1. Alberta Conservation Association Lethbridge AB T1J 0P6 Canada
2. Wildlife Biology Program, Department of Ecosystem and Conservation Sciences, W.A. Franke College of Forestry and ConservationUniversity of Montana Missoula MT 59812 USA
3. Wildlife Biology Program, Department of Ecosystem and Conservation Sciences, W.A. Franke College of Forestry and ConservationUniversity of MontanaMissoula MT 59812 USA