Graduation Date

Fall 2023

Document Type



Master of Science degree with a major in Biology

Committee Chair Name

Dr. Joseph Szewczak

Committee Chair Affiliation

HSU Faculty or Staff

Second Committee Member Name

Dr. Daniel Hayes

Second Committee Member Affiliation

Community Member or Outside Professional

Third Committee Member Name

Dr. Ho Yi Wan

Third Committee Member Affiliation

HSU Faculty or Staff

Fourth Committee Member Name

Dr. Karen Kiemnec-Tyburczy

Fourth Committee Member Affiliation

HSU Faculty or Staff

Fifth Committee Member Name

Dr. Devaughn Fraser

Fifth Committee Member Affiliation

Community Member or Outside Professional


Lasiurus, Borealis, Frantzii, Distribution, Sympatry, Eastern, Western, Red bat, Sequencing, Morphometrics, Pelage, lcWGS, Hybridization, Biogeography, Phylogenetics, Bat, Range, Genomics

Subject Categories



Several recent accounts of overlap and historic misidentifications regarding two species of the genus Lasiurus, Western red bat (Lasiurus frantzii) and Eastern red bat (Lasiurus borealis), have cast doubt on our understanding of their distribution, assumed spatial allopatry, and interactions in the United States Southwest. With the use of morphometrics and genetic sequencing, utilizing tissue collected from specimens throughout California and adjoining states, we have reassessed the current distribution, best practices for field identification, and genetic differentiation between both species. Appropriate species classification by region was achieved utilizing mitochondrial DNA, targeting the cytochrome c oxidase subunit I gene, and genetic discrepancies were assessed through lower coverage whole genome sequencing (lcWGS). All samples included morphometrics and pelage records to identify possible congruence in segregating the species phenotypically. We have confirmed L. borealis in four counties in southern California, one county in northern California, and 1 county in southern Arizona, displaying sympatry between both L. frantzii and L. borealis in the west. The lcWGS results verified the high level of divergence and genetic segregation between both species indicating little to no hybridization potential. No conclusive morphometric differentiation could be distinguished through physical metrics, but pelage has proven to have consistent discrepancies by region. The extent of L. borealis in the Western United States seems limited to the southern most areas of each state in the Southwest, but more sampling will be necessary to infer their true extent. The results acquired from this study strengthens our limited understanding of this dynamic group by inferring on their basic biology, their distinctive characteristics, and altogether aid in future conservation and research.

Citation Style

Journal of Wildlife



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