A comparative and seasonal study was performed on trematode populations and communities within waterfowl definitive hosts in order to determine important factors in the structuring of these communities. Furthermore, larval trematode populations were also sampled in order to compare larval stages found within snail hosts to adult stages found within collected waterfowl in order to determine where infections could have occurred with the trematode species. 52 birds including 18 blue-winged teal (Anas discors), 5 bufflehead (Bucephala albeola), 4 common goldeneye (Bucephala clangula), 1 greater scaup (Aythya marila), 1 green-winged teal (Anas carolinensis), 11 lesser scaup (Aythya affinis), 1 northern pintail (Anas acuta), 1 redhead (Aythya americana), and 10 wood duck (Aix sponsa) were collected by licensed waterfowl hunters during the fall and spring migration seasons in 2012 and 2013, respectively. Of these species blue-winged teal, bufflehead, lesser scaup, and wood duck were sampled during the fall and spring migration. Overall, trematode populations and communities were highly variable among the hosts sampled and differences during the fall and spring migration season were also present, with the fall migration season harboring a greater number and diversity of trematodes.

In general, a total of 42,118 trematodes were recovered during the fall migration season, representing a total of 13 trematode species, whereas 316 trematodes were recovered during the spring migration, representing a total of 8 trematode species. The role of diet and overall size of the intestinal tract appeared to represent important factors in both the number of trematodes that were found as well as the species richness of trematodes. Overall, mean trematode intensity and species richness was highest in lesser scaup during the fall migration with wood duck harboring fewer trematodes and fewer trematode species than other birds used during community analysis (blue-winged teal and lesser scaup). When adult trematode communities were compared to larval trematode communities that were sampled, 2 trematode species (Cyathocotyle bushiensis and Sphaeridiotrema pseudoglobulus) appeared to have the ability to represent an autochthonous relationship, meaning that infections could have occurred at the site where both the birds and snails were collected. Although site characteristics could have played a role in the type and prevalence of certain types of trematodes found within the waterfowl hosts, host size (including length of the intestine), diet, and feeding patterns could also be important factors in determining the trematode species present within a given host and the number of trematodes within a given host. Finally, this work represents a comprehensive study on the trematode communities and populations of waterfowl trematodes found within Lake Winnibigoshish, Minnesota and the potential factors responsible for trematode distribution within intermediate and definitive hosts collected from this location.


Robert Sorenson

Committee Member

John Krenz

Committee Member

Timothy Secott

Date of Degree




Document Type



Master of Science (MS)


Biological Sciences


Science, Engineering and Technology

Creative Commons License

Creative Commons Attribution-NonCommercial 4.0 International License
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License



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