This guide is based on wikipedia's list of birds of Germany with accidentals removed to keep the guide under 500 entries.
The Long-tailed Tit or Long-tailed Bushtit (Aegithalos caudatus) is a common bird found throughout Europe and Asia. There are several extensive accounts of this species, most notably Cramp and Perrins, 1993; Gaston, 1973; and Harrap and Quinn, 1996. The majority of relevant research has been directed at its social and breeding behaviour.