Krüper's nuthatch (Sitta krueperi) is a species of bird in the family Sittidae. It is a small to medium-sized nuthatch, measuring 12.5 centimetres in length. The upperparts are blue-gray, with the front half of the crown black in adults of both sexes, but with a less marked in the female rear. The species has a black or gray eyestripe and a prominent white supercilium. The underparts are blue-gray in males and buff-gray in females, with a large, crescent-shaped rufous pectoral patch. The Krüper's nuthatch feeds on insects in the summer and seeds, especially pines, in the fall and winter. Breeding takes place between March and May, and the nest is usually placed in a tree hole. The clutch consists of five to seven eggs, incubated by the female and fed by the male. Both parents take part in feeding the young. The Krüper's nuthatch is found in pine and other coniferous forests in Turkey, Lesvos, and the Caucasus, largely following the distribution of Turkish pine (Pinus brutia). It is found from sea level up to 2,500 metres (8,200 ft) above sea level in places. This species is one of the small nuthatches of the "canadensis group" and is particularly very close to the Algerian nuthatch (S. ledanti), the only other species in which the black half-crown is found. The Krüper's nuthatch is threatened by habitat loss caused by forestry and especially by tourist development on the Turkish coasts.