GEOGRAPHIC SONG VARIATION AND ITS CONSEQUENCES IN THE GOLDEN BOWERBIRD

Geographic variation in birdsong is known from a variety of taxa, but is especially common and most frequently reported in passerines with resource-based territorial mating systems. To date, relatively little data have been presented on patterns of song variation in species with lek and leklike mating systems. In this paper, we describe geographic song variation in the Golden Bowerbird (Prionodura newtonia) a species with a leklike mating system. We compared recordings of the species advertisement song, collected from five isolated forest blocks from across the species range in northeastern Australia. Golden Bowerbird advertisement song shows marked geographic variation in form. All males within a population sing a song similar to each other, but distinct from that of males from other locations. The song traits important in discriminating between the songs of the different populations were bandwidth, number of peaks, dominant frequency, fundamental frequency, internote interval, and pureness. Discriminant function analyses based on these traits were highly accurate in assigning songs to their population of origin. We then used playback experiments to test whether geographic song variation in Golden Bowerbirds is functional. In the playback experiments males responded more strongly to song from local dialects than from foreign dialects. We discuss our results in light of current hypotheses on the evolution of geographic song variation. Variación Geográfica del Canto y Sus Consecuencias en Prionodura newtonia Resumen. La variación geográfica del canto de las aves es conocida para muchos taxa, pero es especialmente común en paserinos con sistemas reproductivos territoriales basados en la disponibilidad de recursos. Hasta ahora, se han presentado relativamente pocos datos sobre la variación del canto en especies con un sistema reproductivo con asambleas de cortejo (lek) y con sistemas reproductivos similares al tipo lek. En este trabajo, describimos las variaciones geográficas del canto de Prionodura newtonia, una especie que presenta un sistema reproductivo del tipo lek. Comparamos grabaciones de los cantos de anuncio, colectados en cinco bosques aislados a lo largo del rango geográfico de la especie en el noreste de Australia. El canto de anuncio de P. newtonia mostró una marcada variación geográfica en cuanto a la forma. Todos los machos pertenecientes a una misma población cantaron de forma similar entre ellos, pero difirieron de machos pertenecientes a ot