Subspecies recognition and song learning in zebra finches

Abstract

The songs of captive Taeniopygia guttata guttata from Timor, T. g. castanotis from the Australian mainland and hybrid zebra finch males were analysed sonagraphically and the response of females was measured in playback experiments. Guttata and Castanotis young were either raised normally by members of their own subspecies or cross-fostered to members of the other subspecies. Hybrid young were raised by Guttata male-Castanotis female pairs. Guttata songs were significantly longer than Castanotis songs, with more elements per phrase, and were sung at a higher frequency, irrespective of whether males had been raised normally or cross-fostered. Hybrid songs were intermediate between Guttata and Castanotis songs. The results suggest that rearing experience has little, if any, effect on these macrostructural differences between the songs of the two subspecies. Females implanted with oestradiol preferred songs of males of their foster-father subspecies, irrespective of whether these males had been cross-fostered or raised normally, indicating that females use macrostructural song features for subspecies recognition and that their song preferences are learnt. It is suggested that these macrostructural differences in song function in subspecies recognition.