When the Coeur d’Alene Mines’ Rochester operation in Nevada targeted the Nevada Packard silver-mining district for development, it discovered about 110 Townsend’s big-eared bats (Corynorhinus townsendii) roosting in the complex of abandoned mine workings. Though it was not required to do so, Coeur Rochester, under the leadership of Environmental Manager Jerry Hepworth, invested more than $110,000 over three years to rescue these bats and find new, improved homes for them. Along the way, the company developed what it hopes will be a carefully documented model for future relocations of the species.
For its extraordinary efforts to protect these bats and improve scientific knowledge about their habitat needs, Bat Conservation International honors Coeur Rochester as its 2003 Corporate Conservationist of the Year.
Nevada Packard was mined intermittently from the 1890s to 1970s, work that left about 150 openings in the area where Coeur Rochester identified a commercially viable orebody. Upon discovering that Townsend’s big-eared bats were using the old workings as seasonal habitat, Rochester decided to “redefine the state of the art” in reclamation of abandoned mines. The company teamed with University of New Mexico Professors William L. Gannon and Richard E. Sherwin (a former BCI Scholar) to study the reclamation of bat-inhabited mine works, put the new knowledge to practical use, and monitor the results. Rochester added its own financial support to a National Fish and Wildlife Foundation grant for the Gannon-Sherwin study.
Simply moving big-eared bats from one shaft to another was not enough to ensure survival. Because their habitat needs vary according to seasonal, reproductive, hibernation, and feeding requirements, careful planning was required for successful relocation. The broad extent of workings at Nevada Packard made it an ideal setting to conduct the research and develop a model.
The project included winter and summer surveys and an analysis of 79 candidates for alternative roosting sites, of which six were selected as optimal. Two exclusions were undertaken, each planned to minimize risks to the bats. Subsequent surveys found no bats in the old workings, and additional surveys are planned to confirm that. Meanwhile, bat-friendly gates are planned at the six alternative sites, where monitoring continues.
The systematically collected data, both fundamental research and its application in the field, already have been the subject of four peer-reviewed publications, with at least seven more in various stages of completion. Much of the exclusion and habitat information has already been reported to the Nevada Division of Wildlife and the U.S. Bureau of Land Management to help similar efforts in the future.
“We are proud of what happened here,” the company said. “The old miners created the habitat. The new miners cleaned up after the old, found the bats new homes, and improved public safety, while helping add to the scientific knowledge base.”