First Advisor

Lauryn Benedict

First Committee Member

Don Finan

Degree Name

Master of Science

Document Type

Thesis

Date Created

5-2026

Department

College of Natural and Health Sciences, Biological Sciences, Biological Sciences Student Work

Abstract

Vocal learning is rare among animals but is well developed in parrots, which can imitate novel sounds and, in captive settings, reproduce human speech. This study helps address a larger evolutionary question about vocal learning. Specifically, whether vocal learning ability is best understood as a single generalized trait or as a multi-dimensional system in which different acoustic features can be learned and reproduced with varying degrees of fidelity. This thesis quantifies how closely companion parrots match their human tutors across three acoustic dimensions (spectrographic structure, intensity contour, and pitch contour) and tests whether mimicry accuracy varies among individuals, differs between vowel and consonant phoneme types, and covaries with species-level average reported repertoire size. I analyzed paired recordings of parrots and their human tutors producing the same words or phrases. The dataset included 11 companion parrots across six species (Amazona aestiva, Melopsittacus undulatus, Nymphicus hollandicus, Psittacula krameri, Eclectus roratus, and Psittacus erithacus). Mimicry similarity was measured using spectrogram cross-correlation, pitch contour correlation, and intensity contour correlation.

Nonparametric analyses indicated substantial between-subject variation in spectrogram, pitch, and intensity similarity when phrase repetitions were treated as independent observations. Mixed-effects models that accounted for repeated phrases within each subject showed that phrase identity explained a large proportion of the variance, and a significant subject-level effect persisted for overall spectrographic similarity, while variability in pitch and intensity similarity did not have a significant relationship with subject identity. Vowel and consonant phoneme categories did not differ in spectrogram similarity in my sample. Species-level reported repertoire size was not significantly associated with subject-level median mimicry accuracy in spectrogram, pitch, or intensity domains, although spectrogram similarity did show a positive non-significant trend with repertoire size.

The data presented here support the idea that parrot vocal learning can be shaped by the demands of dynamic social environments, and that vocal mimicry ability is shaped by multiple interacting traits. Overall, these results report a multi-dimensional perspective on vocal mimicry in companion parrots where mimicry accuracy depends strongly on the individual, and different acoustic dimensions can be analyzed separately to learn more about different layers of mimicry accuracy, rather than forming a single overall “mimicry ability”.

Abstract Format

html

Disciplines

Ornithology

Keywords

Parrots; Vocal Learning; Bioacoustics; Mimicry

Language

English

Places

Greeley, Colorado

Extent

83 pages

Rights Statement

Copyright is held by the author.

Digital Origin

Born digital

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