UC Riverside

Here I examine vocal learning in the Costa’s hummingbird. I used the standard isolation experiment technique utilized for decades to study vocal learning in songbirds. Young male Costa’s hummingbirds were raised in isolation, with playback of adult song, and with playback in the presence of an adult model. All bird vocalizations were recorded to examine song ontogeny. I found that the necessary conditions required for vocal learning of a tutor song to take place in a lab setting included the presence of an adult model during tutoring and the tutor song must be Costa’s like. I developed a timeline of song ontogeny events including information about the onset of singing, and the stages of song development. Another experiment examined the timing of the sensitive phase by tutoring Costa’s for 20 hours in one of three different 30-day tutoring periods: Early (35-65 days post hatch (dph)), Mid (75-105 dph), and Late (115-145 dph). Results indicated that Costa’s can learn some vocal information across all three tutoring periods but that the amount of tutoring during one tutoring period was insufficient for production of normal Costa’s song. Finally, I examined open-ended vocal learning by exposing previously isolated birds to other Costa’s hummingbirds and found that songs change after exposure, even after two years of isolation.