Date of Graduation

Summer 2016


Master of Science in Biology



Committee Chair

Lynn Robbins


Migration is an important and understudied aspect of the life histories of many species, particularly bats. Migration impacts conservation efforts, including efforts to manage the impacts of wildlife disease. The federally endangered gray bat (Myotis grisescens) is a migratory species with documented infections by Pseudogymnoascus destructans, the fungus that causes White-nose Syndrome (WNS). To better understand migration as it might relate to WNS, I quantified the timing and location of gray bat movements in Missouri using acoustic detectors and bat banding. I recorded calls at 4 maternity sites from January to May 2015, and used the R package PVAClone to generate estimates of r and K as measures of arrival rate and an index of population size at the maternity sites respectively. These values were plotted against each cave's distance from a major hibernaculum to examine whether there was an effect on the arrival of gray bats at a site. Values of r varied between 0.3 and 0.9, and values of K varied between 981 and 3020 among the maternity roosts: estimates were consistent whether considering observation error or not. While bats arrived at the closest maternity colony quicker and in greater numbers, the remaining rates and indices were equivocal with distance. Over 1,000 gray bats were banded and 18 were relocated, revealing previously undocumented connections between gray bat caves across the region. The acoustic methodology used in this thesis could be useful for management officials wanting to monitor the timing of bat migration and site activity, both of which could be affected by WNS. The cave network used by gray bats in Missouri could yield insight into how WNS spreads across cave networks.


gray bats, Myotis grisescens, migration, acoustic monitoring, bat banding

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© Cheyenne Leigh Gerdes

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