Date of Award

May 2024

Degree Type

Thesis

Degree Name

Master of Science

Department

Biological Sciences

First Advisor

Emily Latch

Committee Members

Jeffrey Karron, Gretchen Meyer

Keywords

conservation, DNA Barcoding, Microtus, Species Identification

Abstract

Accurate species identification is necessary to implement conservation strategies in the wild. When traditional morphology-based species identification is challenging due to phenotypic plasticity, overlapping characteristics, or the species are otherwise cryptic, DNA-based species identification may be more suitable. Of the three species of Microtus in Wisconsin, two are listed as threatened at the state level. Both M. ochrogaster and M. pinetorum have stable population levels at the national level but are along the northern edge of their ranges in Wisconsin. Small and vulnerable populations of M. ochrogaster and M. pinetorum are limited to isolated patches in the southwestern portion of the state. A primary challenge in conservation efforts is the overlap in distribution and habitat with the third and more common species, the meadow vole (M. pennsylvanicus). The three species have similar morphology, but M. ochrogaster and M. pennsylvanicus are nearly identical morphologically. To distinguish between the three species in the field, biologists rely on overall appearance, however, small variations in an individual organism’s morphology can result in misidentification in the field. We evaluated two approaches for genetic species identification of the three species: a length polymorphism in the avrpr1a gene and novel, system-specific DNA barcoding in the COI gene. We evaluated methods using tissue and less invasive samples (fecal, whisker, and hair) that will minimize the need for handling animals in the field. A robust genetic species identification method will allow the Wisconsin Department of Natural Resources to gather accurate monitoring data and improve conservation efforts for M. ochrogaster and M. pinetorum. In addition, our approach to the development of system-specific DNA barcodes can be applied to similar systems that encounter challenges in morphology-based species identification.

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