Texas

Background
Hybridization can be a conservation concern if genomic introgression leads to the loss of an endangeredspecies’ unique genome, or when hybrid offspring are sterile or less t than their parental species. Yet hybridization can also be an adaptive management tool if rare populations are inbred and have reduced genetic variation, and there is the opportunity to enhance genetic variation through hybridization. The redwolf (Canis rufus) is a critically endangered wolf endemic to the eastern United States, where all extantred wolves are descended from 14 founders which has led to elevated levels of inbreeding over time. Redwolves were considered extirpated from the wild by 1980, but before they disappeared, they interbred withencroaching coyotes creating a genetically admixed population of canids along coastal Texas and
Louisiana. In 2018, a genetic study identied individuals on Galveston Island, Texas with signicant amounts of red wolf ancestry. We collected 214 samples from Galveston for a more in-depth analysis of this population to identify the amount of red wolf ancestry present and potential mechanisms that support retention of red wolf ancestry on the landscape.
Results
We identied 23 individual coyotes from Galveston Island and 8 from mainland Texas with greater than10% red wolf ancestry. Two of those individuals from mainland Texas had greater than 50% red wolfancestry estimates. Additionally, this population had 6 private alleles that were absent in the North America reference canid populations used in this study, which included 107 southeastern coyotes, 19 captive red wolves, and 38 gray wolves, possibly representing lost red wolf genetic variation. We also identifed several individuals on Galveston Island and the mainland of Texas that retained a unique red wolf mitochondrial haplotype present in the red wolf founding population. On Galveston Island, we identified a minimum of four family groups and found coyotes on the island to be highly related, but not genetically depauperate. We did not nd clear associations between red wolf ancestry estimates and landscape features, such as open green space or developed areas.
Conclusion
Our results conrm the presence of substantial red wolf ancestry persisting on Galveston Island andadjacent mainland Texas. This population has the potential to benet future red wolf conservation efforts through novel reproductive techniques and possibly through de-introgression strategies, with the goals ofrecovering extinct red wolf genetic variation and reducing inbreeding within the species.