Wagtail
Overview
 
The wagtails form the passerine
Passerine
A passerine is a bird of the order Passeriformes, which includes more than half of all bird species. Sometimes known as perching birds or, less accurately, as songbirds, the passerines form one of the most diverse terrestrial vertebrate orders: with over 5,000 identified species, it has roughly...

 bird
Bird
Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...

 genus Motacilla. They are small birds with long tails which they wag frequently. Motacilla, the root of the family
Family
In human context, a family is a group of people affiliated by consanguinity, affinity, or co-residence. In most societies it is the principal institution for the socialization of children...

 and genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 name, means moving tail. The Forest Wagtail
Forest Wagtail
The Forest Wagtail is a medium-sized passerine bird in the wagtail family Motacillidae. It has a distinctive plumage that sets it apart from other wagtails and has the habit of wagging its tail sideways unlike the usual up and down movements of the other wagtail species. It is the only wagtail...

 belongs to the monotypic
Monotypic
In biology, a monotypic taxon is a taxonomic group with only one biological type. The term's usage differs slightly between botany and zoology. The term monotypic has a separate use in conservation biology, monotypic habitat, regarding species habitat conversion eliminating biodiversity and...

 genus Dendronanthus which is closely related to Motacilla and sometimes included herein.

The Willie Wagtail
Willie Wagtail
The Willie Wagtail is a passerine bird native to Australia, New Guinea, the Solomon Islands, the Bismarck Archipelago, and eastern Indonesia. It is a common and familiar bird throughout much of its range, living in most habitats apart from thick forest...

 (Rhipidura leucophrys) of Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

 is an unrelated bird similar in colouration and shape to the Japanese Wagtail
Japanese Wagtail
The Japanese Wagtail, Motacilla grandis, is a species of bird in the pipit and wagtail family Motacillidae. It breeds in Japan and Korea. Vagrant birds have been recorded in Taiwan, eastern China and far-eastern Russia. In Japan, it is generally common from Kyushu northward, but uncommon in...

.
Encyclopedia
The wagtails form the passerine
Passerine
A passerine is a bird of the order Passeriformes, which includes more than half of all bird species. Sometimes known as perching birds or, less accurately, as songbirds, the passerines form one of the most diverse terrestrial vertebrate orders: with over 5,000 identified species, it has roughly...

 bird
Bird
Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...

 genus Motacilla. They are small birds with long tails which they wag frequently. Motacilla, the root of the family
Family
In human context, a family is a group of people affiliated by consanguinity, affinity, or co-residence. In most societies it is the principal institution for the socialization of children...

 and genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 name, means moving tail. The Forest Wagtail
Forest Wagtail
The Forest Wagtail is a medium-sized passerine bird in the wagtail family Motacillidae. It has a distinctive plumage that sets it apart from other wagtails and has the habit of wagging its tail sideways unlike the usual up and down movements of the other wagtail species. It is the only wagtail...

 belongs to the monotypic
Monotypic
In biology, a monotypic taxon is a taxonomic group with only one biological type. The term's usage differs slightly between botany and zoology. The term monotypic has a separate use in conservation biology, monotypic habitat, regarding species habitat conversion eliminating biodiversity and...

 genus Dendronanthus which is closely related to Motacilla and sometimes included herein.

The Willie Wagtail
Willie Wagtail
The Willie Wagtail is a passerine bird native to Australia, New Guinea, the Solomon Islands, the Bismarck Archipelago, and eastern Indonesia. It is a common and familiar bird throughout much of its range, living in most habitats apart from thick forest...

 (Rhipidura leucophrys) of Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

 is an unrelated bird similar in colouration and shape to the Japanese Wagtail
Japanese Wagtail
The Japanese Wagtail, Motacilla grandis, is a species of bird in the pipit and wagtail family Motacillidae. It breeds in Japan and Korea. Vagrant birds have been recorded in Taiwan, eastern China and far-eastern Russia. In Japan, it is generally common from Kyushu northward, but uncommon in...

. It belongs to the fantail flycatcher
Fantail
Fantails are small insectivorous birds of southern Asia and Australasia belonging to the genus Rhipidura in the family Rhipiduridae...

s.

Characteristics

Wagtails are slender, often colourful, ground-feeding insectivore
Insectivore
An insectivore is a type of carnivore with a diet that consists chiefly of insects and similar small creatures. An alternate term is entomophage, which also refers to the human practice of eating insects....

s of open country in the Old World
Old World
The Old World consists of those parts of the world known to classical antiquity and the European Middle Ages. It is used in the context of, and contrast with, the "New World" ....

. They are ground nesters, laying up to six speckled egg
Egg (biology)
An egg is an organic vessel in which an embryo first begins to develop. In most birds, reptiles, insects, molluscs, fish, and monotremes, an egg is the zygote, resulting from fertilization of the ovum, which is expelled from the body and permitted to develop outside the body until the developing...

s at a time. Among their most conspicuous behaviours is a near constant tail wagging, a trait that has given the birds their common name. In spite of the ubiquity of the behaviour and observations of it, the reasons for it are poorly understood. It has been suggested that it may flush up prey, or that it may signal submissiveness to other wagtails. Recent studies have suggested instead that it is a signal of vigilance that may aid to deter potential predators.

Systematics

At first glance, the wagtails appear to be divided into a yellow-bellied group and a white-bellied one, or one where the upper head is black and another where it is usually gray, but may be olive, yellow, or other colors. However, these are not evolution
Evolution
Evolution is any change across successive generations in the heritable characteristics of biological populations. Evolutionary processes give rise to diversity at every level of biological organisation, including species, individual organisms and molecules such as DNA and proteins.Life on Earth...

ary lineages; change of belly color and increase of melanin
Melanin
Melanin is a pigment that is ubiquitous in nature, being found in most organisms . In animals melanin pigments are derivatives of the amino acid tyrosine. The most common form of biological melanin is eumelanin, a brown-black polymer of dihydroxyindole carboxylic acids, and their reduced forms...

 have occurred independently several times in the wagtails, and the color patterns which actually indicate relationships are more subtle.

mtDNA cytochrome b
Cytochrome b
Cytochrome b/b6 is the main subunit of transmembrane cytochrome bc1 and b6f complexes. In addition, it commonly refers to a region of mtDNA used for population genetics and phylogenetics.- Function :...

 and NADH dehydrogenase
NADH dehydrogenase
NADH dehydrogenase is an enzyme located in the inner mitochondrial membrane that catalyzes the transfer of electrons from NADH to coenzyme Q...

 subunit
Protein subunit
In structural biology, a protein subunit or subunit protein is a single protein molecule that assembles with other protein molecules to form a protein complex: a multimeric or oligomeric protein. Many naturally occurring proteins and enzymes are multimeric...

 2 sequence
DNA sequence
The sequence or primary structure of a nucleic acid is the composition of atoms that make up the nucleic acid and the chemical bonds that bond those atoms. Because nucleic acids, such as DNA and RNA, are unbranched polymers, this specification is equivalent to specifying the sequence of...

 data (Voelker, 2002) is of limited use: the suspicion that there is a superspecies
Superspecies
A superspecies is a group of at least two more or less distinctive species with approximately parapatric distributions. Not all species complexes, whether cryptices or ring species are superspecies, and vice versa, but many are...

 of probably 3 white-bellied, black-throated wagtails is confirmed. Also, there is another superspecies in sub-Saharan Africa
Sub-Saharan Africa
Sub-Saharan Africa as a geographical term refers to the area of the African continent which lies south of the Sahara. A political definition of Sub-Saharan Africa, instead, covers all African countries which are fully or partially located south of the Sahara...

, three white-throated species with a black breast-band. The remaining five species are highly variable morphologically and their relationships with each other and with the two clade
Clade
A clade is a group consisting of a species and all its descendants. In the terms of biological systematics, a clade is a single "branch" on the "tree of life". The idea that such a "natural group" of organisms should be grouped together and given a taxonomic name is central to biological...

s have not yet been satisfactorily explained.

The origin of the genus appears to be in the general area of Eastern Siberia
Siberia
Siberia is an extensive region constituting almost all of Northern Asia. Comprising the central and eastern portion of the Russian Federation, it was part of the Soviet Union from its beginning, as its predecessor states, the Tsardom of Russia and the Russian Empire, conquered it during the 16th...

/Mongolia. Wagtails spread rapidly across Eurasia and dispersed to Africa
Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...

 in the Zanclean
Zanclean
The Zanclean is the lowest stage or earliest age on the geologic time scale of the Pliocene. It spans the time between 5.332 and 3.6 Ma ± 0.005 Ma . It is preceded by the Messinian age of the Miocene epoch, and followed by the Piacenzian age....

 (Early Pliocene
Pliocene
The Pliocene Epoch is the period in the geologic timescale that extends from 5.332 million to 2.588 million years before present. It is the second and youngest epoch of the Neogene Period in the Cenozoic Era. The Pliocene follows the Miocene Epoch and is followed by the Pleistocene Epoch...

)
where the sub-Saharan lineage was later isolated. The African Pied Wagtail
African Pied Wagtail
The African Pied Wagtail is a species of bird in the Motacillidae family.-Habitat and distribution:It is found in Angola, Benin, Botswana, Burkina Faso, Burundi, Cameroon, Central African Republic, Chad, Republic of the Congo, Democratic Republic of the Congo, Ivory Coast, Egypt, Equatorial...

 (and possibly the Mekong Wagtail
Mekong Wagtail
The Mekong Wagtail is a species of bird in the Motacillidae family.It is found in Cambodia, Laos, and Thailand.Its natural habitats are subtropical or tropical moist shrubland and rivers....

) diverged prior to the massive radiation of the white-bellied black-throated and most yellow-bellied forms, all of which took place during the late Piacenzian
Piacenzian
The Piacenzian is in the international geologic timescale the upper stage or latest age of the Pliocene. It spans the time between 3.6 ± 0.005 Ma and 2.588 ± 0.005 Ma...

 (early Late Pliocene), approximately around 3 mya.

Three species are poly- or paraphyletic in the present taxonomical
Taxonomy
Taxonomy is the science of identifying and naming species, and arranging them into a classification. The field of taxonomy, sometimes referred to as "biological taxonomy", revolves around the description and use of taxonomic units, known as taxa...

 arrangement and either subspecies
Subspecies
Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...

 need to be reassigned and/or species split up. The Blue-headed Wagtail
Blue-headed Wagtail
The Yellow Wagtail, Motacilla flava, is a small passerine in the wagtail family Motacillidae, which also includes the pipits and longclaws.This species breeds in much of temperate Europe and Asia and has a foothold in North America in Alaska...

 (AKA Yellow Wagtail and many other names), especially, has always been a taxonomical nightmare with over a dozen currently accepted subspecies and many more invalid ones. The two remaining "monochrome
Monochrome
Monochrome describes paintings, drawings, design, or photographs in one color or shades of one color. A monochromatic object or image has colors in shades of limited colors or hues. Images using only shades of grey are called grayscale or black-and-white...

" species, Mekong
Mekong Wagtail
The Mekong Wagtail is a species of bird in the Motacillidae family.It is found in Cambodia, Laos, and Thailand.Its natural habitats are subtropical or tropical moist shrubland and rivers....

 and African Pied Wagtail
African Pied Wagtail
The African Pied Wagtail is a species of bird in the Motacillidae family.-Habitat and distribution:It is found in Angola, Benin, Botswana, Burkina Faso, Burundi, Cameroon, Central African Republic, Chad, Republic of the Congo, Democratic Republic of the Congo, Ivory Coast, Egypt, Equatorial...

 may be closely related, or a most striking example of convergent evolution
Convergent evolution
Convergent evolution describes the acquisition of the same biological trait in unrelated lineages.The wing is a classic example of convergent evolution in action. Although their last common ancestor did not have wings, both birds and bats do, and are capable of powered flight. The wings are...

.

Prehistoric wagtails known from fossils are Motacilla humata and Motacilla major.

See the species accounts for more on individual species' relationships.

Species in taxonomic order

  • White Wagtail
    White Wagtail
    "Pied Wagtail" redirects here. For the related African bird, see African Pied Wagtail.The White Wagtail is a small passerine bird in the wagtail family Motacillidae, which also includes the pipits and longclaws. This species breeds in much of Europe and Asia and parts of north Africa...

     Motacilla alba - polyphyletic or paraphyletic
    • Pied Wagtail Motacilla alba yarrellii
    • Black-backed Wagtail Motacilla (alba) lugens
  • Japanese Wagtail
    Japanese Wagtail
    The Japanese Wagtail, Motacilla grandis, is a species of bird in the pipit and wagtail family Motacillidae. It breeds in Japan and Korea. Vagrant birds have been recorded in Taiwan, eastern China and far-eastern Russia. In Japan, it is generally common from Kyushu northward, but uncommon in...

     Motacilla grandis
  • White-browed Wagtail
    White-browed Wagtail
    The White-browed Wagtail or Large Pied Wagtail is a medium-sized bird and is the largest member of the wagtail family. They are conspicuously patterned with black above and white below, a prominent white brow, shoulder stripe and outer tail feathers...

     Motacilla maderaspatensis
  • Mekong Wagtail
    Mekong Wagtail
    The Mekong Wagtail is a species of bird in the Motacillidae family.It is found in Cambodia, Laos, and Thailand.Its natural habitats are subtropical or tropical moist shrubland and rivers....

     Motacilla samveasnae
  • African Pied Wagtail
    African Pied Wagtail
    The African Pied Wagtail is a species of bird in the Motacillidae family.-Habitat and distribution:It is found in Angola, Benin, Botswana, Burkina Faso, Burundi, Cameroon, Central African Republic, Chad, Republic of the Congo, Democratic Republic of the Congo, Ivory Coast, Egypt, Equatorial...

     Motacilla aguimp
  • Citrine Wagtail
    Citrine Wagtail
    The Citrine Wagtail or Yellow-headed Wagtail is a small songbird in the family Motacillidae. The term citrine refers to its yellowish colouration. Its systematics, phylogeny and taxonomy are subject of considerable debate in the early 21st century. This is because this bird forms a cryptic...

     Motacilla citreola - possibly paraphyletic
  • Yellow Wagtail Motacilla flava
    • Yellow Wagtail Motacilla flava flava - paraphyletic
  • Grey Wagtail
    Grey Wagtail
    The Grey Wagtail is a small member of the wagtail family, Motacillidae. The species looks similar to the Yellow Wagtail but has the yellow on its underside restricted to the throat and vent. Breeding males have a black throat...

     Motacilla cinerea
  • Cape Wagtail
    Cape Wagtail
    The Cape Wagtail is a small passerine bird in the family Motacillidae, which includes the wagtails, pipits and longclaws....

     Motacilla capensis
  • Madagascar Wagtail
    Madagascar Wagtail
    The Madagascar Wagtail is a species of bird in the Motacillidae family.It is endemic to Madagascar.Its natural habitats are subtropical or tropical seasonally wet or flooded lowland grassland and rivers.-References:...

     Motacilla flaviventris
  • Mountain Wagtail
    Mountain Wagtail
    The Mountain Wagtail , also known as the Long-tailed Wagtail, is a species of bird in the Motacillidae family....

    Motacilla clara


The Mekong Wagtail was described as new to science only in 2001.

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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