Date of Award

2021

Document Type

Open Access Master's Thesis

Degree Name

Master of Science in Forest Ecology and Management (MS)

Administrative Home Department

College of Forest Resources and Environmental Science

Advisor 1

Kristin E. Brzeski

Committee Member 1

Jared Wolfe

Committee Member 2

John Vucetich

Committee Member 3

Melissa Karlin

Abstract

Hybridization can be a conservation concern if genomic introgression leads to the loss of an endangered species’ unique genome, or when hybrid offspring are sterile or less fit then their parental species, but hybridization can also be an adaptive management tool if rare populations are severely inbred. One such species, the red wolf, is critically endangered in the United States, where all extant red wolves are descended from 14 founders which has contributed to an increase in inbreeding over time. Red wolves were considered extirpated from Texas in 1980, but before they disappeared, they hybridized with encroaching coyotes creating a hybrid population. In 2018, a genetic study identified individuals on Galveston Island, Texas with significant amounts of red wolf ancestry. We returned to Galveston for a more in-depth analysis of this hybrid population to identify the extent of red wolf ancestry in the population and mechanisms that support it on the landscape. We identified 23 individuals from Galveston Island and 8 from mainland Texas with greater than 10% red wolf ancestry. Two of those from mainland Texas had greater than 50% red wolf ancestry estimates. Additionally, this population had 6 private alleles that were absent in all North America reference canid populations, possibly representing lost red wolf genetic variation. We additionally identified several individuals on Galveston Island and the mainland of Texas that retained a unique red wolf mitochondrial haplotype. Our results confirm the presence of substantial red wolf ancestry persisting on Galveston Island and mainland Texas. This population has the potential to benefit red wolf conservation through novel reproductive techniques and ultimately through de-introgression strategies, with the goals of recovering extinct red wolf variation and reducing inbreeding within the species.

Available for download on Wednesday, December 07, 2022

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