Date of Graduation

Fall 2013


Master of Science in Biology



Committee Chair

Lynn Robbins


Missouri bats, winter activity, Vespertilionidae, temperature, humidity, barometric pressure, Myotis grisescens, gray bat, white-nose syndrome

Subject Categories



The arrival of white-nose syndrome (WNS) has stimulated interest in winter bat activity. Data from a bat activity study in southern Missouri indicated winter gray bat (Myotis grisescens) activity above expected levels. Study objectives were to assess gray bat winter activity including investigating winter feeding, the need for water, whether winter activity occurs at caves and foraging areas, whether gray bats are more active relative to other species, and the effect of climate variables. Acoustic monitoring occurred over three winters at areas in Laclede, Shannon, and Washington counties Missouri, and captures occurred during the 2012-13 winter at Coffin Cave in Laclede County and Bat Cave in Shannon County. I collected temperature, humidity, and barometric pressure data at Coffin Cave and Bat Cave during 2012-13. Gray bats were captured on 24 of 26 attempts, at temperatures as low as -1.7oC. Of 350 bats captured, three provided a feeding fecal sample during mid-winter. Urinating was recorded in >50% of gray bats. Those at Coffin Cave, with available water, urinated earlier than at Bat Cave, with no available water. Acoustic data indicated that gray bats were active all winter at caves and foraging areas and at higher proportions than expected based on cave populations. Activity at Bat Cave correlated with inside humidity and outside temperature, while activity at Coffin Cave did not correlate with climate variables. Activity at Bat Cave was higher than at Coffin Cave. Water needs appear to drive activity.


© Joshua David Parris

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