在鶺鴒屬Motacilla中,白鶺鴒的最近遺傳親屬似乎是其他黑白鶺鴒,如日本鶺鴒(Motacilla grandis)和印度鶺鴒(Motacilla madaraspatensis),以及可能還包括湄公鶺鴒(Motacilla samveasnae),其系統發生學地位仍不明確,牠們似乎形成了一個超種。然而,mtDNA細胞色素b與NADH脫氫酶亞基2的序列數據顯示,白鶺鴒本身是多系群或並系群(即該物種本身不是一個單一的連貫群體)。[7] 其他使用mtDNA的系統發生學研究仍表明該物種內部有顯著的基因流動,這使得Motacilla alba仍被視為單一物種。[8] 一項研究表明可能只有兩個群體:alba群,包括M. a. alba、M. a. yarrellii、M. a. baicalensis、M. a. ocularis、M. a. lugens及M. a. subpersonata;以及alboides群,包括M. a. alboides、M. a. leucopsis及M. a. personata。[9]
還有多種其他亞種,其中一些可能是由於部分地理隔離而產生,例如英國和愛爾蘭的常住型,斑鶺鴒M. a. yarrellii,該亞種目前也在鄰近的歐洲大陸區域繁殖。斑鶺鴒因自然學家威廉·耶雷爾命名,其雄性以黑色代替指名亞種的淺灰色,雌性和幼鳥則是深灰色,但行為與指名亞種無異。其他亞種(其中一些的有效性仍有疑問)在翅膀、背部和頭部的顏色或其他特徵上有所不同。一些亞種在繁殖季節會表現出兩性異形。在印度或東南亞的越冬地可能出現多達六個亞種,牠們在這裡很難區分。[11][12][13][14] 使用mtDNA的系統發生學研究表明,一些形態特徵可能已多次進化,包括背部和下巴的顏色。繁殖期的M. a. yarrellii與指名種非常相似,除了黑色的背部外,喜馬拉雅的M. a. alboides與中亞的M. a. personata僅在其黑色背部上有所區別。M. a. personata已在西喜馬拉雅山脈的克什米爾錫達爾谷記錄到繁殖。[15] 還有觀察指出,背部和下巴在初基換羽時會變色;所有黑喉亞種在冬季會發展出白色下巴和喉部,一些黑背鳥在冬季會變成灰背。[8][11]
^Linnaeus, Carl. Systema naturae per regna tria naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Tomus I. Editio decima, reformata.. Holmiae. (Laurentii Salvii). 1758: 185 (拉丁语). M. pectore nigro, recticibus duabus lateralibus dimidiato oblique albis.
^ 8.08.1Pavlova, A.; Zink, R. M.; Rohwer, S.; Koblik, E. A.; Red'kin, Y. A.; Fadeev, I. V. & Nesterov, E. V. Mitochondrial DNA and plumage evolution in the white wagtail Motacilla alba. Journal of Avian Biology. 2005, 36 (4): 322–336. doi:10.1111/j.0908-8857.2005.03373.x.
^Odeen, A.; Alstrom, P. Evolution of secondary traits in wagtails (genus Motacilla). Effects of post-glacial range expansion and population bottlenecks on species richness (学位论文). Uppsala University. 2001.
^Wasser, D. E.; Sherman, P. W. Avian longevities and their interpretation under evolutionary theories of senescence. Journal of Zoology. 2010, 280 (2): 103. doi:10.1111/j.1469-7998.2009.00671.x.
^Nakamura, Kazue. Historical change of the geographical distribution of two closely related species of the genus Motacilla in the Japanese Archipelago: a preliminary note. Bulletin of the Kanagawa Prefecture Museum of Natural Science. 1985, 16(日语).
^Badyaev, Alexander V.; Gibson, Daniel D.; Kessel, Brina; Pyle, Peter; Patten, Michael A. White wagtail. Birds of the World (Cornell University). 4 May 2017. doi:10.2173/bow.whiwag.01.
^British Ornithologists' Union Records Committee; British Birds Rarities Committee. Changes to Category A of the British List. BOU News. British Ornithologists' Union. 22 July 2009 [22 July 2009].
^Rowlands, Adam. Proposed criteria for BBRC assessment of claims of 'Amur Wagtail'. British Birds. May 2010, 103: 268–275.
^ 24.024.1Snow, David; Perrins, Christopher M. (编). The Birds of the Western Palearctic concise edition (2 volumes). Oxford: Oxford University Press. 1998: 1103–1106. ISBN 978-0-19-854099-1.
^Arlott, Norman). Birds of the Palearctic: Passerines (Collins Field Guide). Harper Collins. 2007: 30–31. ISBN 978-0-00-714705-2.
^Sibley, David. The North American Bird Guide. Pica Press. 2000. ISBN 978-1873403983.
^Randler, Christoph. Is tail wagging in white wagtails, Motacilla alba, an honest signal of vigilance?. Animal Behaviour. 2006, 71 (5): 1089–1093. S2CID 53189368. doi:10.1016/j.anbehav.2005.07.026.
^Davies, N.B. Food, Flocking and Territorial Behaviour of the Pied Wagtail (Motacilla alba yarrellii Gould) in Winter. The Journal of Animal Ecology. 1976, 45 (1): 235–253. Bibcode:1976JAnEc..45..235D. JSTOR 3777. doi:10.2307/3777.