Short-toed Treecreeper is one of a group of four very similar Holarctic treecreepers, including the closely related North American Brown Creepers, and has five subspecies differing in appearance and song. Like other treecreepers, Short-toed is inconspicuously plumaged brown above and whitish below, and has a curved bill and stiff tail feathers. It is a resident in woodlands throughout its range, and nests in tree crevices or behind bark flakes, laying about six eggs. This common, unwary, but inconspicuous species feeds mainly on insects which are picked from the tree trunk as the treecreeper ascends with short hops.
The Short-toed Treecreeper is 12.5 centimetres (5 in) long and weighs 7.5–11 grams (0.26–0.39 oz). It has dull grey-brown upperparts intricately patterned with black, buff and white, a weak off-white supercilium and dingy underparts contrasting with the white throat. The sexes are similar, but juveniles have whitish underparts, sometimes with a buff belly.
The call of this species is a repeated shrill tyt...tyt tyt-tyt and the song of the nominate subspecies is an evenly spaced sequence of notes teet-teet-teet-e-roi-tiit. There is some geographical variation; the song of Danish birds is shorter, that of the Cyprus subspecies is very short and simple, and the North African version is lower pitched. European birds do not respond to latter two song variants.
This species shares much of its range with the Common Treecreeper. Compared to Short-toed, that bird is whiter below, warmer and more spotted above, and has a whiter supercilium and slightly shorter bill. However, identification by sight may be impossible for poorly-marked birds. Vocal birds are usually identifiable, since Common has a distinctive song composed of twitters, ripples and a final whistle and a shree' call rarely given by Short-toed; however, both species have been known to sing the other's song. Even in the hand, although Short-toed usually has a longer bill and shorter toes, 5% of birds are not safely identifiable.
Brown Treecreeper has never been recorded in Europe, but would be difficult to separate from Short-toed Treecreeper, which it much resembles in appearance. Its call is more like Common Treecreeper's, but a vagrant Brown Treecreeper might still not be possible to identify with certainty given the similarities between the three species.
|C. b. megarhyncha||Channel Islands and western Europe in northwest Spain, western and northern France, Belgium, the Netherlands and western Germany.||See "Description". Western birds are paler and more rufous than those further east.|
|C. b. brachydactyla||Continental Europe east of C. b. megarhyncha, Sicily and Crete.||The Nominate subspecies; darker and colder brown above and more clearly white-streaked below than C. b. megarhyncha.|
|C. b. mauritanica||North Africa.||Darker and colder brown upperparts and more extensively buff-washed underparts than nominate subspecies. Different song.|
|C. b. dorotheae||Cyprus.||Greyer upperparts and purer white underparts than nominate. Different song.|
|C. b. harterti||Asia Minor and the Caucasus.||Similar to C. b. megarhyncha, but duller rufous upperparts.|
The Short-toed Treecreeper breeds in temperate woodlands across Europe from Portugal to Turkey and Greece, and in north west Africa. It prefers well-grown trees, especially oak and avoids pure stands of conifers. Where it shares its European range with Common Treecreeper, the latter species tends to be found mainly in coniferous forest and at higher altitudes.
It is usually found in the lowlands, but breeds locally at up to 900 metres (2950 ft) in Germany, 1800 metres (5900 ft) France and 1400 metres (4590 ft) in Switzerland. In Turkey and North Africa it is a mountain species. The breeding areas have July isotherms between 17–18 oC and 26 oC (63–64 oF and 79 oF).
This treecreeper is essentially non-migratory but post-breeding dispersal may lead to vagrancy outside the normal range. It has occurred as a vagrant to England, Sweden, Lithuania and the Balearic Islands. Three birds on Corsica in 1969 appeared to be of the North African subspecies C. b. mauritanica.
The Short-toed nests in tree crevices or behind bark flakes. Old woodpecker nests, crevices in buildings or walls, and artificial nest boxes or flaps are also used.
The nest has an often bulky base of twigs, pine needles, grass or bark, and a lining of finer material such as feathers, wool, moss, lichen or spider web. The eggs are laid between April and mid June (typical clutch 5–7 eggs); they are white with purple-red blotches, 15.6 x 12.2 mm (0.6 x 0.5 in) in size. The eggs are incubated by the female alone for 13 - 15 days until the altricial downy chicks hatch; they are then fed by both parents, but brooded by the female alone, for a further 15 - 18 days to fledging. This species often raises a second brood. The male starts constructing a new nest while the female is still feeding the first brood, and when the chicks are 10-12 days old, he takes over feeding duties while the female completes the new nest.
A Spanish study suggests that forest fragmentation adversely affects the numbers of Short-toed Treecreepers present, as is also the case with the Common Treecreeper. Species that depend on relatively scarce resources, such as tree trunks, only occupy the larger forests, whereas those such as tits and Firecrests that exploit abundant, ubiquitous resources are distributed uniformly through woodlands of all sizes.