CHANGES IN POPULATION SIZE OF BATS AT A HIBERNACULUM INALBERTA, CANADA, IN RELATION TO CAVE DISTURBANCE ANDACCESS RESTRICTIONS

摘要

Long-term data for bat populations are absent for much of North America, resulting in a generally poor understanding of bat population trends for the majority of species. Inventory of sedentary individuals at cave hibernacula offers one opportunity for long-term monitoring of bat populations. However, the Canadian Rockies have few known caves with large bat populations; thus, opportunities for assessing populations in these regions are limited. Where the majority of bats in Alberta, and most other areas in western North America, hibernate currently is unknown, but it is clear that known bat hibernacula in north-western North America account for a very small proportion of the total bat population (Schowalter 1979; Nagorsen and others 1993). Nonetheless, census data at cave hibernacula could provide a useful indicator of the general stability of bat populations, and are important for assessing the efficacy of cave management practices. With the rapid spread of white nose syndrome, a fungal pathogen spreading across North America that is associated with widespread mortality in populations of cave-hibernating bats (Blehert and others 2009), it is increasingly important to establish baseline population data prior to contact of bats with this pathogen or other unforeseen threats. In this note, we present 25 y of census data from Cadomin Cave, the largest known bat hibernaculum in Alberta, Canada.