Date of Graduation

12-2023

Document Type

Dissertation

Degree Name

Doctor of Philosophy in Biology (PhD)

Degree Level

Graduate

Department

Biological Sciences

Advisor/Mentor

Westerman, Erica L.

Committee Member

DuRant, Sarah E.

Second Committee Member

Joshi, Neelendra K.

Third Committee Member

Lewis, Jeffrey A.

Keywords

Coloration; Community ecology; Development; Light environment; Phenotypic plasticity; Pollinators

Abstract

Phenotypic plasticity is a widespread mechanism that allows animals to respond quickly to seasonal changes in their environment. However, the depth and complexity of these plastic responses is still being discovered. One aspect of seasonal physiology that is relatively unstudied is changes to sensory physiology and how it may explain changes in behavior. To determine how changes in seasonal conditions affect behavior, coloration, and vision, I examined populations of wild butterflies in Northwest Arkansas. Focusing on a single species, the common buckeye Junonia coenia, I found that seasonal coloration covaries with thermoregulating behavior and is accompanied by changes in visual genes in eye tissue. Investigating seasonal response at the community level, I found that as light increases, abundance increases and behavior changes among butterflies, though individual butterfly families differ in their responses to seasonal conditions. Changes in season and temperature had a greater effect on abundance than behavior, which is also affected by shifts in weekly precipitation levels. Lastly, I described sexual dimorphism in eye size and coloration in potential visual signals in J. coenia. I found that females are brighter with more wing ornaments than males. Males have larger eyes than females despite being smaller in body size. Developing in shade causes a sexually dimorphic part of the wing to reflect more ultraviolet wavelengths, which are important for male mate choice in this species. Together these results demonstrate the important role the seasonal environment plays in shaping behavior and suggest covarying changes in coloration and visual physiology may underly seasonal behavioral shifts.

Available for download on Thursday, February 05, 2026

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