In his book Political Ecologies of Cattle Ranching in Northern Mexico, geographer Eric Perramond offers a fascinating description of the linkages among choice of cattle breed, farm and ranch practices and the resulting groundwater levels in the Río Sonora of northern Mexico, with irrigated farm fields once used to grow food for human inhabitants now providing an “ecological subsidy” for the increasingly meaty cattle raised on the surrounding ranches:
The large, meat-bearing cattle species now common in the Borderlands are a far cry from the rangy, tough criollo cattle that once roamed the deserts. Exotic, largely Euro-American crossbreeds, real hybrids, now lumber across rangelands of northern Mexico. Forage scarcity on the ranges has been “bred,” created by the adoption of these resource-hungry breeds.
This then maps to water use in the farmed valley lands:
The irrigated floodplain of the Río Sonora, once planted in staple food crops and a diverse mix of vegetables and specialty plants, now grows almost entirely alfalfa in both planting seasons.”
Wet subsidizes dry and water tables drop, Perramond writes: “These are hybrid animals, hybrid landscapes, and hybrid livelihoods in the truest sense of the word.”