Troglodytes troglodytes
Unmistakable. Very small, mouselike bird with short rounded wings, short neck and upright tail. Upperparts chestnut brown and finely barred. Underparts light buff. Forages in thick undergrowth and low bushes, crevices and holes for insects. Easily overlooked, but betrays its presence by its big voice. One of the smallest bird in northern Europe.
Song surprisingly loud. A high-pitched stream of clear notes resembling Robin and Dunnock in timbre. Differs from those in showing frequent shifts in pitch with much larger register than Dunnock, and by the unique, numerous, interspersed long trills. Warning call a short hard "teck", like banging two rocks together. Often repeated in series when excited to form machine-gun-like "firing".
Wikipedia: map (se also Xeno-canto below)
Birdlife ecology
