Corridors for Migration
Donaldson, Mac, Endangered Species Bulletin
The beautiful Cienega Valley in southern Arizona is a perfect example of a viable international wildlife corridor. Located within 20 miles (32 kilometers) of the U.S./Mexico border, it boasts a 9-mile (15-km) long perennial stream and is home to a rich variety of plants and animals, including five endangered species, three threatened species, and innumerable migratory birds. The heart of this corridor is the newly created Las Cienegas National Conservation Area. This intermountain grassland has important ties to habitats in northern Sonora and Chihuahua in Mexico through a similarity of soils, elevation, and annual rainfall.
In the 1980s, under the visionary leadership of the then Bureau of Land Management director for Arizona, Dean Bibles, a series of land exchanges took place to protect the landscape between the Coronado National Forest along the Mexico border and the Catalina/Rincon mountain forest complex from commercial development. The result was a migratory corridor of mountains and valleys with hydrological reserves in place to facilitate the movement of a great variety of species. Today, this public land is used for wildlife conservation and compatible ranching and recreational activities.
Human migration is one of many factors at work in the Cienega Valley. International smuggling of contraband and undocumented workers does have impacts upon the landscape. In this part of Arizona, few of these impacts are expected to be detrimental to wildlife and their habitat over the long term. Human migration has occurred in this region for a long time, just as wildlife crosses the same international borders.
Probably the most publicized large mammal that uses these migratory paths is the jaguar (Panthera onca), which models well the necessity for wildlife corridors. …