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Status and Trends of North American Bats Summer Occupancy Analysis 2010-2019 Data Release

February 22, 2022

This data release contains the results from the North American Bat Monitoring Program's report titled 'Status and Trends of North American Bats Summer Occupancy Analysis 2010-2019'. Specifically, these data include tabular data and geospatial data for the species-specific results related to the status and trends of 12 bat species at multiple spatial scales including: 10 km x 10 km grid cells, state/province/territories, and range-wide across the geographic extent of monitoring data for each species (i.e., across 'modeled species ranges'). They were produced using an analytical pipeline supported by web-based infrastructure for integrating continental scale bat monitoring data (stationary acoustic, mobile acoustic, and capture records) to assess the summer (May 1-Aug 31) population status and trends of North American bat species across their modeled ranges at multiple spatial scales. An occupancy model was estimated for each species while accounting for biases from false positives (i.e., misclassification error) and false negatives (i.e., detectability). Then, using the estimated relationships between grid cell occupancy probabilities for each species with ecological and spatiotemporal predictors, maps of species occupancy probabilities were produced for each year of sampling, for each NABat grid cell in each species' 'modeled range'. Finally, status and trends indicators across larger spatial extents (e.g. range-wide, state/territory/province) were derived based on the grid cell level occupancy probabilities over time.

A tabular file is included for each species detailing the occupancy probability predictions of each 10 km x 10 km grid cell in each modeled species range, with predictions (means, and the 95% credible intervals) for every year of monitoring data. Next, a geospatial layer is provided that contains the merged NABat Master Sampling Grid (i.e., the union of sampling frames for Continental United States and Canada + Alaska ) with a unique grid cell identifier ('grts') to allow joining the tabular estimates to the NABat grid cells. This geospatial layer can assist grid cell level visualizations of species occupancy probability distributions over time, and also includes grid cell level occupancy covariates used in these analyses. Additional results include a tabular file that contains the range-wide and regional estimates of species status and trend including: the mean grid cell occupancy probability across each larger spatial extent (e.g., modeled species range, states/territories/provinces) for every species and year of species monitoring data analyzed. Two additional trend indicators for species occupancy (the average annual change rate, and the total change rate) were included in the same file, across several time frames including 3 years of change (and 4 years of monitoring data from 2016 - 2019) and where possible, also over 7 years of change (8 years of monitoring data from 2012 - 2019) and 9 years of change (10 years of monitoring data from 2010 - 2019).