common. Towns can contain hundreds of animals, but generally have fewer than 50, with a single alpha male. Sometimes, spotted ground squirrels or burrowing owls share the burrow with its rightful owners. Population structure In 1956, the Mexican prairie dog was reported as occurring in Coahuila, Nuevo León, and San Luis Potosí. By the 1980s, it had disappeared from Nuevo León. As of 1992 its complete range was roughly 600 km2 (372 mi2). Viewed as a pest and an obstacle to agriculture and cattle raising due to their burrowing and frequent consumption of crops, it was frequently poisoned, and became endangered in 1994. Mexican prairie dogs currently inhabit less than 4% of their former territory and have suffered a 33% decrease in range between 1996 and 1999. The current habitat of Mexican prairie dogs is in the region known as El Tokio. These are the grasslands located in the convergence of the states of San Luis Potosí, Nuevo León, and Coahuila. Due to the underground structures in which many prairie dogs live, it is difficult to accurately survey populations. The use of satellite imagery has proven to be helpful in documenting areas in which prairie dogs reside. Conservation groups such as Pronatura Noreste and Profauna, with the help of donors, carry out conservation efforts for the protection of prairie dogs and associated species, such as shorebirds and birds of prey. Pronatura Noreste, as of February 2007, has signed conservation easements with ejidos and private owners for the protection of more than 42,000 acres (170 km2) of Mexican prairie dog grasslands. References External links ARKive - images and movies of the Mexican prairie dog (Cynomys mexicanus) Animal Info: Mexican prairie dog DesertUSA: Prairie dogs Prairie dogs videos (in English) Pronatura Noreste in the Chihuahuan Desert Prairie dogs Endemic mammals of Mexico Fauna of Northeastern Mexico Mexican Plateau Natural history of Coahuila Natural history of San Luis Potosí Mammals described in 1892