falls and then rises. The range of the Eurasian treecreeper overlaps with that of several other treecreepers, which can present local identification problems. In Europe, the Eurasian 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. A singing treecreeper is usually identifiable, since short-toed treecreeper has a distinctive series of evenly spaced notes sounding quite different from the song of Eurasian treecreeper; however, both species have been known to sing the other's song. Three Himalayan subspecies of Eurasian treecreeper are now sometimes given full species status as Hodgson's treecreeper, for example by BirdLife International, but if they are retained as subspecies of Eurasian, they have to be distinguished from three other South Asian treecreepers. The plain tail of Eurasian treecreeper differentiates it from bar-tailed treecreeper, which has a distinctive barred tail pattern, and its white throat is an obvious difference from brown-throated treecreeper. Rusty-flanked treecreeper is more difficult to separate from Eurasian, but has more contrasting cinnamon, rather than buff, flanks. The North American brown creeper has never been recorded in Europe, but an autumn vagrant would be difficult to identify, since it would not be singing, and the American species' call is much like that of Eurasian treecreeper. In appearance, brown creeper is more like short-toed than Eurasian, but a vagrant might still not be possible to identify with certainty given the similarities between the three species. Taxonomy The Eurasian treecreeper was first described under its current scientific name by Linnaeus in his Systema naturae in 1758. The binomial name is derived from Ancient Greek kerthios, a small tree-dwelling bird described by Aristotle and others, and Latin familiaris, familiar or common. This species is one of a group of very similar typical treecreeper species, all placed in the single genus Certhia. Eight species are currently recognised, in two evolutionary lineages: a Holarctic radiation, and a southern Asian group. The Holarctic group has a more warbling song, always (except in C. familiaris from China) starting or ending with a shrill . Species in the southern group, in contrast, have a faster-paced trill without the sound. All the species have distinctive vocalizations and some subspecies have been elevated to species on the basis of their