About Sitta tephronota Sharpe, 1872
The eastern rock nuthatch (scientific name Sitta tephronota Sharpe, 1872) measures 15–16 cm in length. It is one of the least brightly colored nuthatches, with pale blue-grey upperparts, a white breast, and a belly that grades from white to pale orange-buff on the undertail coverts. A bold black eyestripe marks its head. Subspecies of this species vary in size: they are smaller in the eastern part of their range and largest in the west. The subspecies S. t. iranica and S. t. tephronota are the smallest, weighing 30–39 g, while S. t. dresseri is the largest, weighing 42.7–55 g. Although S. t. dresseri does not have as long a body as the giant nuthatch, it is the heaviest subspecies in the entire nuthatch family.