title: Effects of white-nose syndrome on regional population patterns of 3 hibernating bat species.
abstract: Hibernating bats have undergone severe recent declines across the eastern United States, but the cause of these regional-scale declines has not been systematically evaluated. We assessed the influence of white-nose syndrome (an emerging bat disease caused by the fungus Pseudogymnoascus destructans, formerly Geomyces destructans) on large-scale, long-term population patterns in the little brown myotis (Myotis lucifugus), the northern myotis (Myotis septentrionalis), and the tricolored bat (Perimyotis subflavus). We modeled population trajectories for each species on the basis of an extensive data set of winter hibernacula counts of more than 1 million individual bats from a 4-state region over 13 years and with data on locations of hibernacula and first detections of white-nose syndrome at each hibernaculum. We used generalized additive mixed models to determine population change relative to expectations, that is, how population trajectories differed with a colony's infection status, how trajectories differed with distance from the point of introduction of white-nose syndrome, and whether declines were concordant with first local observation of the disease. Population trajectories in all species met at least one of the 3 expectations, but none met all 3. Our results suggest, therefore, that white-nose syndrome has affected regional populations differently than was previously understood and has not been the sole cause of declines. Specifically, our results suggest that in some areas and species, threats other than white-nose syndrome are also contributing to population declines, declines linked to white-nose syndrome have spread across large geographic areas with unexpected speed, and the disease or other threats led to declines in bat populations for years prior to disease detection. Effective conservation will require further research to mitigate impacts of white-nose syndrome, renewed attention to other threats to bats, and improved surveillance efforts to ensure early detection of white-nose syndrome.
authors.affiliation: National Institute for Mathematical and Biological Synthesis, Claxton Building, 1122 Volunteer Boulevard, Suite 106, University of Tennessee, Knoxville, TN, 37996-3410, U.S.A.. tomingersoll@yahoo.com.
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Ingersoll
authors.affiliation: Department of Biology, Temple University, 1900 North 12th Street, Philadelphia, PA, 19122, U.S.A.. bjsewall@temple.edu.
authors.forename: Brent J
authors.initials: BJ
authors.lastname: Sewall
authors.affiliation: Northern Research Station, U.S. Forest Service, University of Missouri, Columbia, MO, 65211, U.S.A.
authors.forename: Sybill K
authors.initials: SK
authors.lastname: Amelon
mesh_terms: D000820:Animal Diseases; D000818:Animals; D001203:Ascomycota; D002685:Chiroptera; D003247:Conservation of Natural Resources; D006605:Hibernation; D009181:Mycoses / Q000662:veterinary*; D009666:Nose; D011157:Population Dynamics; D012621:Seasons
keywords: Myotis lucifigus; Myotis lucifugus; Myotis septentrionalis; Perimyotis subflavus; Pseudogymnoascus destructans; emerging infectious disease of wildlife; enfermedades infecciosas emergentes de la vida silvestre; generalized additive mixed models; modelos aditivos mixtos generalizados; monitoreo de poblaciones; population monitoring