In partial fulfillment of the requirements for the degree of
Master of Science in Biology
in the
School of Biological Sciences
Emily Skibinski
Will defend her thesis
“Testing Darwin's Naturalization Hypothesis and Elton's Bio-Resistance Hypothesis in North American Breeding Birds”
1st, April, 2024
12 PM, EBB 4029
https://gatech.zoom.us/j/95409236044
Thesis Advisor:
Dr. Lin Jiang
School of Biological Sciences
Georgia Institute of Technology
Committee Members:
Dr. Benjamin Freeman
School of Biological Sciences
Georgia Institute of Technology
Dr. Katie Stumpf
School of Biological and Environmental Sciences
Georgia College and State University
Abstract: Invasive species cause environmental and ecological havoc, so it is of great importance to understand why and how they naturalize. Two influential hypotheses have long been at the center of debate around invasive species success: Darwin's naturalization hypothesis; which states that invaders which are less closely related to natives will be more successful, and Elton's bio-resistance hypothesis; which states that communities with higher levels of biodiversity will be more difficult to invade. Many studies have been conducted to test these hypotheses, to mixed results. However, studies which examine these hypotheses through the lens of functional traits and functional diversity are rare. I use data from the Breeding Bird Survey (BBS) to analyze if the native functional diversity has any effect on the non-natives, and if the difference between native and non-native traits is larger, or smaller than expected by chance. I found that what affects the non-native species is extremely variable depending on multiple factors such as non-native metric used, or native functional diversity metric used. Additionally, which non-native traits are more or less similar to the natives is variable, depending on which trait is being compared. Overall, this study highlights several issues in the literature which tries to solve Darwin’s conundrum and the invasion paradox: what metrics are used to answer these questions matters a great deal, and more examinations of how these hypotheses relate to functional diversity and functional traits needs to be carefully examined further.