Couch’s spadefoots range from southeastern California through southern Arizona and southern New Mexico. During summer monsoons, the spadefoot emerges from its subterranean estivation to breed in the temporary ponds created by the heavy runoff. The cue for emergence is not moisture, but low frequency sound or vibration, most likely caused by rainfall or thunder. (Photo: AOLT, Vanessa Bechtol)

where we woRk
Arizonans cherish the legendary natural wonders that grace our region: world-class sunsets, amazing plant and animal diversity, and a cultural history that spans thousands of years. Arizona harbors greater plant and animal species diversity than any other non-coastal state in the country - third only to California and Texas and has the eighth highest number of endemic (unique to the area) species, with 135 species found no where else in the world (The Nature Conservancy, Earth Day 2002). As we learn more about the plants and animals that comprise the rich natural tapestry that inspires our imaginations, we realize Southern Arizona is at the center of a marvelous fusion of distinct ecological landscapes.

The majority of Southern Arizona is part of the Sonoran Desert which extends west into California and south into Mexico, and claims the greatest diversity of vegetative growth of any desert in the world. (Nabham & Okitjub 1994). The Sonoran Desert is also recognized as an exceptional birding area within the United States with forty-two percent (261 of 622) of all terrestrial bird species found here during some part of the year. (World Wildlife Fund, 2001). The Sonoran Desert harbors two endemic (unique to the area) bird species, the highest level of bird endemism in all of the United States - both in Southern Arizona along the Arizona-Mexico border. The U.S. portion of the Sonoran Desert also boasts 58 species of reptiles, including six species of rattlesnake.

In addition, Southern Arizona is part of a system of mountain ranges and valley floors called the Southwestern Sky Island Ecosystem. The "Sky Islands" of Southern Arizona are part of a unique assemblage of approximately 27 mountain ranges whose vegetation varies from desert scrub at the valley floor to forests at higher elevations. Sky Island ecosystems support many perennial streams in an arid climate, have a high number of endemic species, and harbor the most game species as well as most of the threatened and endangered species in the Southwest (Warshall, 1995).

Southern Arizona is also experiencing tremendous human population growth. The State of the Environment for 2002 published by the Sierra Club reports that development consumes one acre an hour in Maricopa County and one acre every two hours in Pima County. As we continue this pace of conversion of land from natural habitat to the built environment we threaten the natural resources we value. The Nature Conservancy's statewide study reports more than 13 percent of Arizona's species are considered at risk. Arizona ranks seventh nationwide in the number of species at risk, fifth for both plants and amphibians, with more native fish species at risk (86%) than any other state.