Editing Wagtail (section)

==Taxonomy==
[[File:Trjasoguzka.JPG|right|thumb|Wagtail]]
[[File:Motacilla alba yarrellii MWNH 2226.JPG|thumb|Egg, Collection [[Museum Wiesbaden, Germany|Museum Wiesbaden]], Germany]]
The genus ''Motacilla'' was described by the Swedish naturalist [[Carl Linnaeus]] in 1758 in the [[10th edition of Systema Naturae|tenth edition]] of his ''[[Systema Naturae]]''.<ref>{{cite book | last=Linnaeus | first=Carl | author-link=Carl Linnaeus | year=1758 | title= Systema Naturae per regna tria naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis | volume=1| edition=10th | page=184 | publisher=Holmiae:Laurentii Salvii  | language=la | url= https://biodiversitylibrary.org/page/727091 }}</ref>  The [[type species]] is the [[white wagtail]].<ref>{{ cite book | editor1-last=Mayr | editor1-first=Ernst | editor1-link=Ernst Mayr | editor2-last=Greenway | editor2-first=James C. Jr | year=1960 | title=Check-list of Birds of the World | volume=9 | publisher=Museum of Comparative Zoology  | place=Cambridge, Massachusetts  | page=130 | url=https://biodiversitylibrary.org/page/14480805 }}</ref> ''Motacilla'' is the [[Latin]] name for the pied wagtail; although actually a diminutive of ''motare'', "to move about", from medieval times it led to the misunderstanding of ''cilla'' as "tail".<ref name =job>{{cite book | last=Jobling | first=James A. | year= 2010| title=The Helm Dictionary of Scientific Bird Names | url=https://archive.org/details/Helm_Dictionary_of_Scientific_Bird_Names_by_James_A._Jobling | publisher=Christopher Helm | location=London | isbn=978-1-4081-2501-4 | page=[https://archive.org/details/Helm_Dictionary_of_Scientific_Bird_Names_by_James_A._Jobling/page/n261 261]}}</ref>

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 grey, but may be olive, yellow, or other colours. However, these are not [[evolution]]ary lineages; change of belly colour and increase of [[melanin]] have occurred independently several times in the wagtails, and the colour patterns which actually indicate relationships are more subtle.

[[mtDNA]] [[cytochrome b|cytochrome ''b'']] and [[NADH dehydrogenase]] [[Protein subunit|subunit]] 2 [[DNA sequence|sequence]] data (Voelker, 2002) is of limited use: the suspicion that there is a [[superspecies]] of probably three white-bellied, black-throated wagtails is confirmed. Also, there is another superspecies in [[sub-Saharan Africa]], 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]]s have not yet been satisfactorily explained.

The origin of the genus appears to be in the general area of Eastern [[Siberia]]/Mongolia. Wagtails spread rapidly across Eurasia and dispersed to [[Africa]] in the [[Zanclean]] (Early [[Pliocene]])<ref>
The date of 4.5 [[mya (unit)|mya]] in Voelker (2002) is dubious as it does not rely upon hard data but is merely an estimate based on average values now known to be often wrong.</ref>
where the sub-Saharan lineage was later isolated. The [[African pied wagtail]] (and possibly the [[Mekong wagtail]]) 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]] (early Late Pliocene), c. 3 mya.

Three species are poly- or paraphyletic in the present [[Taxonomy (biology)|taxonomical]] arrangement, and either [[subspecies]] need to be reassigned and/or species split up. The [[western yellow wagtail]] (AKA blue-headed wagtail, yellow wagtail, and many other names) especially, has always been a taxonomical nightmare, with ten currently accepted subspecies and many more invalid ones. The two remaining "[[monochrome]]" species, [[Mekong wagtail|Mekong]] and [[African pied wagtail]] may be closely related, or a most striking example of [[convergent evolution]].<ref name="Duckworth">{{cite journal |last1=Duckworth |first1=J. W. |last2=Alstrom|first2=Per|last3=Davidson|first3=P.|last4=Evans|first4=T. D.|last5=Poole|first5=C. M.|last6=Setha|first6=Tan|last7=Timmins|first7=R. J. |title=A new species of wagtail from the lower Mekong basin |journal=Bulletin of the British Ornithologists' Club |date=2001 |volume=121 |pages=152–182 |url=https://www.biodiversitylibrary.org/page/40086417 |access-date=2024-08-21}}</ref>

Prehistoric wagtails known from [[fossils]] are ''Motacilla humata'' and ''Motacilla major''.