Variability of response of the corn bunting, Emberiza calandra, to songs of different dialects

Experiments on the corn bunting were carried out in two localities of different dialects. In the center of the territory of each bird, we played two natural songs: either one local song and one song of the foreign dialect or two local songs coming from a neighbor and from a non-neighboring individual. The following results were obtained: (1) The behavioral responses are always more intense to the local song than to the song of a foreign dialect. Thus, the behavior of the corn bunting is similar to that of species with dialects studied up to now. (2) Eighty percent of the birds tested with the song of the foreign dialect react weakly or not at all. This peculiarity, which is specific to the corn bunting, suggests limited possibilities of generalization in this species. (3) The behavioral responses to the songs of a neighbor and of a non-neighboring individual of the same locality, are aggressive and of the same intensity. This means that the song of a neighbor, emitted from a different place than usual, is perceived by the bird as a threat to its territory.