The U.S. Fish and Wildlife Service wants to designate a network of streams running off the Mogollon Rim in Gila County as critical habitat for the endangered Chiricahua leopard frog.
The designation of some 11,000 acres in Arizona and New Mexico may save a once widespread frog from extinction, but will also create a new set of complications for any federal actions that might affect those creeks.
A series of lawsuits filed by the Centers for Biological Diversity forced the Fish and Wildlife Service to list the frog as endangered a decade ago. It took additional lawsuits and a court order to prod the federal agency to actually designate critical habitat. Environmentalists consider that designation crucial to saving any species, since it forces the federal government to take the fate of the frog into account any time it approves an action on federal land — like a grazing lease, timber harvest contract or road building project.
The listing of critical habitat for the Chiricahua leopard frog in the federal registrar included 41 areas essential to the survival of the amphibian in Arizona and New Mexico, but just two areas in Gila County.
The frog has disappeared from 320 of the 400 areas in which it has been documented, surviving in about 15 percent of its former range. However, in recent years the Arizona Game and Fish Department and the Fish and Wildlife Service have introduced about 10,000 captive reared frogs back into the wild, including in several Gila County sites.
One Gila County area proposed for critical habitat status lies just northeast of Tonto Village and includes portions of Ellison and Lewis creeks. That includes about 83 acres where the frogs have survived, although recent surveys have failed to find any frogs in Ellison Creek since 2006. However, the Fish and Wildlife Service and the Arizona Game and Fish Department have struck up agreements with ranchers to maintain small populations of frogs in springs and stock tanks, which biologists hope will eventually repopulate Ellison and Lewis creeks.
The second Gila County area includes a network of creeks and springs near Young, including portions of Crouch, Gentry and Cherry creeks. In addition, the listing would include Parallel Canyon and a number of stock tanks established by ranchers in which the frogs have set up housekeeping. The listing also includes several springs in Gila County including Pine, Rock and Carroll springs.
All told, this “Unit 24” includes more than 400 acres, including just six acres of privately owned land. Biologists found frogs in Crouch Creek, Carroll Spring, Bottle Spring, Gentry Creek and several stock tanks in the area — all of which connect to the rest of the stream stretches considered critical to the frog’s recovery. Biologists have been releasing frogs into the area to help the surviving wild populations survive and spread.
The critical habitat didn’t include streams once hopping with frogs from which the amphibians have disappeared — including Tonto Creek, the East Verde River and Fossil Creek. However, many biologists believe some of the frogs may have returned to Fossil Creek, which has turned into one of the most important refuges for native fish in the Southwest since the return of the flow of the spring to the creek five years ago.
The listing includes other areas close to Rim Country, including portions of Oak Creek and Beaver Creek near Sedona and a network of streams in the White Mountains.
Most of the 41 designated areas with critical habitat lie in southeastern Arizona.
Many of the scattered surviving populations have become increasingly isolated. Geneticists said the leopard frogs that live in streams and springs flowing off the Mogollon Rim have accumulated a roughly 2.4 percent genetic difference from the more numerous populations in the southeastern portions of the state, but will still readily interbreed with their southern cousins.
The small, adaptable, olive-green to golden Chiricahua leopard frog has distinctive, cream-colored raised spots, folds of skin on its back and sides, a stocky body, rough skin, and goggle-eyes perched high atop its head. The two- to five-inch long frogs also have a distinctive call — kind of a long, weird snore that goes on for about two seconds.
The frogs face a bewilderment of threats — mostly caused by humans. Biologists say that dams, wells and water diversion have degraded or destroyed more than 90 percent of the riparian habitat in the state. Moreover, introduced species like bullfrogs, crayfish, bass, catfish, tiger salamanders, trout and other stream dwellers have taken a heavy toll on the frogs, their polliwogs and their eggs.
The female frogs lay jelly-like masses of 300 to 1,300 eggs throughout the year, depending on water temperatures. However, few of the eggs and wriggling tadpoles survive the ruthless gauntlet of predators.
The frogs have also suffered from a variety of diseases and fungal infections, some of which reflect the degraded condition of the streams on which they rely.
The frogs serve as a sort of “canary in the coal mine” when it comes to water quality —since their permeable skin readily absorbs pollutants from mine tailings and other human activities.