1. Oregon Cooperative Fish and Wildlife Research Unit Department of Fisheries and Wildlife Oregon State University 104 Nash Hall Corvallis Oregon97331USA
2. U.S. Geological Survey Oregon Cooperative Fish and Wildlife Research Unit Department of Fisheries and Wildlife Oregon State University 104 Nash Hall Corvallis Oregon97331USA
3. H.T. Harvey & Associates Los Gatos California USA
4. Applied Ecology Group Donana Biological Station EBD‐CSIC Avd. Americo Vespucio n.26 Seville41092Spain