Wood nuthatch
The Eurasian nuthatch (Sitta europaea ) is a small passerine bird found throughout the Palearctic and in Europe. Nuthatches forage for insects hidden in or under bark by climbing along tree trunks and branches, sometimes upside-down, and advertise their territory using loud, simple songs.
The adult male of the nominate subspecies, S. e. europaea is 14 cm (5.5 in) long with a 22.5–27 cm (8.9–10.6 in) wingspan. It weighs 17–28 g (0.6–1 oz). It has blue-grey upperparts, a black eye-stripe, and a whitish throat and underparts. The flanks and lower belly are orange-red, mottled with white on the undertail. The stout bill is dark grey with a paler area on the base of the lower mandible, the iris is dark brown and the legs and feet are pale brown or greyish. Most other members of the S. e. europaea group differ only in detail from the nominate form, often with respect to the hue of the underparts, but S. e. arctica is quite distinctive. It is large, pale, has a white forehead and a reduced eye stripe, and it has more white in the tail and wings than any other subspecies. Nuthatches move on trees with short leaps and do not use their tails for support. In flight, they have a characteristic appearance, with a pointed head, round wings, and a short, square tail. Their flight is fast, with wings closed between beats, and is usually of short duration.
The female is similar in appearance to the male but may be identified by her slightly paler upperparts, a browner eyestripe, and a more washed-out tone to the flanks and lower belly. In the eastern form, S. e. asiatica, some males have buff underparts like the female, and birds with this appearance are difficult to sex in the field. Young birds resemble the female, although their plumage is duller and they have paler legs. Individuals can be reliably sexed as female from about 12 days old by their paler and buffer flanks, or, in some white-breasted subspecies, by the creamier hue of their underparts.
Eurasian nuthatches occur across temperate Eurasia from Great Britain (but not Ireland) to Japan. They breed south to the Mediterranean in Europe. In the east, their range includes most of China and Taiwan, and much of Korea. Most populations are sedentary, apart from some post-breeding dispersal of young birds. Northern and eastern breeders are dependent on the cones of the Siberian stone pine, and if the crop fails many birds may move west into northern Sweden and Finland in autumn, sometimes staying to breed. Eurasian nuthatches inhabit mature woodland with large, old trees, which provide extensive growth for foraging and nesting holes. In Europe, the deciduous or mixed forest is favored, particularly when containing oak. Parks, old orchards, and other wooded habitats may also be occupied. Particularly in mountains, old spruce and pine forests are used, and pine is also favored in Taiwan.
Eurasian nuthatches usually spend their time singly or in pairs. They feed during the day searching for food mainly on tree trunks and large branches, but smaller branches may also be investigated, and food may be taken from the ground, especially outside the breeding season. Nuthatches can forage when descending trees head first, as well as when climbing. Some prey is caught in flight, and a nuthatch will remove bark or rotten wood to reach insects. A pair may temporarily join a mixed-species foraging flock as it passes near their territory. Eurasian nuthatches also frequently visit bird tables and bird feeders in winter. They store their food year-round, but mainly in autumn, and hide seeds in cracks in the bark, occasionally in walls or in the ground. The food item is then usually concealed with lichen, moss, or small pieces of bark. Eurasian nuthatches call frequently, usually with a loud, sharp ‘dwip’ normally repeated twice or more often if excited. They also have a shrill ‘sirrrr or tsi-si-si’alarm call, and a thin ‘tsit’ pre-flight call. Their song is a slow whistled ‘pee-pee-pee’ with many variants, including a faster version, and may be intermingled with the call.
Eurasian nuthatches are carnivores (insectivores), meaning they eat mainly insects, particularly caterpillars and beetles. In autumn and winter, their diet is supplemented with nuts and seeds, hazelnuts and beech mast being preferred. The young are fed mainly on the insects favored by their parents, with some seeds.
Eurasian nuthatches are monogamous breeders and a pair occupies a breeding territory in which it spends the winter as well. The male sings to defend his territory and attract a mate. Both sexes have a courtship display with a floating, quivering flight, and the male will also make circular flights with a spread tail and raised head. He will also feed the female while courting her. These birds nest in a tree cavity and often re-use the same nest site in subsequent years. The nest site is typically 2-20 m (7-66 ft) above the ground and has a deep base of pine bark or chips of other wood, rarely supplemented with dry plant material. If the entrance to the hole is too large, it is plastered with mud, clay, and sometimes dung to make it smaller. The female lays a clutch of 6-9 red-speckled white eggs, although up to 13 eggs can sometimes be laid. The female incubates the eggs for 13-18 days and broods the altricial (helpless) downy chicks until they fledge 20-26 days later. Both adults feed the chicks in the nest and continue after they fledge until they become independent in about 8-14 days. Normally only one brood is raised each year.
Eurasian nuthatches are common throughout much of their range and are not considered threatened, although fragmentation of woodland can lead to local losses of breeding birds.
According to IUCN Red List, the total population size of the Eurasian nuthatch is 10,000,000-500,000,000 mature individuals. In Europe, the breeding population consists of 10,700,000-21,400,000 pairs, which equates to 21,400,000-42,800,000 mature individuals. National population estimates include around 10,000-100,000 breeding pairs in China, around 10,000-100,000 breeding pairs in Taiwan, around 10,000-100,000 breeding pairs in Korea, and around 10,000-100,000 breeding pairs in Japan. Currently, this species is classified as Least Concern (LC) on the IUCN Red List and its numbers today are stable.
