This species has been split by Rasmussen and Anderton (2005) from: the Indian nuthatch and Burmese nuthatch. The chestnut-bellied nuthatch is very similar to the previous but with a heavier bill, crown and mantle of the same shade. The wing and tail markings show contrasting markings; silvery-edge to primaries, blackish inner webs to tertials and tail with large white spots in the tail. White on ear coverts does not extend into chin unlike in the former. Race almorae of Nepal and NW Himalayas has paler underparts; race koelzi of the eastern Himalayas has the female darker than in other races. Resident from Murree Hills to the Uttaranchal foothills extending to the Assam Valley, Arunachal Pradesh into the Lushai Hills.
- Rasmussen, P. C. & J. Anderton (2005) The Birds of South Asia:The Ripley Guide. Smithsonian Institution and Lynx Edicions.