The reintroduction of bison to the Chihuahuan Desert in northern Mexico is having a major positive impact on the ecosystem. Nearly 50 bison were brought to the Cuatrociénegas nature reserve in Coahuila state last year, and they’re already helping to “reactivate the dynamics and the health of the ecosystem”. The bison were extirpated from the area by human activities in the 19th century, but their return is being hailed as a historic moment. The reserve is home to several hundred plant and animal species, including many that are critically vulnerable or endangered.
The bison are having a number of beneficial effects on the ecosystem. They’re helping to prevent the outbreak and spread of fires by eating dry vegetation, and their grazing is promoting the generation of plant life in the area. Their hooves are also tilling the soil, creating openings that let in water and allowing flora to grow. Additionally, the bison are acting as inadvertent spreaders of plant seeds, which can become entangled in their fur and then be shaken loose as they move around. Their manure is also aiding the fertility of the soil by attracting dung beetles, which improve the nutrient content of the soil and aerate the subsurface.
The reintroduction of the bison is also having a positive impact on other animals in the area. Hidden cameras have captured the return of previously-absent animals such as pumas, lynxes, and the collared peccary. Local bird species are also using the bison’s fur to build nests. The director of the Fundación Pro Cuatrociénegas, Gerardo Ruiz Smith, has described the bison as “landscape architects” that are “molding and regenerating their surroundings”. The reintroduction of the bison is a significant step towards restoring the health and biodiversity of the Chihuahuan Desert ecosystem.