Degree
Doctor of Philosophy (PhD)
Department
Biology
Document Type
Dissertation
Abstract
In this dissertation, I studied the color phenotypes of Lepidothrix, a genus characterized by colorful plumage patches including green, black, super black, yellow, oranges, and a range of blue shades. Birds have an impressive variety of mechanisms that produce these colors, and I investigated aspects of these three mechanisms in three chapters.
In Chapter 2, I examined the occurrence of and mechanisms creating super black plumage in the genus Lepidothrix. I collected reflectance measurements from 80 skins of eight Lepidothrix taxa having black plumage, and I used scanning electron microscopy to measure barbule width of 64 feathers of specimens with black, super black, and green plumage. My results showed super black plumage is more prevalent than previously recorded in Lepidothrix and that barbule width is associated with the production of super black color.
In Chapter 3, I studied the diversity of structures producing blue crown feathers in different species of Lepidothrix. I collected reflectance measurements from the crowns of 251 adult males in six Lepidothrix taxa and analyzed micro- and nanostructures in the barbs of Lepidothrix feathers to determine how changes in structure are related to changes in color. My results showed that the size and ratio of some color-producing structures affect the hue and saturation of light reflected by blue feathers. I also found that variation in the position and density of barbules on feathers affects the brightness of blue patches.
Finally, in Chapter 4, I used a whole genome resequencing dataset to investigate the genomic basis of two phenotypic traits in a hybrid zone between L. c. coronata and L. c. caelestipileata. The two subspecies differ in the color of their body plumage, black in L. c. coronata and green in L. c. caelestipileata, and in shades of blue on their crowns. The difference between black and green in body plumage is likely governed by the higher production of eumelanin in black relative to green plumage, whereas the blue in crowns is a structural color, and variation is created by changes in color-producing structures of feathers. My analyses identified several candidate genes that are potentially involved in producing the differences in both phenotypes.
Date
5-5-2025
Recommended Citation
Canton, Roberta, "PLUMAGE COLOR, FEATHER STRUCTURE, AND THE GENETICS OF COLOR IN LEPIDOTHRIX" (2025). LSU Doctoral Dissertations. 6798.
https://repository.lsu.edu/gradschool_dissertations/6798
Committee Chair
Faircloth, Brant