Siberian Nuthatch
Sitta arctica
西伯利亚䴓
Introduction
Species in family Sittidae. Originally described as Sitta arctica in 1907 by Sergei Buturlin, long considered a subspecies of the Eurasian nuthatch (S. europaea) until differentiated in 2006 based on morphological and molecular characters. Inhabits forests northeast of Lake Baikal, extending to the Bering Sea and Sea of Okhotsk, but not coastal areas. Range covers northwestern Siberia, barely exceeding the 105th meridian east. Inhabits Daurian larch (Larix gmelinii) stands on floodplains. Characterized by marginally larger average size than Eurasian nuthatch, distinct bill shape, larger claws, darker underwing-coverts, and outer rectrices white for more than half their length. Song described as distinctly different. IUCN assessment: least concern, with vast range of 3,910,000 km² and stable population.
Description
Medium-sized nuthatch approximately 15 cm in length. Upperparts dull blue-grey, darker than most Eurasian nuthatch subspecies; underparts brilliant white. Black eyestripe is thinner and shorter than in Eurasian nuthatch, with no clear mark on forehead above this line. Rufous brown of rump extends further down the flanks. Underwing-coverts dark grey (not pale); outer rectrices white for more than half their length. No apparent sexual dimorphism in plumage. Bill longer and narrower than Eurasian nuthatch, with straight upper margin and curved lower lower margin. Wing more pointed; seventh primary remige equals second in size. Tarsus shorter than Eurasian nuthatch, but hind claw is more developed, equaling remainder of toe at approximately 10 mm. Male measurements: 14.8 cm length, 25.7 cm wingspan, 86.4 mm folded wing, 18.6 mm bill, 49.9 mm tail, 17.0 mm tarsus. Female measurements: 15.1 cm length, 25.2 cm wingspan, 83.9 mm folded wing, 19.1 mm bill, 46.7 mm tail, 16.9 mm tarsus. Male weight 17.2-23.5 g (average 21.2 g); female weight 19.7-22.1 g.
Identification
Very similar in appearance to white-breasted subspecies of Eurasian nuthatch. Distinguished by marginally larger average size. Key distinguishing features include: darker, duller blue-grey upperparts; thinner, shorter black eyestripe; rufous rump color extending further onto flanks; dark grey underwing-coverts (pale in Eurasian); outer rectrices white for more than half their length; longer, narrower bill with straight upper margin; more pointed wing shape; and notably larger hind claw (approximately 10 mm). Bill base densely covered with long feathers. Unlike Eurasian nuthatch, no clear forehead mark above black eyestripe.
Distribution & Habitat
Endemic to central and northeastern Siberia, Russia. Western distribution begins around 105th meridian east, near upper reaches of Nizhnyaya Tunguska River and Vilyuy River in north (65th-67th parallel north) and Lena River in south. Eastern limit at lower Anadyr River, northwestern Koryak Mountains, and sources of Punjina River. Does not reach coastal areas of Bering Sea or Sea of Okhotsk. Replaced by S. e. asiatica in south and S. e. albifrons in Kamchatka Peninsula. Inhabits Daurian larch forests primarily on floodplains. Nomadic in winter; recorded as vagrant as far west as northern Europe.
Behavior & Ecology
During fall and winter, forms mixed-species foraging flocks with Eurasian nuthatch subspecies S. e. asiatica and S. e. baicalensis. Song described as powerful and distinctly different from Eurasian nuthatch. Pairs form by mid-May. Like other nuthatches, occasionally reuses Great spotted woodpecker (Dendrocopos major) nest cavities, plastering entrance with mud to reduce diameter. Young fledge between 30 June and 4 July.
Conservation
IUCN assessed as least concern in October 2016. Range covers 3,910,000 km². Population is large and stable, not warranting higher threat level. No subspecies distinguished. No specific threats identified in source.
Culture
No cultural significance, folklore, or mythology information provided in source.
Source: Wikipedia · CC BY-SA 3.0
Taxonomy
- Order
- Passeriformes
- Family
- Sittidae
- Genus
- Sitta
- eBird Code
- eurnut6
Distribution
north-central Siberia to Anadyr River (eastern Russia)
Data Sources
Species description from Wikipedia, licensed under CC BY-SA 3.0.
Taxonomy data from AviList 2025.