GEOGRAPHIC-VARIATION IN SONG OF GAMBELS WHITE-CROWNED SPARROW

White-crowned sparrow (Zonotrichia leucophrys) song varies geographica lly, often forming local 'dialects' in sedentary and short-distance mi gratory subspecies. In playback experiments males and females can dist inguish this variation. Gambel's white-crowned sparrow (Z. l. gambelii ) is a long-distance migrant that breeds across subarctic Canada and A laska. Previous studies identified a wide degree of song variation wit hin local populations of this subspecies. I compared songs recorded in Alaska and Churchill, Manitoba, and found significant differences in acoustic structure. As in other subspecies, the most prominent differe nces occurred in the terminal trill portion of the song. In a playback experiment to territorial males at Churchill, males gave equivalent s trong responses to both Alaska and local gambelii song, significantly weaker responses to mountain white-crowned sparrow (Z. l. oriantha) so ng, and the weakest responses to heterospecific song. I describe a mod el of song recognition in which 'dialect recognition' is a component o f species recognition. I conclude that as a consequence of differences in the timing of song learning, the subspecies of white-crowned sparr ow may differ in the acoustic features that they attend to in song rec ognition. The diversity of song types at a local level within gambelii populations may interfere with recognizing song differences between p opulations.