1. School of Resource and Environmental Management, Simon Fraser University, Burnaby, BC, Canada V5A 1S6
2. Hakai Institute, Heriot Bay, British Columbia, Canada V0P 1H0
3. Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA 95060, USA
4. Department of Biological Science, Florida State University, Tallahassee, FL 32306, USA
5. Department of Zoology, The University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z4