Editing Algerian nuthatch (section)

=== Phylogeny ===
[[File:Sitta krueperi - Christoph Moning - 2 (cropped).jpeg|thumb|alt=A grey bird with white face and orange body at the branch of tree |The male [[Krüper's nuthatch]] has the front half of the crown black, like the Algerian nuthatch; it is the closest relative of the latter species.]]
The Algerian nuthatch is placed in the [[subgenus]] ''Micrositta'', described by the Russian ornithologist [[Sergei Buturlin]] in 1916,<ref name="Matthysen 2010">{{cite book | last=Matthysen | first=Erik | title=The Nuthatches | publisher=A & C Black | publication-place=London | year=2010 | isbn=978-1-4081-2870-1 | oclc=727646681 | page=}}</ref> and has no [[subspecies]].<ref>{{cite web | title=Nuthatches, Wallcreeper, treecreepers, mockingbirds, starlings, oxpeckers – IOC World Bird List | website=IOC World Bird List – Version 11.2 | url=https://www.worldbirdnames.org/bow/nuthatch/  |archive-url=https://ghostarchive.org/archive/20220130/https://www.worldbirdnames.org/bow/nuthatch/  |archive-date=2022-01-30 |url-status=live| access-date=24 January 2022}}{{cbignore}}</ref> American ornithologist [[Charles Vaurie]] had grouped in 1957 the Corsican nuthatch, the [[red-breasted nuthatch]] (''Sitta canadensis'') and the [[Chinese nuthatch]] (''Sitta villosa''), which he considered to be very similar, in the "''Sitta canadensis''" group.<ref>{{cite journal|journal= American Museum Novitates|last= Vaurie|first= Charles|issue= 1854|year=1957|pages=1–26|title= Systematic notes on Palearctic birds. No. 29, The subfamilies Tichodromadinae and Sittinae|hdl= 2246/3596|url=https://digitallibrary.amnh.org/handle/2246/3596|issn=1937-352X|oclc=47720325}}</ref> In his 1976 description of the Algerian nuthatch, Vielliard devotes a portion of his paper to the possible relationships of the different species and their [[evolutionary]] history. He suggests that Vaurie stopped at a "superficial [[Morphology (biology)|morphological]] similarity" to bring the Corsican nuthatch closer to the red-breasted nuthatch, and that the Corsican species should rather form with Krüper's nuthatch a group known as the "Mesogean nuthatches", "where ''Sitta ledanti'' providentially fits in".<ref name="Jacques Vielliard 4"/> He considers it "tempting" to identify the [[fossil]] species ''Sitta senogalliensis'' (whose membership to the genus ''Sitta'' is discussed) described from the Upper [[Miocene]] in [[Italy]] as the ancestor of the Mesogean nuthatch group.<ref name="Jacques Vielliard 4"/>

In 1998, Eric Pasquet studied the [[cytochrome b]] gene in the [[mitochondrial DNA]] of about ten nuthatch species, including the various species of the ''Sitta canadensis'' group,<ref name="Packert2014 molecular">{{cite journal | title=Phylogeny of the nuthatches of the Sitta canadensis group and its evolutionary and biogeographic implications| first=Eric | last=Pasquet | name-list-style=amp | journal=The Ibis | volume=140 | issue=1 | pages= 150–156|date= January 1998| doi=10.1111/j.1474-919X.1998.tb04553.x }}</ref> which he defined as comprising six species, corresponding to those reported in the subgenus, ''Micrositta'':<ref name="Matthysen 2010"/> ''S. canadensis'', ''S. villosa'', ''S. whiteheadi'', ''S. yunnanensis'', ''S. krueperi'' and ''S. ledanti''. Pasquet concluded that the Corsican nuthatch is [[phylogeny|phylogenetically]] related to the Chinese nuthatch and the red-breasted nuthatch, these three species forming the [[sister group]] of a [[clade]] including Krüper's nuthatch and the Algerian nuthatch. The first three species would even be close enough to constitute subspecies, rejecting the "Mesogean" theory of Vielliard and thus confirming the conclusions of Charles Vaurie.<ref name="Packert2014 molecular"/> For the sake of [[taxonomic]] stability, however, all retain their full species status.<ref>{{cite book |last1=Thibault |first1= Jean-Claude|last2=Seguin |first2= Jean-François|last3=Norris |first3= Ken|url=https://archive.wikiwix.com/cache/index2.php?url=http%3A%2F%2Fwww.developpement-durable.gouv.fr%2FIMG%2Fpdf%2FPNA_Sittelle_corse.pdf%2Findex.html#federation=archive.wikiwix.com|title= Taxonomic status and biogeographic origin |location=Regional Natural Park of Corsica|date=2000|page=52 }}</ref> In 2014, Eric Pasquet and colleagues published a phylogeny based on [[Nuclear DNA|nuclear]] and mitochondrial DNA of 21 nuthatch species and confirmed the relationships of the 1998 study within the "''Sitta canadensis'' group", adding the [[Yunnan nuthatch]], which was found to be the most [[Basal (phylogenetics)|basal]] of the species.<ref name="Pasquet2014">{{cite journal|doi=10.1007/s10336-014-1063-7|url=https://link.springer.com/article/10.1007/s10336-014-1063-7|title=Evolution within the nuthatches (Sittidae: Aves, Passeriformes): molecular phylogeny, biogeography, and ecological perspectives|journal=[[Journal of Ornithology]]|date=April 2014|author1=Eric Pasquet |author2=Keith F. Barker |author3=Jochen Martens |author4=Annie Tillier |author5=Corinne Cruaud |author6=Alice Cibois|volume=155|issue=3|pages=755–765|bibcode=2014JOrni.155..755P |s2cid=17637707}}</ref>

The conclusions of these studies are in agreement with the morphology of the species, the red-breasted nuthatch, Corsican nuthatch and Chinese nuthatch sharing as a derived character the entirely black crown only present in males, a unique trait among the nuthatches and related families. The second clade, which includes Krüper's and Algerian nuthatches, have the front of the crown black in males, with this [[sexually dimorphic]] trait absent in juveniles.<ref name="Packert2014 molecular"/>

The simplified [[cladogram]] below is based on the [[phylogenetic analysis]] of Packert and colleagues (2014):<ref name="Pasquet2014"/>

{|
|-
| style="vertical-align:top;"|{{Clade|style=font-size:90%;line-height:100% <!--the line-height reduces line separation -->
|1={{clade
   |1=[[Yunnan nuthatch]] (''S. yunnanensis'')
   |2={{clade
      |1={{clade
         |1=Algerian nuthatch ('''''S. ledanti''''')
         |2=[[Krüper's nuthatch]] (''S. krueperi'')
         }}
      |2={{clade
         |1={{clade
            |1=[[Corsican nuthatch]] (''S. whiteheadi'')
            |2=[[Chinese nuthatch]] (''S. villosa'')
            }}
         |2=[[Red-breasted nuthatch]] (''S. canadensis'')
         }}
       }}
   }}
}}
|}