[1] No Arizona Univ, Dept Biol Sci, POB 5640, Flagstaff, AZ 86011 USA
[2] No Arizona Univ, Merriam Powell Ctr Environm Res, POB 5640, Flagstaff, AZ 86011 USA
[3] Univ Lethbridge, Biol Sci, Lethbridge, AB T1K 3M4, Canada
[4] Agr & Agri Food Canada, Lethbridge Res & Dev Ctr, Lethbridge, AB T1J 4B1, Canada