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Precipitation and acoustic monitoring results associated with Arizona 1 and Pinenut uranium mines collected 2015-2016

August 3, 2020

Acoustic monitoring stations were comprised of Wildlife Acoustics SMBAT2+ bat detectors powered by a 6v 36 AH (Powersonic, Model PS-6062NB) external battery and charged by a 6v solar panel (Brunton Solarflat) with a 6/12 voltage regulator (Rogue Engineering Inc.). Detectors were programmed to turn on at 1800 hours and monitor continuously throughout the night when triggered automatically by echolocating bats. Detectors stopped recording at 0600 hours the following morning. In general, most data were recorded in a zero crossing file format to allow for larger volumes to be recorded nightly over time. Acoustic monitoring was conducted only at Pinenut (PNUT) and Arizona 1 (AZ1) uranium mines where impacts to detectors from grazing cattle was limited. Due to the chain-link perimeter fence of the mines, direct access to the containment ponds and placement of the acoustic detectors were hindered at each respective mining site. Although acoustic detectors were placed approximately 20 meters away from the water's edge, the large size of the ponds and allowable placement of detectors limited the potential for collecting maximum activity. Acoustic sampling occurred nightly from 1 April 2015 to 20 September 2016. Data were downloaded at least once a month and analyzed using Kaleidoscope (Wildlife Acoustics, Maynard, Massachusetts). Files that were considered noise (based on frequency, fragment of call file, and lack of structure or shape relative to an emitted bat call pulse) were removed from the analysis. Recordings with one more pulses were included as part of the data set to determine the level of habitat use at each of the uranium mines. Given the high volume of nightly data recorded during the sampling period (i.e., >one year), these data were analyzed only for general presence-absence of bats over time. In addition to acoustic data, precipitation (mm) data were recorded daily from rain gauge stations located at each respective mine during the same sampling period. These data were compared to number of acoustic calls recorded at each site to provide insight on possible effects of weather.