Publication Date

2026

Document Type

Dissertation/Thesis

First Advisor

Koop, Jennifer A.

Second Advisor

Fournier, Auriel

Degree Name

M.S. (Master of Science)

Legacy Department

Department of Biological Sciences

Abstract

The introduction of the invasive freshwater faucet snail (Bithynia tentaculata) and its associated parasites in the Upper Mississippi River and Great Lakes Region provides the opportunity to investigate how anthropogenic stressors impact the life history of lesser scaup (Aythya affinis) using the Mississippi Flyway. To understand the life histories and interactions between lesser scaup and faucet snails we examined historical records, research, and ecology textbooks. Our literature review identified critical knowledge gaps in lesser scaup literature surrounding population dynamics, reproduction, and migration. Specifically, the sub-lethal effects of invasive trematodes on the migratory behavior of lesser scaup in the Upper Mississippi River and Great Lakes Region is relatively unknown. To address this question, we surgically implanted 100 GPS/GMS intra-abdominal transmitters in hen lesser scaup captured at Navigational Pool 19 of the Mississippi River and Chautauqua National Wildlife Refuge in the Illinois River valley. Our results indicate that lesser scaup hens exposed to trematode infection migrated nearly 700 kilometers less than unexposed hens. Given this shorter distance traveled, exposed hens also arrived 8 days faster to their arrival location on the breeding grounds. However, this result was only marginally non-significant (p-value = 0.0588). We did not detect a significant difference between exposed and unexposed hens for Julian date of arrival and average migratory distance. Our results support that trematode infection have a negative effect on the migratory behavior of lesser scaup. Furthermore, our study provides evidence for increasing management and monitoring efforts within this region to improve habitat for migrating scaup. Future studies should investigate the sub-lethal effects of trematode infections on the reproductive behavior of scaup and whether it has a population level effect that is contributing to the decline in the continental population.

Extent

67 pages

Language

en

Publisher

Northern Illinois University

Rights Statement

In Copyright

Rights Statement 2

NIU theses are protected by copyright. They may be viewed from Huskie Commons for any purpose, but reproduction or distribution in any format is prohibited without the written permission of the authors.

Media Type

Text

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