The animals gone 200 years came back as landscape architects

Three bison stepped into El Santuario, a 4,000-hectare section of Mexico's Cuatrociénegas reserve in Coahuila, in August 2025. By November, 44 more had joined them. The animals had been absent from this part of the Chihuahuan Desert for 200 years, hunted out in the 19th century, and by the time anyone asked what was missing, the degraded version had become the baseline. Within months, things started moving. When bison run, their hooves break the soil surface, pulling in water and loosening ground compacted for decades. Seeds catch in their fur and fall loose as they travel. Their grazing thins the dry vegetation that feeds wildfires. Hidden cameras have since caught pumas, lynxes and collared peccary passing through, and local birds pulling bison fur for their nests. Gerardo Ruiz Smith, director of Fundación Pro Cuatrociénegas, calls bison "landscape architects," and he means it more literally than it sounds.