{{short description|Species of bird}} {{about|the New World warbler|the Old World warbler|zitting cisticola}} {{speciesbox | image = Fan-tailed Warbler - Chiapas - Mexico S4E7230 (22445769633).jpg | status = LC | status_system = IUCN3.1 | status_ref = <ref name="iucn status 11 November 2021">{{cite iucn |author=BirdLife International |date=2020 |title=''Basileuterus lachrymosus'' |volume=2020 |article-number=e.T22721955A137221917 |doi=10.2305/IUCN.UK.2020-3.RLTS.T22721955A137221917.en |access-date=11 November 2021}}</ref> | genus = Basileuterus | species = lachrymosus | authority = Bonaparte, 1850 | synonyms = ''Euthlypis lachrymosa'' | range_map = Euthlypis lachrymosa map.svg | range_map_caption = <div style="text-align: left">{{legend|#FFFF00|Breeding range}}<br/>{{legend|#008000|Breeding and wintering range}}</div> }}

The '''fan-tailed warbler''' ('''''Basileuterus lachrymosus''''') is a New World warbler in the genus ''Basileuterus'' that lives along the Pacific slope from northern Mexico to Nicaragua. Vagrant records exist for Arizona, New Mexico and Texas. It is yellow on its throat and underparts with a tawny wash on its chest. The head is gray with a black-framed yellow crown and white around the eyes. The undertail coverlets are white. It is 5.8-6.3 in (14.5–16&nbsp;cm) long and has a pleasant, upslurred song. Fan-tailed warblers live in and at the edge of evergreen and semideciduous forest, especially near ravines. They eat insects, and are seen hopping around on either the forest floor or close to it. They are found alone or in pairs.

Fan-tailed warblers are known to engage in commensal feeding, wherein prey that has been roused or disturbed by the foraging or hunting of another animal is opportunistically captured. They have been observed following and foraging for prey near army ants, other passerines, and nine-banded armadillos.<ref>{{cite journal|last=Schaefer|first=Richard R.|author2=Jesse F. Fagan|title=Commensal foraging by a fan-tailed warbler (Euthlypis lachrymosa) with a nine-banded armadillo (Dasypus nocemcinctus) in southwestern Mexico|journal=The Southwestern Naturalist|date=December 2006|volume=51 | issue = 4|pages=560–61|url=https://www.srs.fs.usda.gov/pubs/ja/ja_schaefer009.pdf|doi=10.1894/0038-4909(2006)51[560:cfbafw]2.0.co;2}}</ref>

The fan-tailed warbler was formerly placed in the monotypic genus '''''Euthlypis''''' due to its unique morphology,<ref>{{Cite book | last=Curson | first=Jon | date=1994 | title=New World Warblers | location=London | publisher=Christopher Helm | isbn=978-0-7136-3932-2 | page=205 | url=https://archive.org/details/newworldwarblers0000curs/page/205/mode/1up | url-access=registration }}</ref> but its nest, eggs, voice, and juvenile plumage are consistent with ''Basileuterus''. A molecular phylogenetic study published in 2010 found that the fan-tailed warbler was basal to the other species in the genus ''Basileuterus''.<ref>{{Cite journal | last1=Lovette | first1=I.J. | last2=Pérez-Emán | first2=J.L. | last3=Sullivan | first3=J.P. | last4=Banks | first4=R. C. | last5=Fiorentino | first5=I. | last6=Córdoba-Córdoba | first6=S. | last7=Echeverry-Galvis | first7=M.A. | last8=Barker | first8=F.K. | last9=Burns | first9=K.J. | last10=Klicka| first10=J. | last11=Lanyon | first11=S.M. | last12=Bermingham | first12=E. | year=2010 | title=A comprehensive multilocus phylogeny for the wood-warblers and a revised classification of the Parulidae (Aves) | journal=Molecular Phylogenetics and Evolution | volume=57 | issue=2 | pages=753–770 | doi=10.1016/j.ympev.2010.07.018 }}</ref><!-- ref supports last sentence only--> In contrast, a 2024 molecular phylogenetic study found that the fan-tailed warbler was sister to a clade containing the genera ''Myioborus'', ''Cardellina'', and the remaining ''Basileuterus'' species.<ref>{{Cite journal | last1=Zhao | first1=M. | last2=Oswald | first2=J.A. | last3=Allen | first3=J.M. | last4=Owens | first4=H.L. | last5=Hosner | first5=P.A. | last6=Guralnick | first6=R.P. | last7=Braun | first7=E.L. | last8=Kimball | first8=R.T. | date=2024 | title=A phylogenomic tree of wood-warblers (Aves: Parulidae): Dealing with good, bad, and ugly samples | journal=Molecular Phylogenetics and Evolution | article-number=108235 | doi=10.1016/j.ympev.2024.108235}}</ref>

==References == {{Reflist}} * BirdLife International (2007) Species factsheet: Euthlypis lachrymosa. Downloaded from https://web.archive.org/web/20210828092113/https://www.birdlife.org/ on 8/8/2007 *Howell, Steven N. G. & Webb, Sophie (1995): ''A Guide to the Birds of Mexico and Northern Central America''. Oxford University Press, Oxford & New York. <small>{{ISBN|0-19-854012-4}}</small> *''A Guide to the Birds of Panama Second Edition'' by Ridgely and Gwynne {{ISBN|0-691-02512-6}} {{Taxonbar|from=Q27075999}}

fan-tailed warbler Category:Meso-American montane bird species fan-tailed warbler fan-tailed warbler