An investigation of individual recognition by voice in female red-winged blackbirds

In order to determine if female Red-winged Blackbirds (Agelaius phoeniceus) recognize each other as individuals on the basis of voice alone, playback experiments with 31 resident female redwings were performed. Female redwings sing two distinct song types. Fifteen females were exposed to Type 1 neighbour and Type 1 non-neighbour songs, and 16 females were exposed to Type 2 neighbour and Type 2 non-neighbour songs. Based on matched-pairs comparisons of the females' behavioural responses to the playback songs, female redwings do not appear to distinguish each other individually by voice. Loudspeaker placeement may be one confounding variable of significant importance in auditory individual recognition experiments.