Grey Wagtail
Encyclopedia
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. The species is widely distributed, with several populations breeding in Europe and Asia and migrating to tropical regions in Asia and Africa. They are usually seen on open marshy ground or meadows where they walk solitarily or in pairs along the ground, capturing insects that are disturbed. Like other wagtails, they frequently wag their tail and fly low with undulations and they have a sharp call that is often given in flight.
This slim wagtail has a narrow white supercilium and a broken eye ring. The upperparts are grey and the yellow vent contrasting with whitish underparts makes it distinctive. The breeding male has a black throat that is edged by whitish moustachial stripes. They forage singly or in pairs on meadows or on shallow water marshes. They also use rocks in water and will often perch on trees. They have a clear sharp call note and the song consists of trills.
They sometimes occur on the islands to the West of Alaska but have been known to occur further south in California as a vagrant.
in his 1771 Ornithologia Britannica.
The relationships of this species are not well resolved; it belongs to the non-Africa
n clade
of wagtails, these are confusing in their external morphology
, and mtDNA cytochrome b
and NADH dehydrogenase
subunit
2 sequence
data are not able to robustly resolve their relationships. While the present species is probably most closely related to Citrine Wagtail
s and some Blue-headed Wagtail
s, the exact nature of this relationship is unclear.
The breeding season is April to July and the nest is placed near fast running streams or rivers on an embankment between stones and roots. The male in display, makes short flights up into the air and descends slowly with fluttering flight accompanied by a rapid series of chipping high notes. In Europe the nests are often made in holes in manmade structures. The clutch consists of 3-6 speckled eggs and multiple broods may be raised with declining numbers in the clutch in subsequent broods. The usual clutch size is five in Ireland and the breeding success is about 80% with predation of eggs or chicks being the main cause of breeding failure. The Canary Islands population typically have smaller clutches and the breeding season is not as short and well marked as in populations at higher latitudes. The incubation period is about two weeks with chicks fledging within a fortnight. They live for a maximum of 8 years in the wild.
In some parts of the its range the White-throated Dipper
nests in the same habitats as the Grey Wagtail and there are some records of interspecific feeding
of dipper chicks by nesting wagtails.
These birds feed on a variety of aquatic invertebrates including adult flies, mayflies, beetles, crustacea and molluscs. They often forage along roadsides in winter, flushing with a sharp chi-cheep call and flying up further along the road but after some distance turning back to return to the original location.
In winter, they roost in small groups. Wintering birds have been known to return to the same sites, sometimes a small urban garden, each year.
Adults often have parasitic ticks, Ixodes ricinus
, which can harbour Borrelia
and thus can potentially disperse Lyme disease over a wide region. Coccidia such as Isospora
sp. are known in this species. The Common Cuckoo
is sometimes a brood parasite of this species. and Kestrel
s may sometimes prey on them.
Wagtail
The wagtails form the passerine bird genus Motacilla. They are small birds with long tails which they wag frequently. Motacilla, the root of the family and genus name, means moving tail...
family, Motacillidae
Motacillidae
The Motacillidae are a family of small passerine birds with medium to long tails. There are around 65 species in 6 genera and they include the wagtails, longclaws and pipits. The longclaws are entirely restricted to the Afrotropics, and the wagtails are predominately found in Europe, Africa and...
. The species looks similar to the Yellow Wagtail but has the yellow on its underside restricted to the throat and vent
Cloaca
In zoological anatomy, a cloaca is the posterior opening that serves as the only such opening for the intestinal, reproductive, and urinary tracts of certain animal species...
. Breeding males have a black throat. The species is widely distributed, with several populations breeding in Europe and Asia and migrating to tropical regions in Asia and Africa. They are usually seen on open marshy ground or meadows where they walk solitarily or in pairs along the ground, capturing insects that are disturbed. Like other wagtails, they frequently wag their tail and fly low with undulations and they have a sharp call that is often given in flight.
Description
Distribution
The bird is widely distributed across the Palearctic region with several well marked populations. The nominate form (includes caspica of Iran, Turkey and the Caucasus) is from western Europe including the British Isles, Scandinavia and Mediterranean region. Race melanope, which is not well separated from the nominate subspecies, is described as the population breeding in eastern Europe and central Asia mainly along the mountain chains of the Urals, Tien Shan and along the Himalayas. They winter in Africa and Asia. Race robusta breeds along the northeastern parts of Asia in Siberia extending to Korea and Japan. These winter in Southeast Asia. Island forms include patriciae of the Azores, schmitzi of Madeira and canariensis of the Canary Islands.They sometimes occur on the islands to the West of Alaska but have been known to occur further south in California as a vagrant.
Taxonomy and systematics
This species was first described by Marmaduke TunstallMarmaduke Tunstall
Marmaduke Tunstall was an English ornithologist and collector. He was the author of Ornithologica Britannica , probably the first British work to use binomial nomenclature....
in his 1771 Ornithologia Britannica.
The relationships of this species are not well resolved; it belongs to the non-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...
n 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...
of wagtails, these are confusing in their external morphology
Morphology (biology)
In biology, morphology is a branch of bioscience dealing with the study of the form and structure of organisms and their specific structural features....
, and 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 are not able to robustly resolve their relationships. While the present species is probably most closely related to 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...
s and some 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...
s, the exact nature of this relationship is unclear.
Behaviour and ecology
In some parts of the its range the White-throated Dipper
White-throated Dipper
The White-throated Dipper , also known as the European Dipper or just Dipper is an aquatic passerine bird found in Europe, Middle East, Central Asia and the Indian Subcontinent. The species is divided into several subspecies, based primarily on colour differences, particularly of the pectoral band...
nests in the same habitats as the Grey Wagtail and there are some records of interspecific feeding
Interspecific feeding
Interspecific feeding refers to behaviour reported in wild animals, particularly birds where adults of one species feed the young of another species. This usually excludes the case of birds feeding brood parasites. The behaviour has been of theoretical interest since it appears to be provide little...
of dipper chicks by nesting wagtails.
These birds feed on a variety of aquatic invertebrates including adult flies, mayflies, beetles, crustacea and molluscs. They often forage along roadsides in winter, flushing with a sharp chi-cheep call and flying up further along the road but after some distance turning back to return to the original location.
In winter, they roost in small groups. Wintering birds have been known to return to the same sites, sometimes a small urban garden, each year.
Adults often have parasitic ticks, Ixodes ricinus
Ixodes ricinus
Ixodes ricinus, the castor bean tick, is a chiefly European species of hard-bodied tick. It may reach a length of when engorged with a blood meal, and can transmit both bacterial and viral pathogens such as the causative agents of Lyme disease and tick-borne encephalitis.-Description:In common...
, which can harbour Borrelia
Borrelia
Borrelia is a genus of bacteria of the spirochete phylum. It causes borreliosis, a zoonotic, vector-borne disease transmitted primarily by ticks and some by lice, depending on the species...
and thus can potentially disperse Lyme disease over a wide region. Coccidia such as Isospora
Isospora
Isospora is a genus of internal parasites classified under Coccidia.It is responsible for the condition isosporiasis.At least 248 species have been described in this genus, but most of them are little studied and it is doubtful whether all should be recognized as distinct species...
sp. are known in this species. The Common Cuckoo
Common Cuckoo
The Common Cuckoo is a member of the cuckoo order of birds, Cuculiformes, which includes the roadrunners, the anis and the coucals....
is sometimes a brood parasite of this species. and Kestrel
Kestrel
The name kestrel, is given to several different members of the falcon genus, Falco. Kestrels are most easily distinguished by their typical hunting behaviour which is to hover at a height of around over open country and swoop down on prey, usually small mammals, lizards or large insects...
s may sometimes prey on them.