Krüper's Nuthatch

The Krüper's nuthatch is a small to medium-sized nuthatch, measuring 12.5 centimetres (4.9 in) in length. In males and females, the folded wing measures 71–81 millimetres (2.8–3.2 in) and 68–74 millimetres (2.7–2.9 in) respectively, the tail 33–40 millimetres (1.3–1.6 in) and 33–38 millimetres (1.3–1.5 in). The bill measures 17.9–20.2 millimetres (0.70–0.80 in) and the tarsus 16.9–19.3 millimetres (0.67–0.76 in). The adult male weighs 10–14.3 grams (0.35–0.50 oz). The study of 41 different measurements of many individuals across different localities in Turkey showed small variations in size along the range. The upperparts are blue-grey with a black front crown in adults of both sexes, and the primary and secondary flight feathers are grey-brown. The supercilium is white and underlined by a black eyestripe that is a little less well defined behind the eye. The throat is white and the rest of the underparts are pale grey with a large reddish patch on the crescent-shaped breast. The underwing-coverts are off-white and the undertail is rufous, with white tips. The eye is surrounded by a thin white eye ring, and the iris is dark cinnamon or brown; the bill is dark horn-grey; the upper mandible cutting edge at the base is blue-grey, as is the entire lower mandible base. …

Krüper's nuthatch is found almost entirely in Turkey, where it is common in western Anatolia, and where it also lives along the Mediterranean coast in the Taurus Mountains and along the Black Sea coast north of the country, as far east as southern Georgia. It also lives on the Greek island of Lesbos and is vagrant in mainland Greece, where one was observed at Thessaloniki in October 1955. In 2010, a new nesting area was reported in central Anatolia, in Yozgat province, in the Ak Dağları mountains. This site consists of pure Scots pine (Pinus sylvestris) forest, and may support around 560 individuals. Krüper's nuthatch has a very close relationship with the Turkish pine (Pinus brutia), and the range of the bird almost completely overlaps that of the tree. Outlying populations of Turkish pine in the Crimea, northwestern Syria, Lebanon, northern Iraq, and Azerbaijan, which are mostly small, may have once held Krüper's nuthatches, or may still hold undiscovered populations. Krüper's nuthatch is sedentary, but undertakes some dispersal after the breeding season. Seasonal altitudinal shifts have also been noted, with some birds, possibly bird in their first year, moving down from the high ground in winter to mixed or deciduous forests. …

The Krüper's nuthatch lives alone or in pairs during the breeding season, and the pair stays with their young. In autumn, it is observed in groups of two to five individuals, sometimes taking part in mixed-species foraging flocks.

Vocalisations. The Krüper's nuthatch is a noisy bird, and is often easily detected and identified by its calls. The contact call is a dvui, sometimes made in a dui-dui-dui-dui series and reminiscent of the European greenfinch (Chloris chloris). When agitated, it produces a rough èèhch reminiscent of the Eurasian jay (Garrulus glandarius) or a dry puik. The song is a "tutitutitutitutituti… nasal, alternating high and low notes", with variable rhythm between different song strophes.

Food. The Krüper's nuthatch is an active bird, and it finds its food among the smallest branches in the tops of large trees, but also in other levels of vegetation. It can forage in bushes, and even feed on the ground. It feeds mainly on insects during the breeding season, but when these become scarce, in autumn and winter, it consumes seeds of pine and other conifers. Insects are gleaned along branches, or caught in flight, and conifer seeds are extracted from cone scales with the bill, before being wedged into a crack in the bark and hammered open. …