1. New York Cooperative Fish and Wildlife Research Unit, Department of Natural Resources and the Environment Cornell University Ithaca New York USA
2. Department of Natural Resources and the Environment Cornell University Ithaca New York USA
3. Institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu People's Republic of China
4. U.S. Geological Survey, New York Cooperative Fish and Wildlife Research Unit, Department of Natural Resources and the Environment Cornell University Ithaca New York USA