Behaviour 2019
Geographic variation in Anna’s hummingbird (Calypte anna) song.
Ayala N Berger, Polly Campbell, Chris J Clark. University of California, Riverside, Riverside, CA, United States

In species that learn their song, cultural transmission of song components can drive geographically distinct populations to form songs that vary from one another, resulting in the formation of dialects. Three avian clades are thought to have independently evolved song learning–parrots, oscine passerines, and hummingbirds–geographic variation has mainly been studied in passerines and to a lesser extent in hummingbirds. We extend the study of dialects to the bee hummingbird clade, focusing on Anna’s hummingbirds (Calypte anna). Anna’s hummingbirds are vocal learners with complex, three phrase, multi-syllable songs. Microgeographic variation and multiple syllable types have been found within one population. We recorded 6-24 males and 5-30 song iterations in each of five populations across the Western United States and tested for evidence of geographic variation in syllable structure, and in temporal and spectral components of song. This study will provide insight into song evolution in a non-passerine vocal learner, and will contribute to understanding of how complex signals evolve.