Date of Award
2026-05-01
Degree Name
Master of Science
Department
Biological Sciences
Advisor(s)
Philip Lavretsky
Abstract
Hybrid zones provide unique opportunities to study morphological and ecological consequences of hybridization. While landscape genetic studies confirm a newly established contact zone between Mexican Ducks (Anas diazi) and Western Gulf Coast Mottled Ducks (Anas fulvigula maculatus), I provide the first quantitative morphological comparisons of the two taxa and their hybrids in Chapter 1. First, I report significant differences among parental species in lamellar density, body mass, tarsus length, and wing chord lengths, with hybrids exhibiting intermediate or backcross-aligned phenotypes. In contrast, measured bill dimensions did not differ significantly between parental taxa. Despite substantial overlap in bill morphology between Mexican and Western Gulf Coast Mottled Ducks, I apply targeted amplicon amplification coupled with Oxford Nanopore sequencing to characterize diets of these ducks in Chapter 2. Doing so revealed broadly similar diet compositions across taxa. I determined that models including genetic ancestry, geography, and seasonality best explained recovered diet diversity, which were expectedly dominated by plants and invertebrates. Among these, I recovered several uncommon diet items, particularly in individuals sampled from interior stock ponds. I posit that prey items may become available to ducks after rain events that would otherwise not be, showcasing that Mexican Ducks, Western Gulf Coast Mottled Ducks, and their hybrids exemplify a generalist-like diet. In fact, I recovered statistically similar alpha and beta diversity metrices among all groups. Thus, I conclude that similar bill morphologies recovered in chapter 1 indeed translates to a lack of dietary structuring among these ducks, and that dietary variation best reflects spatial and seasonal factors rather than species-specific specialization.
Language
en
Provenance
Received from ProQuest
Copyright Date
2026-05
File Size
127 p.
File Format
application/pdf
Rights Holder
Vergie Miranda Musni
Recommended Citation
Musni, Vergie Miranda, "Morphological And Dietary Consequences Of Hybridization Between Mexican Ducks And Western Gulf Coast Mottled Ducks In A Human-Altered Landscape" (2026). Open Access Theses & Dissertations. 4742.
https://scholarworks.utep.edu/open_etd/4742