Our Z./\'mi,' Riwimnrs — Rejnilo, and Amphihiuns 



I3J 



disappeared from about 99% of its range, and is 

 only known from one location in the state. It 

 appears to be on the verge of extinction in 

 California. 



Yavapai Leopard Frog (R. yavapaiensis) 



This frog was originally found along the 

 Colorado River and in the Coachella Valley of 

 southeastern California (Fig. 2). It has not been 

 seen in the state since the niid-l960"s and now 

 seems to be extinct at all sites examined. This 

 leopard frog has been replaced in California by 

 the introduced bullfrog (R. catesbeicma) and the 

 Rio Grande leopard frog {R. berlaudieri), which 

 are able to thrive in human-modified reservoirs 

 and canals in the Yavapai leopard frog's original 

 range (Jennings and Hayes 1994). 



Mountain Yellow-legged Frog {R. inuscosa) 



This species was historically abundant in the 

 Sierra Nevada at elevations largely above 1.829 

 m (6.000 ft), and also in the San Gabriel, San 

 Bernardino, and San Jacinto mountains of 

 southern California above 369 m ( 1,210 ft; Fig. 

 3). The mountain yellow-legged frog has disap- 

 peared from about 509c of its historical range in 

 the Sierra Nevada and about 99% of its histori- 

 cal range in southern California. Some 

 researchers believe that the widespread intro- 

 duction of non-native trout into high-elevation 

 lakes is the major reason for the decline of this 

 species in the Sierra Nevada (Bradford 1989: 

 Bradford et al. 1993). The species, however, 

 experienced massive die-offs in many parts of 

 its range during the 1970"s (Bradford 1991) 

 after several years of severe floods and drought, 

 and continues to decline in relatively pristine 

 areas such as wilderness areas and national 

 parks. 



Such observations indicate that present land- 

 management practices of setting aside large 

 tracts of land for the "protection of biodiversi- 

 ty" may not be adequate for ensuring the con- 

 tinued survival of this species. Already, the loss 

 of this frog over large areas has negatively 

 affected organisms such as the western terrestri- 

 al garter snake {Thamnopliis elegans). which 

 relied upon it as a major food source (Jennings 

 et al. 1992). To keep these populations from 

 extinction, resource managers may need to ini- 

 tiate active management efforts for mountain 

 yellow-legged frogs (such as fish eradication 

 programs in selected high-elevation lakes, fenc- 

 ing of riparian zones to exclude livestock graz- 

 ing, and relocating hiking trails and camp- 

 grounds away from sensitive riparian habitats). 



Northern Leopard Frog (R. pipiens) 



This frog was historically recorded from 

 scattered localities below 1,981 m (6.500 ft) in 





Northern red-lesaed trog (Rana aurora aiavra). 



Fig. 2. Historical and current distribution of ttie foottiill yellow-legged frog, spotted frog, and 

 Yavapai leopard frog in California based on 3,.^ 16 museum records and 171 records from other 

 sources. Dots indicate locality records based on verified museum specimens. Squares indicate 

 locality records based on verified sightings (e.g.. field notes, photographs, published papers). Red 

 dots and green squares denote localities where native frogs are e.\tant. Gold dots and blue squares 

 indicate where native frogs are presumed e.xtinct. Figure modified from Jennings and Hayes 

 (1993). 



