North American Bat Monitoring Program: Alberta 2018 Final Report
Executive Summary for the Final Report
Nine species of bat occur in Alberta with at least five species considered to be susceptible to population decline due to either disease (white-nose syndrome; WNS) or fatalities at wind energy facilities. Since 2015 Alberta has been a part of the North American Bat Monitoring Program (NABat) to gather data on current provincial bat distributions and relative abundances, predominantly through passive and mobile acoustic surveys. In 2018 15 NABat grid cells were acoustically surveyed, with 5 new grid cells surveyed (Peace and Red Deer North Saskatchewan Regions). Between one and four detectors surveyed each grid cell with a total of 276 nights of passive acoustic surveys and 13 nights of mobile acoustic surveys. For the passive surveys, sites were surveyed a mean of 18.4 nights (range of 5-30 nights). There were a total of 16,603 bat call sequences recorded during the passive surveys, with just over half (8509 or 52%) identified to species/species group. The majority (36%) of bat call sequences were identified as Lasiurus cinereus, followed by Myotis lucifugus (27%) and the Myotis 40k species group (17%). During the mobile surveys 306 bat call sequences were recorded, with over half (177 or 58%) identified to species / species group, predominantly attributed to the EPFU-LANO species group. The majority of the NABat passive acoustic surveys occurred prior to 1 July 2018 and mean nightly bat activity was highly variable, both in time and space. This was also the case when drilling down to identified species / species groups and detectors with some species having discrepancies in mean nightly activity between detectors within the same grid cell (Figures 6 through 20). At the provincial scale, generally bat activity was positively correlated with maximum nightly temperature, increasing distance to human footprint and vegetated types of human footprint. Bat activity was lower in all land cover types, compared to forest and decreased as the distance to roads increased, suggesting that bats use roads as travel corridors. Lastly, bat activity had a positive curvilinear relationship with distance to water suggesting that bats prefer the interface between water and vegetation but after a certain distance away from water bat activity drops. These findings have serious implications for the conservation and maintenance of Alberta’s bat populations with the increasing and emerging threats of WNS and wind energy development. In Alberta NABat surveys have been conducted in five of the six provincial Natural Regions. Future surveys should aim to fill gaps in the provincial distribution of surveys, particularly in the Parklands and Canadian Shield Natural Regions. As well, surveys should be concentrated in areas where populations are expected to decline, from either WNS (potential threat from south-west as WNS expands out from Washington State) or wind fatalities (wind belt of southern Alberta). Acoustic surveys have occurred between 1-4 times at each grid cell; once 2019 surveys are completed there will likely be data to start investigating provincial trends for potentially at-risk species, such as L. cinereus and M. lucifugus. In addition, continued searching for winter hibernaculum and maternity colonies of species susceptible to WNS should be a priority.