Department or Program

Biology

Abstract

Bowhead whales (Balaena mysticetus) in the Bering-Chukchi-Beaufort (BCB) population are defined by their residence in and migrations between wintering grounds in the Bering Sea and summering grounds in the Beaufort Sea. The regular passage of the majority of the population along the coastline of northern Alaska invites the possibility of answering several questions regarding bowhead song. Marine autonomous recording units were deployed in the Chukchi Sea near Point Barrow, Alaska and recorded approximately 1200 hours of continuous audio from 12 April to 27 May 2011. We identified 12 unique song types from approximately 95 hours of singing and characterized them quantitatively based on unit order, frequency and duration. This represents the greatest number of songs ever documented during the spring for this population. General song structure was consistent with earlier descriptions, but none of our song types were previously reported. The repetition of 5 song types over the course of the season composed 86% of the total duration of recorded song. This suggests a shared song repertoire between individuals. Singing behavior was highly organized as we documented only two instances of overlapping songs despite the passage of hundreds of whales. Total song duration was not influenced by whale abundance or by time of day, although several songs were exclusively recorded during the day (0600-1800) or at night (1800-0600). Singing during early-mid spring, when breeding occurs, supports the common mysticete theory that song plays a role in reproduction, but further study is necessary to draw conclusions regarding the function of song.

Level of Access

Restricted: Embargoed [Open Access After Expiration]

First Advisor

Ambrose, William

Date of Graduation

5-2013

Degree Name

Bachelor of Science

Number of Pages

47

Components of Thesis

1 pdf file

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