Skip to main
Lichen
George Mason University
Events

Upcoming Events

Apr 8

PhD Dissertation Defense - Environmental Science & Policy

Apr 8, 2026, 12:45 - 2:45 PM

Exploratory Hall Room 3301 and virtual on Zoom
Register for Zoom link here: https://tinyurl.com/3ku3m6pz

Apr 8

8 Apr (CLIM) Jiang, Cooling in the Equatorial Pacific

Apr 8, 2026, 1:30 - 2:30 PM

Apr 9

Dissertation Defense - Karen Holm, PhD Biosciences

Apr 9, 2026, 10:00 AM - 12:00 PM

View Calendar

PhD Dissertation Defense - Environmental Science & Policy

Apr 9, 2026, 11:00 AM - 1:00 PM

David King Hall Room 3006 and
Virtual on Zoom - please register:
https://tinyurl.com/y6bb7es9

PhD Dissertation
Department of Environmental Science and Policy
College of Science
George Mason University

 

Candidate: Juliana M. Villa
Defense Date and Time: April 9, 2026 at 11:00am
Defense Location: David King Hall Room 3006 and Virtual on Zoom
Title: Mechanisms of Eggshell Color Evolution in Avian Brood Parasites

Dissertation Director: Dr. Daniel Hanley
Committee: Dr. Virginia Abernathy, Dr. Rebecca Forkner, Dr. David Luther

 

ABSTRACT

 

Obligate avian brood parasites lay their eggs in the nests of other bird species, known as hosts. In defending against parasitism, hosts exert selective pressure on the appearance of these parasitic eggs. However, host selection remains relatively untapped when parasites interact with multiple host species. This dissertation aims to elucidate the role of local and regional host selection in shaping egg appearance in two model systems of avian brood parasitism: the common cuckoo and the brown-headed cowbird. Ultimately, this study investigates the multiple selective pathways that drive the evolution of parasitic egg appearance, from non-mimetic to imperfect and near-perfect mimicry.

 

* The programs and services offered by George Mason University are open to all who seek them. George Mason does not discriminate on the basis of race, color, religion, ethnic national origin (including shared ancestry and/or ethnic characteristics), sex, disability, military status (including veteran status), sexual orientation, gender identity, gender expression, age, marital status, pregnancy status, genetic information, or any other characteristic protected by law. After an initial review of its policies and practices, the university affirms its commitment to meet all federal mandates as articulated in federal law, as well as recent executive orders and federal agency directives.