a branch of Biology that is the consideration Accordingly, they were at first believed to be related to the loons, which are also foot-propelled diving birds. The loons (eg North America or divers (eg UK/Ireland are a group of aquatic birds found in many parts of North America and northern Eurasia However, as recently as the 1930s (Stolpe 1935), this was determined to be an example of convergent evolution by the strong selective forces encountered by unrelated birds sharing the same lifestyle at different times and in different habitat. Convergent evolution describes the acquisition of the same biological trait in unrelated lineages In the context of Evolution, certain traits or Alleles of a Species may be subject to selection

The cladistics vs. Cladistics is the hierarchical classification of Species based on evolutionary ancestry phenetics debate of the mid-20th century revived scientific interest in generalizing comparisons. Phenetics should not be confused with Phonetics, the study of speech sounds despite the similarity in pronunciation The twentieth century of the Common Era began on As a consequence, the discredited grebe-loon link was discussed again. This even went as far as proposing monophyly for grebes, loons, and the toothed Hesperornithiformes (Cracraft, 1982). A clade is a taxonomic group comprising a single Common ancestor and all the descendants of that ancestor Hesperornithes is an extinct and highly specialized Clade of Cretaceous toothed Birds Hesperornithine birds apparently limited to former aquatic habitats In retrospect, the scientific value of the debate lies more in providing examples that a cladistic methodology is not incompatible with an overall phenetical scientific doctrine, and that thus, simply because some study "uses cladistics", it does not guarantee superior results. Methodology (also called manner) is defined as "the analysis of the principles of methods rules and postulates employed by a discipline" Doctrine (Latin doctrina) is a codification of beliefs or "a body of teachings quot or "instructions" taught principles or positions as the

Molecular studies such as DNA-DNA hybridization (Sibley & Ahlquist, 1990) and sequence analyses fail to resolve the relationships of grebes properly due to insufficient resolution in the former and long-branch attraction in the latter. DNA-DNA hybridization generally refers to a Molecular biology technique that measures the degree of genetic similarity between pools of DNA sequences A DNA sequence or genetic sequence is a succession of letters representing the Primary structure of a real or hypothetical DNA Molecule Long branch attraction (LBA is a phenomenon in Phylogenetic analyses (most commonly those employing Maximum parsimony) when rapidly evolving lineages are inferred Still - actually because of this - they do confirm that these birds form a fairly ancient evolutionary lineage (or possibly one that was subject to selective pressures down to the molecular level even), and they support the non-relatedness of loons and grebes.

Currently, the available evidence is being reassessed. Combining data from the different analyses seems to point at flamingos being the closest relatives of the grebes, a suggestion that has been proposed every now and then in the past—mainly because both groups are aquatic birds of very obscure relationships—but generally ignored. Flamingos or flamingoes ( are gregarious Wading birds in the Genus Phoenicopterus and family Indeed, careful analyses of morphological characters (i. e. , excluding known homoplasies) and more comprehensive molecular data suggest that this relationship is the most promising hypothesis to date. Convergent evolution describes the acquisition of the same biological trait in unrelated lineages In addition, it has been shown that the Anaticola bird lice shared by flamingos and waterfowl, which were at one time used to support a close relationship between the latter two (which is now deemed utterly incorrect), are actually closely related to the grebes' Aquanirmus lice and almost certainly switched hosts from flamingos to waterfowl, not the other way around as it was usually assumed (Johnson et al. Bird louse refers to any Chewing louse ( Paraphyletic suborder Mallophaga which parasitizes Birds Recent reclassification has found that bird See also UK Wildfowl and Wetlands Trust USA Ducks Unlimited 2006).

Genera and species

Fossil grebes

The fossil record 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. Tachybaptus is a genus of small members of the Grebe family birds It has representatives over much of the world including the tropics The Little Grebe ( Tachybaptus ruficollis, formerly known as Dabchick) is 23 to 29 cm in length The Australasian Grebe, Tachybaptus novaehollandiae is a tiny Waterbird common on fresh water lakes and rivers in greater Australia, New Zealand The Madagascar Grebe Tachybaptus pelzelnii is a Grebe found only in western and central Madagascar. The Alaotra Grebe ( Tachybaptus rufolavatus) also known as Delacour's Little Grebe or Rusty Grebe, is or was a Grebe found only on In Biology and Ecology, extinction is the cessation of existence of a Species or group of taxa. The 1980s was the decade spanning from January 1 1980 to December 31 1989. The Least Grebe ( Tachybaptus dominicus) an aquatic Bird, is the smallest member of the Grebe family Podilymbus is a genus of Birds in the Podicipedidae family Species Atitlán Grebe, Podilymbus gigas The Pied-billed Grebe ( Podilymbus podiceps) is a Species of the Grebe family of water birds The Atitlán Grebe ( Podilymbus gigas) also known as Giant Grebe, Giant Pied-billed Grebe, or Poc, is an extinct water bird a relative Year 1989 ( MCMLXXXIX) was a Common year starting on Sunday (link displays 1989 Gregorian calendar) Rollandia is a small genus of Birds in the Grebe family Its two members are found in South America. UserPolbot. -->The White-tufted Grebe ( Rollandia rolland) is a species of Grebe in the Podicipedidae "Centropelma" redirects here This was also also the initial preoccupied name of the Spider genus Nicodamus. Poliocephalus is a small genus of Birds in the Grebe family Its two members are found in Australia and New Zealand. The Hoary-headed Grebe, Poliocephalus poliocephalus, is a member of the Grebe family found in Australia and since 1975 New Zealand, where The New Zealand Dabchick, Poliocephalus rufopectus, or Weweia, is a member of the Grebe family endemic to New Zealand. Podiceps is a genus of Birds in the Grebe family It has representatives breeding in Europe, Asia, North and The Red-necked Grebe, Podiceps grisegena, is a migratory aquatic bird that is found in the temperate regions of the northern hemisphere The Great Crested Grebe, Podiceps cristatus is a member of the Grebe family of water birds The Slavonian Grebe, Podiceps auritus, is a member of the Grebe family of water Birds It is known in North America as the Horned Grebe The Black-necked Grebe, Podiceps nigricollis, known in North America as the Eared Grebe, is a member of the Grebe family of water birds The Colombian Grebe ( Podiceps andinus) was a Grebe (aquatic bird found in the Bogotá wetlands in the Eastern Andes of Colombia. Also 1977 (album by Ash. Year 1977 ( MCMLXXVII) was a Common year starting on Saturday (link displays The Great Grebe ( Podiceps major) is the largest species of Grebe on earth UserPolbot. -->The Silvery Grebe ( Podiceps occipitalis) is a species of Grebe in the Podicipedidae The Junin Flightless Grebe Podiceps taczanowskii, also known as the Puna Grebe and the Junín Grebe, is a Grebe found only on Lake The Hooded Grebe ( Podiceps gallardoi) is a medium-sized Grebe found in the southern region of South America. Aechmophorus is a Genus of Birds in the Grebe family It has two living representatives breeding in western North America. The Western Grebe, ( Aechmophorus occidentalis)is a Species in the Grebe family of water birds Folk names include "dabchick" The Clark's Grebe ( Aechmophorus clarkii) is a North American Species in the Grebe family FOSSIL is a standard protocol for allowing serial communication for Telecommunications programs under the DOS Operating system. The enigmatic waterbird genus Juncitarsus, however, may be close to a common ancestor of flamingos and grebes. A genus (plural genera from Γένος Latin genus "descent family type gender" is a low-level Taxonomic

The Late Cretaceous (Berriasian, around 143 mya) genus Eurolimnornis from NW Romania was initially believed to be a grebe. Late Cretaceous (100mya - 65mya refers to the second half of the Cretaceous Period, named after the famous white Chalk cliffs of southern England In the Geologic timescale, Berriasian is a stage of the Early Cretaceous epoch, and the first of the entire Cretaceous period In Astronomy, Geology, and Paleontology, mya or " mya " is an abbreviation for "million years ago". Eurolimnornis is the name given to a Monotypic genus of fossil Bird from the Early Cretaceous. Romania ( dated: Rumania, Roumania If it is indeed related to this lineage, it must represent a most basal form, as it almost certainly predates any grebe-flamingo split. In Phylogenetics, a basal Clade is the earliest clade to branch in a larger clade it appears at the base of a cladogram On the other hand, the single bone fragment assigned to this taxon is not very diagnositc and may not be of a bird at all (Benton et al. , 1997).

Telmatornis from the Navesink Formation - also Late Cretaceous - is traditionally allied with the Charadriiformes and/or Gruiformes. Telmatornis is a prehistoric Bird Genus of unclear affiliations Charadriiformes is a diverse order of small to medium-large Birds It includes about 350 Species and has members in all parts of the world The diverse order Gruiformes contains a considerable number of living and extinct Bird families with on first sight little in common . However, a cladistic analysis of the forelimb skeleton (Varricchio 2002) found it highly similar to the Great Crested Grebe and unlike the Painted Buttonquail (now known to be a basal charadriiform lineage), the Black-necked Stilt (a more advanced charadriiform), or the Limpkin (a member of the Grui suborder of Gruiformes), namely in that its dorsal condyle of the humerus was not angled at 20°–30° away from long axis of the humerus. Cladistics is the hierarchical classification of Species based on evolutionary ancestry The Great Crested Grebe, Podiceps cristatus is a member of the Grebe family of water birds The Painted Buttonquail ( Turnix varia) is a Buttonquail, one of a small family of Birds which resemble but are unrelated to the true Quails In Phylogenetics, a basal Clade is the earliest clade to branch in a larger clade it appears at the base of a cladogram The Black-necked Stilt is a locally abundant Shorebird of American wetlands and coastlines The Limpkin (common names carrao, courlan, crying bird) Aramus guarauna, is a bird that looks like a large rail, but is skeletally This article is about the taxonomic rank for the sequence of species in a taxonomic list see Taxonomic order In scientific classification used In human anatomy of the arm the lateral portion of the articular surface of the Humerus consists of a smooth rounded eminence named the capitulum of the humerus. The humerus is a Long bone in the Arm or Forelimb that runs from the Shoulder to the Elbow. The analysis did not result in a phylogenetic 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 or Early Miocene, around 23-25 mya. The Oligocene is a geologic epoch of the Paleogene period and extends from about 33 The Miocene is a geological epoch of the Neogene period and extends from about 23 In Astronomy, Geology, and Paleontology, mya or " mya " is an abbreviation for "million years ago". 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. Only the Early Miocene Miobaptus from Czechoslovakia might be somewhat closer to the ancestral grebes, but more probably belongs to an extinct lineage. Czechoslovakia may also refer to what is now the Czech Republic and Slovakia. Indeed, Miobaptus is rivalled or even exceeded in age by a species of the modern genus Podiceps. Podiceps is a genus of Birds in the Grebe family It has representatives breeding in Europe, Asia, North and

A few more recent grebe fossils could not be assigned to modern or prehistoric genera as of now:

References

External links

Dictionary

grebe

-noun

  1. One of several swimming birds or divers, of the genus Colymbus (formerly Podiceps), and allied genera, found in the northern parts of America, Europe, and Asia. They have strong, sharp bills, and lobate toes.
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