Przevalski's nuthatch (Sitta przewalskii), originally given the nomen nudum Sitta eckloni, is a bird species in the family Sittidae. Long regarded as a subspecies of the white-cheeked nuthatch (Sitta leucopsis), it nevertheless differs significantly in morphology and vocalizations. Both S. przewalskii and S. leucopsis have been regarded as closely related to the North American white-breasted nuthatch (Sitta carolinensis). It is a medium-sized nuthatch, measuring about 13 cm (5 in) in length. Its upper body is a dark gray-blue or slate color, becoming dark blue-black at the crown. The cheeks and throat are a white buff-orange, turning to a rich cinnamon on the underparts that intensifies in color on the sides of the breast. Vocalizations consist of alternating series of ascending whistles a