Date of Award

8-2014

Degree Type

Masters Thesis

Degree Name

Master of Arts (MA)

Department

Psychology

Committee Chair

Stan Kuczaj

Committee Chair Department

Psychology

Committee Member 2

Alan Hajnal

Committee Member 2 Department

Psychology

Committee Member 3

Holli Eskelinen

Abstract

The manner in which dolphin calves acquire their whistle repertoire is largely unknown. This paper focuses on whistle development in four bottlenose dolphin calves during the first thirty days of life in order to increase our understanding of the early emergence of whistles and whistle-like vocalizations. The acoustic parameters of whistle-type vocalizations (i.e., whistles and whistlesquawks) that coincided with a bubblestream emission from the focal calf and/or its mother were analyzed, as were the behavioral states of the mother-calf pair during the emission of such vocals. Mother and calf whistle rates are inversely related, with the mother whistling more often in the first ten days of the calf’s life, and the calf whistling most often in the third ten days. Maternal whistles are most common when the calf and mother are less than one meter apart whereas the calf whistles are likely to occur when the calf is greater than one meter away from the mother. Only one of the four calves showed a generally stereotyped whistle contour in the first thirty days (day 27), a whistle that has the “tremulous and quavery” quality commonly attributed to young calf whistles (Caldwell & Caldwell, 1979). Whistle-squawks are much more common than adult-like, clear narrowband whistles throughout this developmental period. The maximum frequency, frequency range, and duration of calf whistles and whistle squawks increase with age, suggesting that the acoustic prowess of dolphin calves develops during the first month of life.

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