A 2006 taxonomic study examined the Siberian form arctica within the Eurasian Nuthatch group and supported treating it as a separate species. That form has dark bluish-grey upperparts, a white belly centre and chestnut flanks. A current species account lists forest habitat and invertebrates as food, but the taxonomic study says ecological information about arctica remains fragmentary.
The systematic review describes arctica as dark bluish-grey above, with a pure-white centre to the belly and chestnut flanks. It also notes a narrower, shorter black stripe along the side of the head than in the other white-bellied forms it compared.
A current Sitta arctica account lists forest as habitat and invertebrates as food. The 2006 review cautions that ecological information about arctica is fragmentary.
An extinction-risk assessment has not been added yet.