Editing Tree warbler (section)

== Taxonomy ==
All the tree warblers were formerly placed in the "[[Old World warbler]]" family Sylviidae but are now separated in the family [[Acrocephalidae]], along with the marsh warblers, ''[[Acrocephalus (bird)|Acrocephalus]]'', and some related species.

Considerable evidence, much of it summarised in Parkin et al. (2004),<ref>{{cite journal|last1=Parkin|first1= David T.|first2= Martin|last2= Collinson|first3=Andreas|last3= J. Helbig|first4= Alan G. |last4=Knox|authorlink5=George Sangster|last5=Sangster|first5=George|authorlink6=Lars Svensson (ornithologist)|first6=Lars|last6= Svensson|year=2004|url=http://www.britishbirds.co.uk/search?id=9067|title=Species limits in ''Acrocephalus'' and ''Hippolais'' warblers from the Western Palearctic|journal=[[British Birds (magazine)|British Birds]]|volume=97 |issue= 6| pages =276–299}}</ref> suggests that the genus ''Hippolais'' is [[paraphyletic]] with respect to ''Acrocephalus''. DNA studies, e.g. Leisler et al. (1997),<ref>{{cite journal|last=Leisler|first= B.|author2=Heidrich, P. |author3=Schulze-Hagen, K. M. |author4= Wink, M. |year=1997|doi=10.1007/BF01651381|title= Taxonomy and phylogeny of reed warblers (genus ''Acrocephalus'') based on mtDNA sequences and morphology|journal=[[J. Ornithol.]]|volume=138|pages=469–496|issue=4|bibcode= 1997JOrni.138..469L}}</ref> interpreted by [[George Sangster]] in 1997,<ref>{{cite journal|last=Sangster|first= George|authorlink=George Sangster|year=1997|title= Trends in Systematics – ''Acrocephalus'' and ''Hippolais'' relationships: shaking the tree |journal=[[Dutch Birding]] |volume= 19 |issue= 6 |pages =294–300}}</ref> indicated that the olivaceous and booted/Sykes's warbler grouping (the subgenus ''Iduna'') are more closely related to ''Acrocephalus'' species than they are to icterine and melodious warblers and as a result the Dutch Committee on Avian Systematics (CSNA) has moved these four species into ''Acrocephalus''.<ref>{{cite journal|last1=Sangster|first1= George|authorlink1=George Sangster|first2=Cornelius J. |last2=Hazevoet|authorlink2=Cornelis Hazevoet|first3= Arnoud B. |last3=van den Berg |first4= C. S.|last4= Roselaar |year=1998|title=Dutch avifaunal list: species concepts, taxonomic instability, and taxonomic changes in 1998 |journal=[[Dutch Birding]]|volume=20 |issue= 1| pages =22–32}}</ref> A subsequent review by the [[British Ornithologists' Union Records Committee]] retained the genus ''Hippolais'', for all eight species, but in agreement with Sangster, acknowledged that they fell into two groups.<ref>{{cite journal|first1=Alan G. |last1=Knox|first2= Martin|last2= Collinson|first3=Andreas J.|last3= Helbig|first4=David T. |last4=Parkin|authorlink5=George Sangster|first5=George|last5=Sangster|year=2002|title= Taxonomic recommendations for British birds |journal=[[Ibis (journal)|Ibis]]|volume= 144 |issue=4|pages= 707–710|doi=10.1046/j.1474-919X.2002.00110.x|doi-access=free}}</ref>

The retention of the ''Iduna'' grouping within ''Hippolais'' was done because it was felt that more evidence was needed for its placement, because of low bootstrap values,<ref>{{cite journal|last1=Helbig|first1= A. J.|last2=Seibold|first2= I.|year=1999|title= Molecular phylogeny of Palearctic-African ''Acrocephalus'' and ''Hippolais'' warblers (Aves: Sylviidae)|doi=10.1006/mpev.1998.0571 |journal=[[Mol. Phylogenet. Evol.]]|volume=11|pages=246–260|issue=2|pmid=10191069|bibcode= 1999MolPE..11..246H}}</ref> rather than because of a belief that the status quo was correct – no evidence was put forward to refute the DNA findings. Mark Constantine, in ''The Sound Approach to Birding'',<ref>{{cite book|last1=Constantine|first1=Mark|last2=The Sound Approach|year=2006|edition=1st.|title=The Sound Approach to birding: a guide to understanding bird sound|location=Dorset, England|publisher=The Sound Approach|isbn=90-810933-1-2|pages=142–148}}</ref> illustrated that there is extensive overlap in song types between species from the two genera, and that vocally, no characters existed which enabled species to be sorted into one genus or the other. [[Kenneth Williamson]]<ref>{{cite book|last=Williamson|first= K.|year=1968|title=Identification for ringers 1. The genera Cettia, Locustella, Acrocephalus and Hippolais}}</ref> and [[Hadoram Shirihai]],<ref>{{cite book|last1=Harris|first1= A.|authorlink2=H. Shirihai|last2=Shirihai|first2=H.|first3=D.|last3= Christie|title=The Macmillan birder's guide to European and Middle Eastern birds|title-link= The Macmillan birder's guide to European and Middle Eastern birds}}</ref> in discussing the identification of ''Hippolais'' and ''Acrocephalus'' warblers stressed the similarities between species in the two genera. Colin Bradshaw, in ''[[British Birds (magazine)|British Birds]]'', has written several articles on morphological similarity between cross-generic species-pairs e.g. eastern olivaceous and Blyth's reed warblers (Bradshaw 2000)<ref>{{cite journal|last=Bradshaw|first=Colin|year=2000|title=Separating ''Acrocephalus'' and ''Hippolais'' warblers|journal=[[British Birds (magazine)|British Birds]]|volume=93 |issue=6 |page= 277}}</ref> and paddyfield and booted warblers (e.g. Bradshaw & Steele 1995,<ref>{{cite journal|last1=Bradshaw|first1= Colin |first2= Jimmy|last2= Steele |year=1995|url=http://www.britishbirds.co.uk/search?id=7885 |title=Mystery photographs 195|journal=[[British Birds (magazine)|British Birds]]|volume=88|issue=11|pages= 561–564}}</ref> Bradshaw & Steele 1997,<ref>{{cite journal|last1=Bradshaw|first1= Colin |first2= Jimmy|last2= Steele |year=1997|title=Mystery warblers in Tselinograd|journal=[[British Birds (magazine)|British Birds]]|volume=90|issue=4 |pages= 155–158}}</ref> the latter a response to [[Lars Svensson (ornithologist)|Lars Svensson]]'s comments<ref>{{cite journal|authorlink=Lars Svensson (ornithologist)|last=Svensson, Lars|year=1997|title=Mystery warblers in Tselinograd |journal=[[British Birds (magazine)|British Birds]]|volume=90|issue=4 |pages= 152–154}}</ref> on Bradshaw & Steele 1995).

The species are:{{citation needed|date=April 2013}}<!-- which classification? -->

Genus ''[[Iduna (bird)|Iduna]]''
* [[Thick-billed warbler]], ''Iduna aedon''
* [[Booted warbler]], ''Iduna caligata''
* [[Sykes's warbler]], ''Iduna rama''
* [[Western olivaceous warbler]] (or isabelline warbler),<ref>The name isabelline warbler was first used in volume 11 of the Handbook of the Birds of the World.</ref> ''Iduna opaca''
* [[Eastern olivaceous warbler]], ''Iduna pallida''
* [[Mountain yellow warbler]], ''Iduna similis''
* [[African yellow warbler]], ''Iduna natalensis''

Genus ''[[Hippolais]]''

* [[Upcher's warbler]], ''Hippolais languida''
* [[Olive-tree warbler]], ''Hippolais olivetorum''
* [[Melodious warbler]], ''Hippolais polyglotta''
* [[Icterine warbler]], ''Hippolais icterina''

Genus ''Calamonastides''
* [[Papyrus yellow warbler]], ''Calamonastides gracilirostris''