Fig. 1 GPCA El Tokio study site in Mexico (encompasses the states of Nuevo Leon, San Luis Potosi, Zacatecas and Coahuila) and experimental design. (A) Grassland types and selected grassland locations (3 in each grassland type). (B) Experimental design: each grassland location had one site with active prairie dog burrows (WP) and one site without (WOP). A 30x30 m quadrant was delimited in each site with 6 plots each, further divided into two temporal subplots.