Animal Behavior & CognitionAnimal BehaviourPeer-reviewed
Geographic variation in the songs of two closely related song-learning species, Anna's and Costa's hummingbird (Calypte anna, C. costae)
Ayala N. Berger, Wendy Y. Ye, Trinh Kondo…·Polly Campbell A
This study examines geographic variation in songs of two hummingbird species, finding that Anna's hummingbirds show population-level song variation while Costa's hummingbirds show minor frequency differences.