Lithobates yavapaiensis

Referred to in some literature as "lowland type" of leopard frog (Platz and Frost 1984). Low rate of hybridization with R. chiricahuensis. Jaeger et al. (2001) examined variation in mtDNA and morphology and concluded that certain leopard frog populations in the Virgin River/Black Canyon (Colorado River) region represent a species (R. onca) distinct from R. yavapaiensis.

Large number of occurrences still exist in central Arizona (the largest portion of United States range) but, apparently extirpated from other portions of range in the southwestern United States; information is not available for Mexico; populations declining everywhere except central Arizona; ongoing threats from habitat alteration and fragmentation and introduced species; occurs on several state or federal areas in Arizona that are being managed for the species. If the status in Mexico is determined to be drastically declining or extirpated the GRANK should be revised accordingly.

Western and central Arizona and southwestern New Mexico south to northern Sonora and northwestern Chihuahua; southcentral and southeastern California and adjacent Arizona, from San Felipe Creek to the Colorado River (Painter 1985, Jennings and Hayes 1994, Jaeger et al. 2001). Usually below 1000 meters, to 1700 meters in central Arizona (Platz and Frost 1984, Stebbins 1985). Apparently extirpated in Imperial Valley, California, and along the lower Colorado River, Arizona-California, though may be extant in some areas close to the Colorado River in Arizona (Clarkson and Rorabaugh 1989, Jennings and Hayes 1994); replaced by introduced R. berlandieri along the Colorado and Gila rivers, Arizona (Clarkson and Rorabaugh 1989). In Arizona, found in every county except Apache and Navajo with 57% of all localities occurring in Gila, Maricopa, and Yavapai counties (Sredl et al. 1997). Believed extirpated from New Mexico (New Mexico Department of Game and Fish 1997). Leopard frogs from the Virgin River drainage and adjacent portions of the Colorado River (Black Canyon), mapped as Rana yavapaiensis by Platz (1988), are now believed to represent Rana onca (Jaeger et al. 2001).

Possibly extirpated from peripheral areas of the range in New Mexico and California, but large numbers still occur in areas of Arizona. Information is not available for Mexico. In California, historical records are from 28 locations with the most recent observation in 1965. Has not been observed during recent general herpetological surveys in California and is believed to be extirpated (Jennings and Hayes 1994). In New Mexico, known from 14 historical locations. A 1995 survey of 72 potential locations in New Mexico, including six historical sites that had not been surveyed in the past 10 years, resulted in no observations. New Mexico populations are now believed to be extirpated or occurring in very low numbers (Jennings 1995, New Mexico Department of Game and Fish 1997). In Arizona, the Natural Heritage Program recorded 302 occurrences with 90% believed to be extant (Sabra Schwartz, pers. comm., 1998). An extensive 1991-1996 survey in Arizona resulted in the relocation of this species at 43 of the 115 historical localities surveyed and at 61 additional new sites (Sredl et al. 1997).

The greatest threat is habitat alteration and fragmentation and the introduction of non-native predatory and competitive fishes, crayfishes, and frogs (see Jennings and Hayes 1994, Sredl et al. 1997). Habitat alteration is the result of agricultural practices, livestock grazing, development, and reservoir construction (see Jennings and Hayes 1994). Damming, draining, and diverting of water have fragmented formerly contiguous aquatic habitats. In many areas, fragmentation has been accentuated by introduced predatory fishes, crayfish, and bullfrogs. The species has been replaced by introduced R. berlandieri along the Colorado and Gila rivers, Arizona (Clarkson and Rorabaugh 1989). These factors result in the blockage of potential dispersal corridors for recolonization. Populations are also vulnerable to large-scale mortality on a frequent basis due to drought, disease, and sulphur toxicity (Sredl et al. 1997).