chestnut-vented nuthatch

The chestnut-vented nuthatch was described as Sitta nagaensis in 1874 by the British naturalist Henry Haversham Godwin-Austen.{{cite journal |last=Godwin-Austen |first=H. H. |author-link=Henry Haversham Godwin-Austen |date=January 1874 |url=https://archive.org/details/proceedingsofgen74zool?view=theater#page/44/mode/2up |title=Descriptions of Ten new Birds from the Nágá Hills and Munipúr Valley, NE Frontier of Bengal |journal=Proceedings of the Zoological Society of London |volume=42 |issue=1 |page=44 |via=Internet Archive}} Its species name is composed of naga and the Latin suffix -ensis, "that lives in, that inhabits", and was given in reference to the area when the type of the species was collected, the Naga Hills.{{cite journal |last=Pittie |first=Aasheesh |date=2004 |url=https://archive.org/details/BirdNamesIndia/page/n15/mode/2up?view=theater |title=A dictionary of scientific bird names originating from the Indian area |journal=Buceros |volume=9 |issue=2 |page=17 |via=Internet Archive}} The chestnut-vented nuthatch is placed in the rarely-used subgenus Sitta (Linnaeus, 1758).{{cite book |last=Matthysen |first=Erik |others=Illustrated by David Quinn |date=2010 |url=https://books.google.com/books?id=I-Smj_ufIikC |title=The Nuthatches |location=London |publisher=A & C Black |page=355 |isbn=978-1-4081-2870-1 |via=Google Books}}

In 2014, Eric Pasquet and colleagues published a phylogeny based on examination of nuclear and mitochondrial DNA of 21 nuthatch species.{{Cref2|fn. 2}} The europaea group is related to the two nuthatches that live in rocky environments, the western rock nuthatch (S. neumayer) and the eastern rock nuthatch (S. tephronota). Within the europaea group, the white-tailed nuthatch (S. himalayensis) and therefore probably the white-browed nuthatch (S. victoriae), which closely resembles it in terms of its morphology, although it was not included in the study, appear to be basal, and the chestnut-vented nuthatch is closely related to the Eurasian nuthatch (S. europaea) and the Kashmir nuthatch (S. cashmirensis).

{{clade gallery |width=375px; |height=400px;

|main-caption=Phylogenetic relationship of chestnut-vented nuthatch with other nuthatches

|footer1=Nuthatch relationships according to Pasquet, et al. (2014).

|cladogram1=

{{clade

|label1=

|1={{clade

|1=Beautiful nuthatch (S. formosa)

|2={{clade

|1={{clade

|1=Eastern rock nuthatch (S. tephronota)

|2=Western rock nuthatch (S. neumayer)

}}

|2={{clade

|1=White-tailed nuthatch (S. himalayensis)

|2={{clade

|1=Kashmir nuthatch (S. cashmirensis)

|2=Chestnut-vented nuthatch (S. nagaensis)

|3=Eurasian nuthatch (S. europaea)

}}

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|footer2=Nuthatch relationships according to Päckert et al. (2020).{{ cite journal | last1=Päckert | first1=M. | last2=Bader-Blukott | first2=M. | last3=Künzelmann | first3=B. | last4=Sun | first4=Y.-H. | last5=Hsu | first5=Y.-C. | last6=Kehlmaier | first6=C. | last7=Albrecht | first7=F. | last8=Illera | first8=J.C. | last9=Martens | first9=J. | date=2020 | title=A revised phylogeny of nuthatches (Aves, Passeriformes, Sitta) reveals insight in intra- and interspecific diversification patterns in the Palearctic | journal=Vertebrate Zoology | volume=70 | issue=2 | pages=241–262 | doi=10.26049/VZ70-2-2020-10 | doi-access=free }}

|cladogram2=

{{clade

|1={{clade

|1={{clade

|1=Western rock nuthatch (Sitta neumayer)

|2=Eastern rock nuthatch (Sitta tephronota)

}}

|2={{clade

|1=Siberian nuthatch (Sitta arctica)

|2={{clade

|1={{clade

|1=White-browed nuthatch (Sitta victoriae)

|2=White-tailed nuthatch (Sitta himalayensis)

}}

|2={{clade

|1=Eurasian nuthatch (Sitta europaea)

|2={{clade

|1=Chestnut-vented nuthatch (Sitta nagaensis)

|2={{clade

|1=Kashmir nuthatch (Sitta cashmirensis)

|2={{clade

|1=Indian nuthatch (Sitta castanea)

|2={{clade

|1=Chestnut-bellied nuthatch (Sitta cinnamoventris)

|2=Burmese nuthatch (Sitta neglecta)

}}

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There are three accepted subspecies of the chestnut-vented nuthatch.{{cite web |url=http://www.worldbirdnames.org/bow/nuthatch/ |title=Nuthatches, Wallcreeper, treecreepers, mockingbirds, starlings & oxpeckers |date=22 October 2016 |publisher=International Ornithological Congress |version=6.4 |at=Family Sittidae |archive-url=https://web.archive.org/web/20161222041438/http://www.worldbirdnames.org/bow/nuthatch/ |archive-date=22 December 2016 |url-status=dead |via=Internet Archive}}

• S. n. montium (La Touche, 1899), described by the Irish ornithologist John La Touche (with the protonym Sitta montium) as a montane taxon altitudinally separated from S. europaea sinensis,{{cite journal |last=La Touche |first=John David Digues |date=1899 |url=https://archive.org/details/ibis57brit/page/404/mode/2up?view=theater |title=Note on the birds of North-west Fohkien |journal=The Ibis |series=Series 7 |volume=5|issue=19 |pages=(403–)404 |via=Internet Archive|doi=10.1111/j.1474-919X.1899.tb01490.x}} it occurs in eastern Tibet, southern and eastern China, Myanmar, and northwest Thailand.
• S. n. nagaensis (Godwin-Austen, 1874), occurs in the Naga Hills in northeastern India and northwestern Myanmar.
• S. n. grisiventris (Kinnear, 1920), described from Mount Victoria in western Myanmar, under the protonym Sitta europaea grisiventris (since S. n. nagaesis was also then considered a subspecies of the Eurasian nuthatch S. europaea);{{cite journal |last=Kinnear |first=Norman Boyd |author-link=Norman Boyd Kinnear |date=31 May 1920 |url=https://archive.org/details/bulletinofb3840191720brit/page/142/mode/2up?view=theater |title=Mr. N. B. Kinnear exhibited and described a new form of Nuthatch from Burma|journal=Bulletin of the British Ornithologists' Club |volume=40 |page=142 |via=Internet Archive}} birds from southern Vietnam are also currently ascribed to this subspecies.

The subspecies S. n. montium was considered to possibly be the result of hybridisation between chestnut-vented nuthatch and the Chinese subspecies of Eurasian nuthatch Sitta europaea sinensis,{{cite book|last=McCarthy|first=Eugene M.|url=http://www.spinus.info/Images/books/AH743697479746.pdf|title=Handbook of Avian Hybrids of the World|date=January 2006|publisher=Oxford University Press|isbn=978-0-19-518323-8|pages=246–247|chapter=Nuthatches - Family Sittidae}} or at least to be able to interbreed with it.{{cite book |last=Harrap |first=Simon |others=Illustrated by David Quinn |title=Tits, Nuthatches and Treecreepers |date=1996|editor=Christopher Helm |publisher=Helm|isbn=0-7136-3964-4|pages=114–117}} This is possibly due to the fact that the type series of S. e. sinensis was composite and included a specimen of the chestnut-vented nuthatch. For these reasons, Jean-François Voisin and colleagues designated a lectotype in 2002 for the name Sitta sinensis (Verreaux, 1871).{{cite journal|last1=Voisin|first1=C.|last2=Voisin|first2=J.-F.|last3=Causey|first3=Douglas|last4=Dickinson|first4=E. C.|name-list-style=amp|date=2002|title=Systematic notes on Asian birds. 29. On the types of Sitta sinensis J. Verreaux, 1871, and Sitta montium La Touche, 1899|url=https://archive.wikiwix.com/cache/display2.php/attachment.pdf?url=http%3A%2F%2Frepository.naturalis.nl%2Fdocument%2F46727|journal=Zoologische Verhandelingen|location=Leiden|volume=340|issue=27|pages=191–196|isbn=90-73239-84-2}}{{cite journal|last=Dickinson|first=E. C.|date=2006|title=Systematic notes on Asian birds. 62. A preliminary review of the Sittidae|url=https://archive.wikiwix.com/cache/display2.php/attachment.pdf?url=http%3A%2F%2Fwww.repository.naturalis.nl%2Fdocument%2F41857|journal=Zoologische Verhandelingen|location=Leiden|volume=80|issue=14|pages=225–240}} The attribution of the populations of western Myanmar and southern Indochina to the same subspecies S. n. grisiventris, with S. n. montium in central Myanmar between these populations seems untenable, and their taxonomy has yet to be verified.{{cite journal|last=Harrap|first=Simon|name-list-style=amp|date=4 March 2020|title=Chestnut-vented Nuthatch (Sitta nagaensis)|url=https://birdsoftheworld.org/bow/species/chvnut1/cur/introduction|version=1.0|publisher=Cornell Lab of Ornithology|doi=10.2173/bow.chvnut1.01|editor-last4=Christie|editor-first5=E.|editor-last5=de Juana|editor-first4=D. A.|editor-last2=Elliott|editor-first3=J.|editor-last3=Sargatal|editor-first2=A.|editor-first1=J.|editor-last1=del Hoyo|journal=Birds of the World|s2cid=216229068|url-access=subscription}}

File: Chestnut-vented Nuthatch (Sitta nagaensis).jpg, Sichuan, China]]

The chestnut-vented nuthatch is a medium-sized nuthatch, measuring {{convert|12.5–14|cm|in|abbr=on}} in length. The {{birdgloss|upperparts}} are a solid blue-grey from crown to tail, with a marked black loral line extending to the base of the wing. The {{birdgloss|underparts}} are pale grey, more or less tinted buff-tinged depending on the subspecies or the wear of the plumage; the dark brick-red back flanks contrast strongly with the rest of the underparts. The {{birdgloss|undertail coverts}}, which may be of the same colour depending on the subspecies, have a large white border at the end of the feathers or a white patch near the tip.

The species does not show marked sexual dimorphism. The male's rear flanks are deep brick-red, deeper and less orange than the undertail coverts, whereas the female's flanks are rufous, concolorous with the undertail coverts. Females also have duller underparts, and juveniles are more buff than adults with worn plumage. The iris is brown to dark brown, the bill is greyish-black to blackish with the base of the lower mandible (and sometimes the base of the upper) slate-grey or blue-grey. The legs are dark brown, greenish or blue-grey, with almost black claws.

Three subspecies are accepted, but variation is essentially clinal, with Chinese populations (S. n. montium) having buff underparts, which get duller and purer grey as they move southward in the species' distribution. In Northeast India and western Myanmar, S. n. nagaensis in fresh plumage is as buff as S. n. montium in worn plumage. In southern Vietnam and southwestern Myanmar, S. n. grisiventris has purer grey underparts than S. n. nagaensis. Adults undergo a complete moult after the breeding season, from May to June, and an incomplete moult occurs before it.

File:White-tailed Nuthatch West Sikkim India 16.02.2016.jpg (S. himalayensis) has uniform underparts and is much more colourful than the chestnut-vented nuthatch.]]

The range of the chestnut-vented nuthatch overlaps with that of the Burmese nuthatch (S. neglecta). However, the chestnut-vented nuthatch is easily distinguished by the colour of its underparts, and the lack of contrast between the sides of the head and the throat, whereas the other species has white chins, cheeks, and parotid region contrasting with brick-red to orange-brown underparts. However, in the chestnut-vented nuthatch, some individuals in fresh plumage (especially in S. n. montium) may have underparts almost as buff as some Burmese nuthatch females or juveniles. The chestnut-vented nuthatch can then be recognised by its darker, duller blue upperparts, by its red flanks contrasting with the buff, and by its undertail, with feathers edged with red giving a "scales" pattern, when they appear almost uniformly white in the Burmese nuthatch.

The subspecies S. n. montium can also be confused with the subspecies S. e. sinensis of the Eurasian nuthatch (S. europaea) where they coexist in Sichuan and Fujian. As the latter subspecies has more orange underparts, some Eurasian females may be difficult to differentiate from chestnut-vented nuthatches in fresh plumage. The two species can be distinguished by their vocalisations, with chestnut-vented nuthatch lacking the characteristic singing dwip of the Euraisan nuthatch. Hybrids between these two taxa have been suggested, with montane populations of S. e. sinensis being, like the chestnut-vented nuthatch, greyer on the underside, darker above, and larger than lowland individuals. The chestnut-vented nuthatch, however, is even greyer, and does not have the whitish cheeks of the Eurasian nuthatch.

In southwest China, the chestnut-vented nuthatch lives within the range of the Yunnan nuthatch (S. yunnanensis). However, the latter is smaller, has a thin white supercilium, and has plain, pale buff underparts with no russet on the flanks.{{cite book |last=Harrap |first=Simon |others=Illustrated by David Quinn |title=Chickadees, Tits, Nuthatches and Treecreepers |date=1995 |editor=Christopher Helm |publisher=Princeton University Press |page=143 |isbn=0-691-01083-8}} In northeastern India and northwestern Myanmar, the chestnut-vented nuthatch can also be confused with the white-tailed nuthatch (S. himalayensis); both species share similar habitats. The white-tailed nuthatch, however, has a white spot on the top of the middle rectrices, and has more orange underparts, without brick-red flanks or white spots on the undertail. The giant nuthatch (S. magna), whose distribution overlaps with that of the chestnut-vented nuthatch in India, Myanmar, and Thailand, differs from the latter in being much larger in size, having a finer {{birdgloss|eyestripe}}, and having a {{birdgloss|crown}} that is much lighter than the rest of the {{birdgloss|mantle}}.

File:Yellow-cheeked Tit - Bhutan.jpg (Machlolophus spilonotus) may roam with the nuthatch in mixed-foraging flocks.]]

The chestnut-vented nuthatch generally lives alone or in pairs, but joins mixed-species foraging flocks outside of the breeding season. In winter, it can thus be observed in the company of different species of tits (Paridae) such as the yellow-cheeked tit (Maclolophus spilonotus), bushtits,{{cite journal|last1=Stanford|first1=J. K.|author1-link=J. K. Stanford|last2=Ticehurst|first2=Claud B.|author2-link=Claud B. Ticehurst|name-list-style=amp|date=January 1938|title=On the Birds of Northern Burma. Part I|url=https://onlinelibrary.wiley.com/doi/10.1111/j.1474-919X.1938.tb00185.x|journal=The Ibis|volume=80|issue=1|pages=65–102|doi=10.1111/j.1474-919X.1938.tb00185.x|via=Wiley Online Library|url-access=subscription}} woodpeckers,{{cite journal |last1=Schäfer |first1=Ernst |author1-link=Ernst Schäfer |last2=De Schauensee |first2=Rodolphe Meyer |author2-link=Rodolphe Meyer de Schauensee |date=1938 |url=https://www.jstor.org/stable/4064251 |title=Zoological Results of the Second Expedition to Dolan Western China and Eastern Tibet, 1934–1936. Part II: Birds |journal=Proceedings of the Academy of Natural Sciences of Philadelphia |volume=90 |pages=185–260 |jstor=4064251 }} alcippes, and minlas.{{cite journal|last1=Stanford|first1=J. K.|last2=Mayr|first2=Ernst|author2-link=Ernst Mayr|year=2008|title=The Vernay-Cutting Expedition to Northern Burma. Part II|url=https://onlinelibrary.wiley.com/doi/10.1111/j.1474-919X.1941.tb00596.x|journal=The Ibis|volume=83|issue=1|pages=56–105|doi=10.1111/j.1474-919X.1941.tb00596.x|via=Wiley Online Library|url-access=subscription}}

{{Birdsong|image=SittaNagaensis.png|species=Sitta nagaensis|url=https://xeno-canto.org/explore?query=Sitta%20nagaensis}}

The chestnut-vented nuthatch's calls are varied, with squeaky sit or sit-sit sounds, repeated more or less rapidly with various inflections and in irregular series. Similar but drier {{Not a typo|tchip}} or {{Not a typo|tchit}} sounds are sometimes made, often in a trill reminiscent of the alarm of a Eurasian wren (Troglodytes troglodytes). The alarm calls of the chestnut-vented nuthatch are reported in English-language literature as nasal sounds in {{Not a typo|quir}}, {{Not a typo|kner}} or {{Not a typo|mew}}, as well as an emphatic, metallic {{Not a typo|tsit}}, sometimes doubled or repeated in quick series. The song is a stereotyped, monotonous rattle or tremolo in {{notatypo|chichichichichi}} ... or {{notatypo|trr-rrrrrrr-ri}} ..., lasting less than a second or sometimes slowed down to {{notatypo|chi-chi-chi-chi-chi}} ... or {{notatypo|diu-diu-diu- diu-diu}} reminiscent of the song of the Eurasian nuthatch.

The chestnut-vented nuthatch often forages for food on the ground, on rocks, old stumps, or in trees. No specific information about the diet is known, but the species probably feeds on small arthropods and seeds.

Although the breeding season varies by region, it generally takes place in Thailand from March to May, March to June for India, April to early June for eastern Myanmar, and April to May in Fujian. On Nat Ma Taung, juveniles have been observed as early as March 31. According to observations made in Thailand and Vietnam, the construction of the nest begins in January. It is located at a height of about {{convert|10|m|in|abbr=on}} in the hole of a tree, or in a stump.

The chestnut-vented nuthatch, like the Eurasian nuthatch and other species of the family, may line the entrance of a cavity with mud to reduce the opening and thus avoid predation of the brood. The bottom of the nest is lined with pieces of bark and moss and topped with hair. Two to five eggs are laid, averaging {{convert|18.6|×|13.8|mm|in|abbr=on|sigfig=2}} in S. n. nagaensis and {{convert|18.3|×|14|mm|in|abbr=on|sigfig=2}} in S. n. montium. They are white, with red dots on a mottled reddish-purple background, the red dots mainly concentrated at the larger end of the egg.

The chestnut-vented nuthatch lives from Tibet to the mountains of Lâm Đồng province in southern Vietnam. In India, it is found only in the far eastern states of Arunachal Pradesh, Nagaland, Manipur, Assam and Meghalaya. The species lives in the Chin Hills of western Myanmar, but most of its distribution in Myanmar is in the eastern half of the country, from Kachin State to at least Shan State, and also into northwestern Thailand. It also nests in Tibet and south-central China, from western Sichuan to Yunnan and marginally in southwestern Guizhou. An isolated Chinese population also lives in northwestern Fujian, on Mount Huanggang. Two other isolated populations from the southernmost part of the species' distribution, one occurring in southern Vietnam on the Đà Lạt Plateau, another being reported in Laos on the Bolaven Plateau.{{cite book |last=Robson |first=Craig |date=September 2005 |title=New Holland Field Guide to the Birds of South-East Asia |publisher=New Holland Publishers |page=210 |isbn=9781843307464}}{{cite journal |last1=Duckworth |first1=J. W. |last2=Tizard |first2=R. J. |last3=Timmins |first3=R. J. |last4=Thewlis |first4=R. M. |last5=Robichaud |first5=W. G. |last6=Evans |first6=T. D. |name-list-style=amp |date=1998 |url=https://static1.squarespace.com/static/5c1a9e03f407b482a158da87/t/5c1fbe3888251bb6cac14f37/1545584194551/Duckworth-Laos.pdf |title=Bird records from Laos, October 1994-August 1995 |journal=Forktail |volume=13 |pages=33–68}}

The chestnut-vented nuthatch usually inhabits evergreen forests of the uplands, or forests and pine patches growing on dry ridges in the middle of evergreen forests. Locally, it also occurs in deciduous forests in northeastern India, in Quercus subsericea oak forests and alder groves in northeastern Myanmar, spruce forests (Picea sp.), fir forests (Abies sp.) or rhododendron stands in Yunnan, or poplar (Populus sp.) and walnut (Juglans sp.) in Sichuan. The altitudinal distribution ranges from {{convert|1400–2600|m|ft|abbr=on}} in India, Thailand, and Myanmar, occasionally occurring up to {{convert|3200|m|ft|abbr=on|sigfig=3}} in the latter. It also occurs from {{convert|1050–3500|m|ft|abbr=on}} in Tibet and Sichuan and up to {{convert|4570|m|ft|abbr=on|sigfig=3}} in Yunnan. The population in southern Vietnam lives between {{convert|915–2285|m|ft|abbr=on}}.

The population of the chestnut-vented nuthatch is declining due to habitat destruction and fragmentation, but its range is large and was estimated to be 3.8 million km² (1.5 million square miles), and the species is generally common throughout its range. For these reasons, the chestnut-vented nuthatch is considered to be of least concern by the International Union for the Conservation of Nature. A study carried out in 2009 tried to predict the impact of climate change on the distribution of several species of nuthatches in Asia by modeling two scenarios. It predicted that the chestnut-vented nuthatch could see its distribution decrease between the 2040s and 2069 by 15.9 to 17.4%.{{cite journal |last1=Menon |first1=Shaily |last2=Islam |first2=M. Zafar-ul |last3=Peterson |first3=A. Townsend |name-list-style=amp |date=31 August 2003 |url=http://scholarworks.gvsu.edu/cgi/viewcontent.cgi?article=1005&context=biopeerpubs |title=Projected climate change effects on nuthatch distribution and diversity across Asia |journal=The Raffles Bulletin of Zoology |volume=57 |issue=2 |pages=569–575}}

{{Cnote2|fn. 2|The 21 species are out of 24 species accepted as making up the genus by Simon Harrap and David Quinn as of 1996. Of these, the study omitted the Indian nuthatch (Sitta castanea), the yellow-billed nuthatch (Sitta solangiae) and the white-browed nuthatch (Sitta victoriae). The International Ornithological Congress however accepted 28 species in 2012, based on the elevation of four taxa from subspecies to full-species status, including Przevalski's nuthatch (S. przewalskii) and three species from the europaea group.{{cite journal |last1=Pasquet |first1=Eric |last2=Barker |first2=F. Keith |last3=Martens | first3=Jochen |last4=Tillier |first4=Annie |last5=Cruaud| first5=Corinne |last6=Cibois |first6=Alice |name-list-style=amp |date=April 2014 |title=Evolution within the nuthatches (Sittidae: Aves, Passeriformes): molecular phylogeny, biogeography, and ecological perspectives|journal=Journal of Ornithology |volume=155 |issue=3 |pages=755–765 |doi=10.1007/s10336-014-1063-7 |bibcode=2014JOrni.155..755P |s2cid=17637707}}}}

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chestnut-vented nuthatch

Category:Birds of Myanmar

Category:Birds of Yunnan

chestnut-vented nuthatch

Category:Taxonomy articles created by Polbot