Voyageurs National Park (VNP), in northern Minnesota, supports one of the highest densities of beavers (Castor canadensis) in North America. Beavers have a profound impact on VNP terrestrial and aquatic ecosystems. Their population dynamics and behaviors affect nutrient and methylmercury cycling, nongame fish production, wildfire behavior, forest succession, invasive plant dynamics, habitat creation for other wildlife, and predator-prey dynamics. In recognition of the cultural, ecological, and scientific importance of beavers to Voyageurs National Park, the park initiated a new beaver research and monitoring program in 2004, in collaboration with several universities and other natural resource management agencies.
Among other things, this project investigates the prevalence of diseases and parasites in the beaver population. Tularemia was positively detected in five dead beavers collected in the park in 2007. Much still remains to be learned about the role of beavers in the epidemiology of important emerging diseases.
In 2007, Minnesota Zoo’s Ulysses S. Seal Conservation Grant Program provided funding to associate veterinarian Dr. Tiffany Wolf to participate in the VNP beaver research and monitoring program. She collected biological samples from captured beavers to screen for pathogens and to establish baseline health data for the VNP beaver population. Dr. Wolf also surgically implanted intra-abdominal radio transmitters in 30 free-ranging beavers to help monitor beaver movements during the winter. This project is ongoing and Dr. Wolf will continue to participate in it.