1. U.S. Geological Survey, Southwest Biological Science Center, Grand Canyon Monitoring and Research Center, 2255 N. Gemini Dr., Flagstaff, AZ 86001, USA
2. School of Earth and Sustainability, Northern Arizona University, 524 Knoles Drive, Flagstaff, AZ 86011, USA
3. Conservation Science Partners, Inc., 11050 Pioneer Trail, Suite 202, Truckee, CA 96161, USA