Translocation experiment
Two known hibernacula of persisting little brown bat (Myotis lucifugus ) colonies in New York and one hibernaculum previously extirpated of bats by white-nose syndrome (WNS) in Vermont were used in this study (Fig. 1). Prior to the beginning of the hibernation season, we installed ten, five-sided reptile cages (dimensions: 12”W, 18”L, 20”H; ZillaRules, Wisconsin, USA) in known or historical roosting locations within each site (Supplemental Fig. 7). Each cage was mounted so that the open side was in contact with the hibernaculum surface, allowing bats to roost directly on the substrate. Cages were mounted high on site ceilings and were sealed to prevent predation of bats. Poultry waterers were placed in each cage to provide a water source.
At the beginning of December 2018, in early hibernation, we returned to the two sites of persisting M. lucifugus colonies in New York. We collected 45 male M. lucifugus from each site and fitted them with a unique forearm band. Each individual was randomly assigned to both a site and a cage within that site with 3 individual bats from the same origin site sharing each cage. These assignments were in a full factorial design, such that of the 45 bats collected from each site, 15 were assigned to be caged within the same site, 15 to be caged within the opposite persisting site, and 15 to be caged in the previously extirpated site. We placed each bat individually in a cloth bag and transported them to their assigned site in a cooler so that they would remain in torpor and limit energy expenditure. We replicated the transportation disturbance across all treatment groups. Bats remained in their assigned cages for the duration of hibernation. All individuals were caged with at least one infected individual. In mid-hibernation, each of the three sites were visited once to record survival status through visual inspection (Persisting 1: 50 days; Persisting 2: 64 days; Extirpated: 71 days following initial translocation); no cages were opened or bats handled, as to minimize disturbance. In March 2019, in late hibernation, 110 days following the initial translocation, we returned to each of the three sites to collect data and terminate the experiment. We released all surviving individuals at their site of origin.