Research Overview

Evolution of Hummingbird Coloration and Courtship Displays

Hummingbirds showcase some of the most brilliant colors in the animal kingdom and possess almost every color under the rainbow. These colors are primarily iridescent meaning they are angle-dependent structurally based colors. The angle dependence of iridescent coloration allows hummingbirds to drastically change their perceived color through behavioral modifications of their position and orientation towards a receiver. I am working to understand how iridescent coloration interacts with behavioral displays and the environment in hummingbirds and how these two traits co-evolved. On my youtube channel, you can find examples of displays from the species below.

From left to right: Black-chinned (display), Broad-tailed (display), Allen’s (display), Calliope (display), Costa’s (display), and Anna’s hummingbirds (display).

Broad-Scale Patterns of Color Evolution

I am also working to understand how colors evolved in several groups of taxa. Color evolution can be influenced by several factors such as the mechanism of color production, natural selection pressures, or sexual selection. For example, I have found in wood-warblers that differences in coloration between males and females has been driven by the distances each species migrates. I am also working to understand the evolutionary pathways of carotenoid pigments (responsible for red, oranges, and yellows in most birds) in finches and the evolution of the huge diversity in hummingbird coloration.

Environmental Influences on Multiple Signals

The environment influences signals, such as coloration and behavioral displays, in many ways. In a tropical passerine, the red-throated ant-tanager, I am finding that both ambient noise and light on a male territory predict aspects of that male’s song and coloration. I am continuing to explore this relationship and also working to understand environmental influences on the function and perception of hummingbird visual signals.

Other Color-Based Research

Animals display a huge diversity in coloration, which can be seen in the variation found in the mechanisms of color production and the function of coloration. I am interested in studying coloration of all forms, and have started exploring the mechanisms and functions of colorful traits in peacocks, grasshoppers, beetles, Gila monsters, and penguins.

One thought on “Research Overview

  1. Pingback: About me | Richard K. Simpson

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