Date of Award


Document Type


Degree Name

Master of Science (MS)


College of Science and Mathematics



Thesis Sponsor/Dissertation Chair/Project Chair

John A. Smallwood

Committee Member

Lisa C. Hazard

Committee Member

Scott L. Kight


Using spectrographic analysis, I studied the vocalizations of American Kestrel (Falco sparverius) chicks to determine if siblings sounded more like each other than nonrelated chicks. I also performed a feasibility study on obtaining and analyzing vocalizations of wild adult kestrels. A total of 144 vocal recordings was obtained from 67 female and 77 male kestrel chicks in the 2005 and 2006 kestrel breeding seasons. Sixteen adult kestrel vocal samples were also obtained from eleven females and five males, each a parent to one of the broods that were audio-recorded.

Fifteen vocal parameters were analyzed through spectrographic analysis for each individual bird. Wilcoxon/Kruskal Wallis (Rank Sums) tests revealed that female vocalizations tended to have more harmonics than those of males. Principal Components Analysis of all fourteen other vocal parameters revealed no significant difference in male and female vocalizations. Analysis of variance (ANOVA) revealed a statistically significant correlation by brood on all but three of the fifteen vocal parameters, indicating that broodmates do sound more similar to each other than unrelated broods.

Since adult vocalizations had to be recorded from a distance (as they did not vocalize while being held), while chicks would vocalize as they were in the hand being banded, adult vocal recordings obtained were of a much lower quality and contained more background noise than those from the chicks. Since Note Duration, Number of Harmonics, and Internóte Distance were not affected by background noise, multivariate correlations were performed on these vocal parameters between adults and chicks. Sample sizes were too small to be analyzed for all adult male to offspring comparisons, as well as the comparison of adult females to their female offspring. Analysis of adult female vocalizations to those of their male offspring as well as to their brood as a whole revealed no significant correlations. I determined that it was not feasible to compare all aspects of the kestrel vocalizations recorded from different distances, as background noise removal did not work as well in vocalizations recorded from a greater distance.

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