Certhia familiaris macrodactyla Brehm, 1831
Common names: Eurasian treecreeper, Common treecreeper [En], Grimpereau des bois, Grimpereau familier [Fr], Taigaboomkruiper [Nl], Waldbaumläufer [De], Rampichino alpestre [It], Agateador norteño [Es], Βουνοδεντροβάτης [Gr], Orman tırmaşık kuşu [Tu]
IUCN Status: LC (Least Concern)
Hamoir, LIEGE ● Belgium
Description: This is a small passerine bird of 12.5 cm long, with a curved bill, patterned brown upperparts, whitish underparts, and long stiff tail feathers which help it creep up tree trunks. It has warm brown upperparts intricately patterned with black, buff and white, and a plain brown tail. Its belly, flanks and vent area are tinged with buff. The sexes are similar, but the juvenile has duller upperparts than the adult, and its underparts are dull white with dark fine spotting on the flanks.
It can be most easily distinguished from the similar short-toed treecreeper, which shares much of its European range, by its different song.
10 subspecies are recognised by the International Ornithological Congress:
• C. f. bianchii Hartert, 1905
• C. f. britannica Ridgway, 1882 – Great Britain and Ireland – Irish treecreepers are slightly darker than British ones
• C. f. caucasica Buturlin, 1907
• C. f. corsa Hartert, 1905 – Corsica – Buff-tinged underparts and more contrasted upperparts than C. f. macrodactyla
• C. f. daurica Domaniewski, 1922 – Eastern Siberia, northern Mongolia – Paler and greyer than the nominate subspecies
• C. f. macrodactyla Brehm, 1831 – Western Europe – Paler above and whiter below than C. f. Britannica
• C. f. familiaris Linnaeus, 1758– Scandinavia and eastern Europe east to western Siberia – Nominate subspecies. Paler above than C. f. macrodactyla, white underparts
• C. f. japonica Hartert, 1897 – Japan south of Hokkaido – Darker and more rufous than C. f. daurica
• C. f. persica Zarudny & Loudon, 1905 – The Crimea and Turkey east to northern Iran – Duller and less rufous than the nominate form
• C. f. tianchanica Hartert, 1905 – Northwestern China and adjacent regions of the former USSR – Paler and more rufous than nominate subspecies
Biology: The Eurasian treecreeper is easily overlooked as it hops mouse-like up a vertical trunk, progressing in short hops, using its stiff tail and widely splayed feet as support. Nevertheless, it is not wary, and 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. It is solitary in winter, but in cold weather up to a dozen or more birds will roost together in a suitable sheltered crevice.
The Eurasian treecreeper typically seeks invertebrate food on tree trunks, starting near the tree base and working its way up. It uses its long thin bill to extract insects and spiders from crevices in the bark.
The female Eurasian treecreeper forages primarily on the upper parts of the tree trunks, while the male uses the lower parts.
The Eurasian treecreeper breeds from the age of one year, nesting in tree crevices or behind bark flakes. In Europe, the typical clutch of five–six eggs is laid between March and June. The eggs are incubated by the female alone for 13–17 days until the altricial downy chicks hatch; they are then fed by both parents, but brooded by the female alone, for a further 15–17 days to fledging. Juveniles return to the nest for a few nights after fledging. About 20% of pairs, mainly in the south and west, raise a second brood.
Habitat: This species is found in woodlands of all kinds. It 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.
Distribution: This species has an extensive range, across Eurasia from Ireland to Japan. However, where it is the only treecreeper, as in European Russia, or the British Isles, it frequents broadleaved or mixed woodland in preference to conifers. It is also found in parks and large gardens.
The Eurasian treecreeper breeds down to sea level in the north of its range, but tends to be a highland species further south. In the Pyrenees it breeds above 1,370 metres, in China from 400–2,100 metres and in southern Japan from 1,065–2,135 metres.
It 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. Wintering migrants of the Asian subspecies have been recorded in South Korea and China, and the nominate form has been recorded west of its breeding range as far as Orkney, Scotland. The Eurasian treecreeper has also occurred as a vagrant to the Channel Islands (where the short-toed is the resident species), Majorca and the Faroe Islands.
It is common through much of its range, but in the northernmost areas it is rare, since it is vulnerable to hard winters. It is also uncommon in Turkey and the Caucasus. In the west of its range it has spread to the Outer Hebrides in Scotland, pushed further north in Norway.
Wikipedia, Eurasian treecreeper
BirdLife International. 2017, Certhia familiaris, The IUCN Red List of Threatened Species 2017