Date of Graduation

8-2023

Document Type

Thesis

Degree Name

Master of Science in Biology (MS)

Degree Level

Graduate

Department

Biological Sciences

Advisor/Mentor

Roberts, Caleb P.

Committee Member

Mortensen, Jennifer L.

Second Committee Member

Willson, John D.

Keywords

Avian influenza; Egyptain geese; Invasion ecology; Landscape ecology; Species Distribution Modeling; Waterfowl

Abstract

In an increasingly interconnected world, the ecological and financial cost of invasive species is expected to continue to climb through the movement of exotic biota. Understanding the driving forces behind how a species invades, what environments promote their establishment, and what impacts they are likely to have on the invaded environment are all critical for management. Waterfowl, order Anseriformes, are one such category of invasive species of concern due to their popularity of accidental introduction, ease of movement, and propensity to affect both terrestrial and aquatic ecosystems. The Egyptian Goose (Alopochen aegyptiaca) is a native to the African continent that spread and established itself as a damaging invasive species in Europe in the 1700s and is now an incipient invader in North America. Much is unknown about the future of the invasion of the Egyptian Goose in North America. Understanding habitat suitability of the species can help predict areas where the species may invade in the future and highlight regions of immediate management concern. Furthermore, understanding how previous invasive waterfowl have influenced North America and how the Egyptian Goose has interacted both in its established invaded range and its native range, can help predict what could occur with the incipient invasion. The goal of this work is to 1. Establish concerns about the Egyptian Goose invasion through a literature review of the current and historical impacts of invasive waterfowl in North America 2. Model the invasion of the Egyptian Goose. To establish the concerns about the Egyptian Goose invasion in North America, we performed a systematic literature review. We used the PRISMA 2010 guidelines for performing holistic and quality literature reviews as well as the ‘litsearchr’ package in R to improve the quality of search terms. Our results show that these species are significant reservoirs of multiple diseases, including Escherichia coli (E. coli), Avian Paramyxovirus-1 (Newcastle disease), and avian influenza. Additionally, we found considerable gaps in the literature; particularly, field studies of newer invasive species and direct interactions with native avifauna. We found key gaps where the Egyptian Goose could pose a novel threat to North American ecosystems. To understand the invasion of the Egyptian Goose, we utilized Species Distribution Modeling techniques through Random Forest Classified modeling in Google Earth Engine. The volume of historical and current distribution data from eBird, as well as the three distinct geographical locations, allowed for a robust test of adaptations of invading species. We found strong evidence to support the niche shift hypothesis for the Egyptian Goose. Suitable climate conditions strongly varied between continents with Africa and North America having similarly median annual temperatures (20.6oC and 20.7oC) while Europe had a significantly lower median annual temperature (11.0oC). Egyptian Geese showed increasing affinity for urban environments with invasion stage doubling from Africa to Europe and tripling from Africa to North America. The strength of the suitability of highly urbanized areas increasing with recency of arrival suggests that urban environments may be acting as foothold habitat for the Egyptian Geese.

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