Cochise PARCAs: Conserving the Southwest’s Biological Richness

Although southern Arizona is often associated with harsh heat and dry deserts, the area’s biodiversity stands as a testament to a beautifully rich landscape. With flashes of bright orange and yellow, western tanagers fly among mountaintop trees. Cottonwood and desert willow trees grow along lush wetlands. Apache trout swim in cold, high-elevation streams. Montezuma quail roam the pine-oak woodlands. Desert cottontails and Sonoran Desert tortoises traverse the sands and brush of the desert vistas dotted with iconic saguaro cacti. Jaguars even inhabit Cochise County.

In terms of herpetofauna or “herps” (reptiles and amphibians), this area–encompassing the Chihuahuan Desert to the east and the Sonoran Desert to the west and all the habitat in between–is unparalleled. In most US states, we’re focused on protecting between twenty and forty herp species. In Arizona, our two Cochise PARCAs (Priority Amphibian and Reptile Conservation Areas), Cochise East and West, each boast more than forty herp species.

This amazing species richness results from the region’s vast array of habitat types. Arid (dry) conditions dominate much of the area, and the resilient animals here have evolved to live life without much water. Take the Couch’s spadefoot, for example. This frog conducts its life almost entirely underground, away from the heat, emerging only during rare desert rains to breed. Gila monsters, the largest and only venomous lizards in the US, also retreat underground and binge drink during rains. 

But not everything is dry. Streams run through rocky canyons; here, canyon treefrogs use their adhesive toe pads to traverse boulders. Toads like the red-spotted and Great Plains breed in pools that form during summer rains. And the Chiricahua Mountains, Huachuca Mountains, Santa Rita Mountains, and other ranges abruptly rise from the desert, forming “sky islands.” Here, cool Madrean pine-oak forests harbor species like the Mexican fox squirrel and the whiskered screech owl, as well as reptiles like the Arizona ridge-nosed rattlesnake (Arizona’s state reptile) and amphibians like the federally listed Threatened Chiricahua leopard frog. 

While the biodiversity of the Cochise PARCAs is awe-inspiring, it’s also highly threatened. The PARCAs’ location by the Mexican border means that these diverse habitats are impacted by infrastructure, vehicles, and artificial lighting. Other threats abound, too. There’s mining runoff, disease, the ever-looming expansion of urban areas, and habitat destruction and fragmentation due to agriculture and other development. 

Climate change is another concern, as shifts in temperature and precipitation patterns alter the suitability of habitats. Many species here are highly specialized, and long-term drought, changes in groundwater availability, and increased temperatures are throwing off the delicate rhythms and patterns of life that evolved over millennia.

Invasive species pose a particularly urgent threat. Bullfrogs and crayfish disrupt wetland food chains. Flammable invasive grasses that didn’t evolve to withstand fire are contributing to large-scale, destructive events that are burning hotter than historic fires and spreading to areas that didn’t typically burn in the past.

ARC’s work in the Cochise PARCAs is focused on habitat protection, restoration of degraded habitats, inventorying and monitoring populations of imperiled herps to determine which targeted conservation actions would be most effective, and community outreach and collaboration. Maintaining the many varied habitats of the region will mean that all of the species that rely on them can thrive, from birds to mammals to herpetofauna. Our main goal here, as in many parts of the Desert Southwest, is to help restore the hydrology and the surrounding habitats. 

To do so, we’re removing invasive plants that alter water availability and quality, such as nonnative cattails, and planting native plants that have been impacted by competition with invasives and increased wildfire. The plant communities surrounding the region’s wetlands are vitally important for water quality, preventing erosion and acting as filters. And healthy wetlands are crucial for vulnerable herp species like the Chiricahua leopard frog. 

Unfortunately, the area’s wetlands also house invasive predators such as bullfrogs and crayfish, both of which wreak havoc on the ecosystem by eating large numbers of native amphibians and fishes and their eggs. Plus, crayfish mow down pond vegetation on a large scale, destroying the microhabitats amphibians and fish need and affecting water availability and quality. We’re controlling these two species in several ways. For example, we remove bullfrog egg masses. We also catch invasive crayfish, extract the gonads of the males, and release them back into the wetlands, where they mate with females but can’t produce offspring. 

Through these actions and more, we’re giving populations of at-risk species their best chance of being resilient to the changing world they will continue to face. It’s all worthwhile when we see the breathtaking species and landscapes of the Cochise PARCAs, which epitomize the incredible diversity that can flourish in even the harshest of environments. This rich web of life spans sprawling deserts, Rocky Mountains, plunging canyons, and lush riparian corridors, and nothing showcases the region’s diversity like the native reptiles and amphibians. With your help, we are working to secure a future for them and all of Cochise County’s biodiversity.