Four decades of cultural evolution in House Finch songs

Bird song is the primary animal model system for cultural evolution. Longitudinal studies of bird song across many
generations can provide insights into patterns and mechanisms of change in socially transmitted traits. In this study, we
conducted a comparative analysis of songs of the House Finch (Haemorhous mexicanus) across an interval of 37 years
(in 1975 and in 2012). Recordings from both years were collected in western Long Island, New York, which is thought
to be the initial site of introduction of the House Finch around 1940 from the West Coast. Song types experienced
a complete turnover during this period, although half of the syllable types were represented in both samples. Song
length, frequency bandwidth and several other spectrographic features were the same in both years, and no structural
features predicted recurrence of individual syllables. Consistent with the fact that our study population expanded
substantially following a cultural founder effect, song and syll...