Marsh tit
Marsh tits are monogamous and often pair for life. Unlike many other tits, however, the marsh tit has a well-defined song and a wide song repertoire. Individual birds can have more than five songs, which they use interchangeably. Some of the more common songs include a typical tit-like, ringing, "schip-schip-schip-schip-ship", a more liquid "tu-tu-tu-tu-tu" and sometimes a sweet "tyeu-tyeu-tyeu-tyeu-tyeu".