Habitat Selection by Meadow Voles (Microtus Pennsylvanicus) and Schrews (Sorex spp.) in Sedge Meadows and Use of Remote Cameras to Analyze Behavior in Meadow Voles and Meadow Jumping Mice (Zapus hudsonius)

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Date
2016-01Author
DeBolt, Adam E.
Publisher
University of Wisconsin-Stevens Point, College of Natural Resources
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Small mammals play a variety of important roles in Wisconsin ecosystems. Small mammals act as seed dispersers and seed predators, as well as a valuable food source for a variety of predators. An abundance and rich diversity of small mammals could indicate a healthy ecosystem, especially in restored sites.
We studied four sedge meadows in central Wisconsin: Moses Creek, Lost Creek, George Mead Wildlife Area (George Mead), and the Green Circle Trail (GCT). Two of these sites were recently restored and two of these sites are natural sedge meadows. The first objective for this study was to determine the habitat selection of meadow voles (Microtus pennsylvanicus) and shrews (Sorex spp). Our second objective was to determine if there was a difference in number of male and female meadow voles captured. The third objective was to determine if there was a significant difference in percent time exhibiting vigilant, feeding, and investigative behavior between meadow voles and meadow jumping mice (Zapus hudsonius).
During 2014, 40 Sherman live traps were placed on two grids at Moses Creek, Lost Creek, and George Mead. Ten traps were placed at the Green Circle Trail site because it was a smaller area. We had 960 trap nights at Moses Creek, 840 trap nights at Lost Creek, 840 trap nights at George Mead, and 192 trap nights at the Green Circle Trail. We had 68 captures of small mammals at Moses Creek, 19 captures at Lost Creek, 6 at George Mead, and 8 at the Green Circle Trail, producing 7%, <1%, 2%, 4% and success rates, respectively. We ran logistic regressions and used Akaike’s Information Criteria (AIC) to determine habitat selection by meadow voles and shrews. The best model was distance to cover for the habitat selection of meadow voles and had an AICc value of 98.65, whereas the shrew AIC did not yield a significant model. Habitat selection of meadow voles seems to be influenced by the distance to thick
woody cover. Distance to woody cover would allow them the best cover to escape predators in an area where coarse woody debris is sparse.
Remote cameras were placed one meter above the ground at each study site during the field season. The cameras faced downwards and were active concurrently with trapping. Seed piles mixed with sand were placed under the cameras. The cameras recorded 572 usable photos and 298 usable videos. Meadow voles were identified in 364 photos, 87 photos had meadow jumping mice, 26 had an unknown individual, 1 photo had a short-tailed weasel (Mustela erminea), and 1 had a raccoon (Procyon lotor). Of the 298 videos, 218 showed meadow voles, 51 showed meadow jumping mice, 13 showed unknown species, 3 showed raccoons, and 1 showed a short-tailed weasel . Three Mann-Whitney U tests were run to determine difference in percent time exhibiting vigilant, feeding, and investigative behavior between meadow voles and jumping mice. Each test was significant (p < 0.05). Meadow voles likely spent more time showing vigilant behavior because they cannot escape predation as easily as bipedal meadow jumping mice. Mann-Whitney U tests were conducted for meadow vole behaviors by the time of day. A significant difference in percent time showing feeding behavior and vigilant behavior was apparent for meadow voles, depending on the time of day. Meadow voles spent more time on the seed piles at night, which could be due to predation concerns. Percent time exhibiting investigative behavior did not have a significant difference between daylight and night time videos.
Remote cameras can be an extremely useful for sampling small mammal populations. In areas where traps are considered invasive or if sensitive mammals are being studied, remote cameras are an alternative option.
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http://digital.library.wisc.edu/1793/81900Type
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