Systematics

The Siberian Nuthatch was first described in 1907, under its current name Sitta arctica, by the Russian ornithologist Sergei Buturlin based on a specimen from Verhoyansk, Yakut, Russia (19 Buturlin, S. A. (1907). Neue Ost-Asiatische Formen. Volumen 15. Ornithologische Monatsberichte. 1907:79-80. Close ). In 1928, Otto Kleinschmidt lumped the Siberian Nuthatch with the Eurasian Nuthatch (Sitta europaea), with most authorities continuing to treat the two taxa as conspecifics (e.g., 7 Harrap, S., and D. Quinn (1996). Tits, Nuthatches & Treecreepers. Christopher Helm, London, UK. Close , 20 Clements, J. F., T. S. Schulenberg, M. J. Iliff, D. Roberson, T. A. Fredericks, B. L. Sullivan, and C. L. Wood. 2017. The eBird/Clements checklist of birds of the world: v2017 Close ).

That said, Eck suggested full-species status for the Siberian Nuthatch based on differences in morphology and behavior as long ago as 1984 (2 Eck, S. (1984). Katalog der ornithologischen Sammlung Dr. Udo Bährmanns (3. Fortsetzung). Zoologische Abhandlungen, Mu­seum für Tierkunde Dresden 39:71–98. Close , 4 Eck, S. (1996). Die Paläarktischen Vögel — Geospezies und Biospezies. Zoologische Abhandlung 49(Supplement). 103 pp. Close ). His diagnosis was later supported by biometric analyses and the demonstration of very limited hybridization at contact zones between the two nuthatches (21 Red’kin, Y. A,. and M. V. Konovalova (2006). Systematic notes on Asian birds. 63. The eastern Asiatic races of Sitta europaea Linnaeus, 1758. Zool. Meded. Leiden 80(5):241–261. Close ) plus distinct differences found in their mtDNA (22 Zink, R. M., S. V. Drovetski, and S. Rohwer (2006). Selective neutrality of mitochondrial ND2 sequences, phylogeography and species limits in Sitta europaea. Molecular Phylogenetics and Evolution 40:679–686. Close , 23 Hung, C.-M., S. V. Drovetski, and R. M. Zink (2012). Multilocus coalescence analyses support a mtDNA-based phylogeographic history for a widespread Palearctic passerine bird, Sitta europaea. Evolution 66(9):2850–2864. Close ). This led to the Siberian Nuthatch's return to full species status by various authorities during 2012–2020 (24 Sangster, G., J. M. Collinson, P.-A. Crochet, A. G. Knox, D. T. Parkin, and S. C. Votier (2012). Taxonomic recommendations for British birds: Eighth report. Ibis 154(4):874–883. Close , 25 Dickinson, E. C., and L. Christidis, Editors (2014). The Howard and Moore Complete Checklist of the Birds of the World. Volume 2. 4th edition. Aves Press, Eastbourne, UK. Close , 26 Gill, F., D. Donsker, and P. Rasmussen, Editors (2020). IOC World Bird List v10.1. Close ). Indeed, more recent findings using mitochondrial and nuclear DNA indicate that the Siberian Nuthatch is only distantly related to the monophyletic assemblage consisting of the Eurasian Nuthatch, Kashmir Nuthatch (Sitta cashmirensis) , Chestnut-vented Nuthatch (Sitta nagaensis) , White-tailed Nuthatch (Sitta himalayensis) , White-browed Nuthatch (Sitta victoriae) , and Indian Nuthatch (Sitta castanea) , from which it likely diverged in the late Miocene, 7.1–13.1 million years ago (27 Chen, Y.-H., M. Nazarizadeh, F.-M. Lei, X.-J. Yang, C.-T. Yao, F. Dong, L. Dong, F.-S. Zou, S. V. Drovetski, Y. Liu, C.-C. Huang, and C.-M. Hung (2019). The niches of nuthatches affect their lineage evolution differently across latitude. Molecular Ecology 28:803–817. Close , 28 Packert, M., M. Bader-Blukott, B. Künzelmann, Y.-H. Sun, Y.-C. Hsu, C. Kehlmaier, F. Albrecht, J. C. Illera, and J. Martens (2020). A revised phylogeny of nuthatches (Aves, Passeriformes, Sitta) reveals insight in intra- and interspecific diversification patterns in the Palearctic. Vertebrate Zoology 70:241–262. Close ).

This divergence occurred during the Tortonian Stage, when the first cold taiga forests emerged at high latitudes in the Palearctic (29 Finlayson, C. (2011). Avian Survivors: The History and Biogeog­raphy of Palearctic Birds. T. & A. D. Poyser, London, UK. Close , 30 Pound, M. J., A. M. Haywood, U. Salzmann, and J. B. Riding (2012). Global vegetation dynamics and latitudinal temperature gradients during the Mid to Late Miocene (15.97 – 5.33 Ma). Earth­ Science Reviews 112:1–22. Close ). Climate-vegetation modeling indicates that the far northeastern Palearctic was then dominated by boreal evergreen coniferous trees, whereas at lower latitudes the taiga forest belt and the Sino-Himalayan forest belt were composed of temperate broad-leaved deciduous trees (31 Forrest, M., J. T. Eronen, T. Utescher, G. Knorr, C. Stepanek, G. Lohmann, and T. Hickler (2015). Climate-vegetation modelling and fossil plant data suggest low atmospheric CO2 in the late Miocene. Climate of the Past 11:1701 – 1732. Close ). Thus, the separation of the Siberian Nuthatch from related nuthatch species was likely associated with adaptation to different climate regimes and forest ecosystems, and it represents an ancient relict form that is endemic to the far northeastern Palearctic (28 Packert, M., M. Bader-Blukott, B. Künzelmann, Y.-H. Sun, Y.-C. Hsu, C. Kehlmaier, F. Albrecht, J. C. Illera, and J. Martens (2020). A revised phylogeny of nuthatches (Aves, Passeriformes, Sitta) reveals insight in intra- and interspecific diversification patterns in the Palearctic. Vertebrate Zoology 70:241–262. Close ).

None known.

Monotypic (28 Packert, M., M. Bader-Blukott, B. Künzelmann, Y.-H. Sun, Y.-C. Hsu, C. Kehlmaier, F. Albrecht, J. C. Illera, and J. Martens (2020). A revised phylogeny of nuthatches (Aves, Passeriformes, Sitta) reveals insight in intra- and interspecific diversification patterns in the Palearctic. Vertebrate Zoology 70:241–262. Close ).

The Siberian Nuthatch is neither nested within the Eurasian Nuthatch clade nor is it the sister to this widespread species as previously assumed (22 Zink, R. M., S. V. Drovetski, and S. Rohwer (2006). Selective neutrality of mitochondrial ND2 sequences, phylogeography and species limits in Sitta europaea. Molecular Phylogenetics and Evolution 40:679–686. Close ; 32 del Hoyo, J., and N. J. Collar (2016). HBW and BirdLife International Illustrated Checklist of the Birds of the World. Volume 2: Passerines. Lynx Edicions, Barcelona, Spain. Close ). Lineage separation from its closest relatives dates back at least to the late Miocene (28 Packert, M., M. Bader-Blukott, B. Künzelmann, Y.-H. Sun, Y.-C. Hsu, C. Kehlmaier, F. Albrecht, J. C. Illera, and J. Martens (2020). A revised phylogeny of nuthatches (Aves, Passeriformes, Sitta) reveals insight in intra- and interspecific diversification patterns in the Palearctic. Vertebrate Zoology 70:241–262. Close ).

The breeding range of the Siberian Nuthatch borders and even partly overlaps with the ranges of three subspecies of the Eurasian Nuthatch: At the western edge of its range, on the west side of the Yenisei basin, its range abuts that of Sitta europaea asiatica; across much of the southern portion of its range, in Yakutia (officially, Republic of Sakha), it is partly sympatric with Sitta europaea baicalensis; at the far eastern edge of its range, in the valley of the Penzhina River, it encounters Sitta europaea albifrons (1 Red’kin, Y., and M. Konovalova (2006). Systematic notes on Asian birds. 63. The eastern Asiatic races of Sitta europaea Linnaeus, 1758. Zoologische Mededelingen Leiden 80(5):241–261. Close ). Evidence of hybridization is limited to a bird collected at Ayan Village on the Sea of Okhotsk that was identified as a Siberian Nuthatch x Eurasian Nuthatch (33 Portenko, L. A. (1937). [Avifauna of the Polar Urals]. Academy of Sciences of the USSR, Moscow-Leningrad, Russia. (In Russian.) Close ). On the other hand, Kistchinski and Lobkov pointedly noted the absence of such hybrids (34 Kistchinski, A. A. and E. G. Lobkov (1979). Spatial relationships between some bird sub-species in the Beringian forest-tundra. Moskovskoe Obschestvo I Spytatelei Prirody. Otdel Biologicheskii, Biulleten, Novaia Seriia 5:11–23. Close ), and no evidence of hybrids involving the Siberian Nuthatch were found in museum collections by Red'kin and Konolova (1 Red’kin, Y., and M. Konovalova (2006). Systematic notes on Asian birds. 63. The eastern Asiatic races of Sitta europaea Linnaeus, 1758. Zoologische Mededelingen Leiden 80(5):241–261. Close ).

No information available.