Big brown bat (Eptesicus fuscus) capture records before and after white-nose syndrome

We collated big brown bat capture records collected between March and October 1990–2020 from wildlife agencies and researchers in Georgia, Illinois, Indiana, Kentucky, Mississippi, New York, North Carolina, Ohio, Pennsylvania, Tennessee, and Virginia. We then paired this data with pathogen introduction and invasion information for Pseudogymnoascus destructans (fungal pathogen that causes white-nose syndrome and kills North American temperate bats). We used capture records that included date of capture, capture site name, sex (male/female), reproductive status (females only: non-reproductive/pregnant/lactating/post-lactating), age (adult/juvenile), mass (g) and forearm length (mm) at time of capture. Records that did not meet these minimal requirements were removed from the dataset. Site names were then masked due to the potential of exposing the location of sensitive species by labeling each site name by state and a unique identifier. We used data for adult big brown bat captures only. We also incorporated county of capture into the dataset. If county was provided, we used the reported county of capture. If latitude and longitude of capture were provided, we linked this point to the county level using the sp, maps and maptools packages in the statistical environment R. Once county was identified for each entry, we masked latitude and longitude to county by determining the latitude and longitude of the county centroid point using the housingData package in R. Into this dataset for big brown bat capture records, we added variables for the introduction and invasion of the bat fungal pathogen Pseudogymnoascus destructans (Pd). Year of Pd introduction was determined as the earliest year of confirmed or suspected Pd occurrence in each state using US Geological Survey data for Pd surveillance at whitenosesyndrome.org. We standardized Pd introduction across the dataset by subtracting the year of confirmed or suspected Pd occurence from the year of capture. Thus, the year of confirmed or suspected Pd occurrence in each state was at a baseline of '0', the number of years before Pd introduction were negative integers, and the number of years after Pd introduction were positive integers. We then created time-steps to represent groupings for disease exposure at the time of capture: pre-Pd invasion (< 0 years), Pd invasion (0–1 years), Pd epidemic (2–4 years) and Pd establishment (5 + years).