Does boat activity influence the acoustic structure of humpback whale songs?

• Main Author: Heller, Briana J.
• Format: Text
• Language: unknown
• Published: UVM ScholarWorks 2021
• Subjects: Antarc*; Antarctica; Humpback Whale
• Online Access: https://scholarworks.uvm.edu/src/2021/biologicalsciences/4

Every year during their breeding season, southern humpback whales migrate from the Antarctica Peninsula and Chile to the tropical waters of Central America. This migration has attracted whale-watching activity in the region. Small vessels, such as whale-watching boats, emit broadband frequency noise that brings about a potential for masking the singing males. To attract mates, male humpback whales will perform songs of varying complexity and duration. Due to the covid-19 pandemic, there has been less tourism in Costa Rica and less boat activity overall. For this experiment, we studied the effects of boat activity on the song complexity of humpback whales outside of Cano Island Biological Reserve, Costa Rica. We theorized that with less boat activity during the pandemic, the recordings in 2020 would have more complex songs. To measure complexity, we compared several frequency and time variables. By comparing the complexity of the songs between the two years, we can observe if the whales are simplifying otherwise complex songs or singing at lower frequencies because of the presence of boats. The results from this study can aid government officials with enforcing regulation on tour-boat fleets.