Date of Award

2-22-2024

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

School of Biological Sciences

First Advisor

Matthew Dugas

Abstract

Young animals often solicit care from their parents using behaviors and morphologies collectively termed begging, and for many nestling birds these begging displays include presenting their parents with vividly colored mouthparts. Mouth color is a complex trait that varies both across and within species, and different aspects of color may be under independent selection and serve different functions; the two primary proposed explanations for the evolution of mouth color are to increase nestling conspicuousness to parents and to provide parents with information about nestling quality. In addition to signals like mouth color, parents could also directly assess traits like nestling body size to obtain information about the relative value of their offspring. Understanding how selection acts on different aspects of color and how parents respond to both color and size is complicated by the fact that different aspects of color covary in natural mouth tissue, and some aspects of color can also be associated with nestling size. My work with the house sparrow (Passer domesticus) uses a combination of mouth color manipulations and observational work, paired with measurement of parental provisioning, to ask what selective pressures influence the evolution of different aspects of color and to disentangle parental response to body size vs mouth color.

Comments

Imported from Border_ilstu_0092E_12546.pdf

DOI

https://doi.org/10.30707/ETD2024.20240618063947977453.999991

Page Count

96

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