Treecreeper
The Eurasian Treecreeper is a small passerine bird, also known in the UK, where it is the only member of its genus, simply as the Treecreeper.
Similar in appearance, all treecreeper species are small birds with streaked and spotted brown upperparts, rufous rumps and whitish underparts. They have long decurved bills and long rigid tail feathers that provide support as they creep up tree trunks looking for insects.
The Treecreeper is 4.9 inches and has warm brown upperparts intricately patterned with black, buff and white and a plain brown tail. The belly, flanks and vent area are tinged with buff. The sexes are similar but the juvenile has duller upperparts than the adult and the underparts are dull white with dark fine spotting on the flanks.
The range of the Treecreeper overlaps with that of several other treecreeper species which can present local identification problems. In Europe, the Treecreeper shares much of its range with the Short-toed Treecreeper. Compared to that species, it is whiter below, warmer and more spotted above and has a whiter supercilium and slightly shorter bill. Visual identification, even in the hand, may be impossible for poorly marked birds.
As a small woodland bird with cryptic plumage and a quiet call and song, the Treecreeper is easily overlooked as it hops mouse-like up a vertical trunk, progressing in short hops and using its stiff tail and widely splayed feet as support. However, it is not wary and it is largely indifferent to the presence of humans. It has a distinctive erratic and undulating flight, alternating fluttering butterfly-like wing beats with side-slips and tumbles.
The Treecreeper is the most widespread member of its genus and it breeds in temperate woodlands across the Palearctic from Ireland to Japan. It has an extensive range and a large population. It is common through much of its range but in the northernmost areas it is rare since it is vulnerable to hard winters.
The Treecreeper is non-migratory in the milder west and south of its breeding range but some northern birds move south in winter and individuals breeding on mountains may descend to a lower altitude in winter. Winter movements and post-breeding dispersal may lead to vagrancy outside the normal range.
The Treecreeper prefers mature trees and in most of Europe, where it shares its range with Short-toed Treecreeper, it tends to be found mainly in coniferous forest, especially spruce and fir. However, where it is the only treecreeper species, such as in the UK, it frequents broadleaved or mixed woodland in preference to conifers. It is also found in parks and large gardens.
The Treecreeper nests in tree crevices or behind bark flakes. Crevices in buildings or walls are sometimes used and artificial nest boxes may be used in coniferous woodland. The nest has a base of twigs, pine needles, grass or bark and a lining of finer material such as feathers, wool, moss, lichen or spider webs. The typical clutch of 5 to 6 eggs is laid between March and June and incubated by the female alone for 13 to 17 days. The chicks are fed by both parents but brooded by the female alone for a further 15 to 17 days to fledging. About 20% of pairs, mainly in the south and west, raise a second brood.
Predators of nests and young include the Great Spotted Woodpecker, Red and Grey Squirrels and small mustelids. The juvenile survival rate is unknown but around 50% of adults survive each year. The typical lifespan is 2 years but the maximum recorded age is 8 years and 10 months.
The Treecreeper typically seeks invertebrate food on tree trunks, starting near the tree base and working its way up using its stiff tail feathers for support. Unlike the Nuthatch, it does not come down trees head first but flies to the base of another nearby tree. It uses its long thin bill to extract insects and spiders from crevices in the bark. Although normally found on trees, it will occasionally hunt prey items on walls, bare ground or amongst fallen pine needles and it may add some conifer seeds to its diet in the colder months.
The Treecreeper may sometimes join mixed-species feeding flocks in winter but it does not appear to share the resources found by accompanying tit species and Goldcrests and may just be benefiting from the extra vigilance of a flock.
Date: 25th April 2022
Location: Sculthorpe Moor, Norfolk
Similar in appearance, all treecreeper species are small birds with streaked and spotted brown upperparts, rufous rumps and whitish underparts. They have long decurved bills and long rigid tail feathers that provide support as they creep up tree trunks looking for insects.
The Treecreeper is 4.9 inches and has warm brown upperparts intricately patterned with black, buff and white and a plain brown tail. The belly, flanks and vent area are tinged with buff. The sexes are similar but the juvenile has duller upperparts than the adult and the underparts are dull white with dark fine spotting on the flanks.
The range of the Treecreeper overlaps with that of several other treecreeper species which can present local identification problems. In Europe, the Treecreeper shares much of its range with the Short-toed Treecreeper. Compared to that species, it is whiter below, warmer and more spotted above and has a whiter supercilium and slightly shorter bill. Visual identification, even in the hand, may be impossible for poorly marked birds.
As a small woodland bird with cryptic plumage and a quiet call and song, the Treecreeper is easily overlooked as it hops mouse-like up a vertical trunk, progressing in short hops and using its stiff tail and widely splayed feet as support. However, it is not wary and it is largely indifferent to the presence of humans. It has a distinctive erratic and undulating flight, alternating fluttering butterfly-like wing beats with side-slips and tumbles.
The Treecreeper is the most widespread member of its genus and it breeds in temperate woodlands across the Palearctic from Ireland to Japan. It has an extensive range and a large population. It is common through much of its range but in the northernmost areas it is rare since it is vulnerable to hard winters.
The Treecreeper is non-migratory in the milder west and south of its breeding range but some northern birds move south in winter and individuals breeding on mountains may descend to a lower altitude in winter. Winter movements and post-breeding dispersal may lead to vagrancy outside the normal range.
The Treecreeper prefers mature trees and in most of Europe, where it shares its range with Short-toed Treecreeper, it tends to be found mainly in coniferous forest, especially spruce and fir. However, where it is the only treecreeper species, such as in the UK, it frequents broadleaved or mixed woodland in preference to conifers. It is also found in parks and large gardens.
The Treecreeper nests in tree crevices or behind bark flakes. Crevices in buildings or walls are sometimes used and artificial nest boxes may be used in coniferous woodland. The nest has a base of twigs, pine needles, grass or bark and a lining of finer material such as feathers, wool, moss, lichen or spider webs. The typical clutch of 5 to 6 eggs is laid between March and June and incubated by the female alone for 13 to 17 days. The chicks are fed by both parents but brooded by the female alone for a further 15 to 17 days to fledging. About 20% of pairs, mainly in the south and west, raise a second brood.
Predators of nests and young include the Great Spotted Woodpecker, Red and Grey Squirrels and small mustelids. The juvenile survival rate is unknown but around 50% of adults survive each year. The typical lifespan is 2 years but the maximum recorded age is 8 years and 10 months.
The Treecreeper typically seeks invertebrate food on tree trunks, starting near the tree base and working its way up using its stiff tail feathers for support. Unlike the Nuthatch, it does not come down trees head first but flies to the base of another nearby tree. It uses its long thin bill to extract insects and spiders from crevices in the bark. Although normally found on trees, it will occasionally hunt prey items on walls, bare ground or amongst fallen pine needles and it may add some conifer seeds to its diet in the colder months.
The Treecreeper may sometimes join mixed-species feeding flocks in winter but it does not appear to share the resources found by accompanying tit species and Goldcrests and may just be benefiting from the extra vigilance of a flock.
Date: 25th April 2022
Location: Sculthorpe Moor, Norfolk