High Quality Content by WIKIPEDIA articles! The Eurasian Treecreeper or Common Treecreeper (Certhia familiaris) is a small passerine bird also known in the British Isles, where it is the only living member of its genus, simply as Treecreeper. It is similar to other treecreepers, and has a curved bill, patterned brown upperparts, whitish underparts, and long stiff tail feathers which help it creep up tree trunks. It can be most easily distinguished from the similar Short-toed Treecreeper, which shares much of its European range, by its different song.