The Functions of Song in Male House Wrens (Troglodytes Aedon)

Abstract

Abstract To assess the functions of song in male house wrens (Troglodytes aedon), we examined the pattern of song output during different stages of the breeding cycle and behaviour patterns of focal males and conspecifics that were associated with song. We recorded 2093.5 bouts of song from 11 different males in 12 breeding cycles during 3 years. Most song sung prior to pairing is sung at a high volume and is given spontaneously (i.e. is apparently not produced in response to the behaviour of any conspecific). Production of high volume spontaneous song ceased immediately for at least 7 days when the male paired, but resumed immediately upon loss of the mate. Paired males sang high volume spontaneous song after mates began incubating, and almost always sang this song within 10 m of an unoccupied nest site. Several males attracted second mates to these nest sites and immediately ceased their output of high volume spontaneous song. These observations strongly suggest that high volume spontaneous song functions in mate attraction. Male house wrens do not appear to use song on a routine basis to communicate with neighbours or other males. However, they do appear to direct song at other males when territories are threatened. Song is sung at intruders in the territory and at neighbours just establishing a territory of their own. Most song sung after pairing appears to be directed towards mates. We suspect than males use song to inform mates that there is no immediate threat of predation, allowing mates to move quickly to and from nest sites. We discuss the role and benefits of descriptive, correlative studies in assessing song function.