The short-toed treecreeper (Certhia brachydactyla) is a small passerine bird found in woodlands through much of the warmer regions of Europe and into north Africa. It has a generally more southerly distribution than the other European treecreeper species, the common treecreeper, with which it is easily confused where they both occur. The short-toed treecreeper tends to prefer deciduous trees and lower altitudes than its relative in these overlap areas. Although mainly sedentary, vagrants have occurred outside the breeding range. The 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, the 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. Taxonomy The short-toed treecreeper was first described by Christian Ludwig Brehm in 1820. The binomial name is derived from Greek; kerthios is a small tree-dwelling bird described by Aristotle and others, and brachydactyla comes from brakhus, "short" and dactulos "finger", which refers, like the English name, to the fact that this species has shorter toes than the common treecreeper. This species is one of a group of very similar treecreeper species, all placed in the single genus Certhia. Eight species are currently recognised, in two evolutionary lineages, a Holarctic radiation, and a Sino-Himalayan group south and east of the Himalayas. The former group has a more warbling song, always (except in C. familiaris from China) starting or ending with a shrill sreeh. The Himalayan species, in contrast, have a faster-paced trill without the sreeh sound. The short-toed treecreeper belongs to the northern group, along with the North American brown creeper, C. americana, the common treecreeper, C. familaris, of temperate Eurasia, and Hodgson's treecreeper, C. hodgsoni, from the southern rim of the Himalayas. Subspecies There are five subspecies of short-toed treecreeper, which are all very similar and often intergrade in areas where their ranges overlap. There is a general cline in appearance from west to east across Europe, with upperparts becoming a darker and colder brown. The currently recognised subspecies are as follows: