Our l.iviiif; Rcsdiurcx — Replilcs ami Amphibians 



125 



• Aiiiphihians predominate in small lorest streams 

 of the Pacific Northwest. Because timber is har- 

 vested without adequate streamside protection, 

 many populations ol the tailed I'rog {A.siciphiis 

 tniei) and torrent salamanders {RhyacoUilon 

 spp.) have been severely affected; some popula- 

 tions soon will warrant consideration for listing. 



• The western toad (Bufo boreas) once was com- 

 mon in the Rocky Mountains, but now occurs at 

 fewer than 20% of known localities from south- 

 em Wyoming to northern New Mexico. 



• Many salamander and frog populations in the 

 southeastern United States have been negatively 

 affected, some severely, because of degradation 

 of stream habitats (e.g.. the hellbender, 

 Cnptohnimiiiis allegcmiensis) and conversion of 

 natural pinewood and hardwood forests and asso- 

 ciated wetlands (e.g., gopher frog, Raiia capita) 

 to plantation forestry, agriculture, and urban uses. 



• Leopard frogs {Rana spp.). which are used in 

 teaching and research institutions, were once 

 abundant in most of the United States. 

 Populations in this diverse group have declined, 

 sometimes significantly, in midwestem. Rocky 

 Mountain, and southwestern states. 



Causes of Declines 



No single factor has been identifieid as the 

 cause of amphibian declines, and many unex- 

 plained declines likely result from multiple 

 causes. Human-caused factors tnay intensify 

 natural factors (Blaustein et al. 1994b) and pro- 

 duce declines from which local populations 

 cannot recover and thus ihey go extinct. Known 

 or suspected factors in those declines include 



Western load {Bufo boreas). 



destruction and loss of wetlands (Bury et al. 

 1980); habitat alteration, such as impacts from 

 timber harvest and forest management (Com 

 and Bury 1989; Dodd 1991; Petranka et al. 

 1993): introduction of non-native predators, 

 such as sportfish and bullfrogs, especially in 

 western states (Hayes and Jennings 1986; 

 Bradford 1989); increased variety and use of 

 pesticides and herbicides (Hine et al. 1981); 

 effects of acid precipitation, especially in east- 

 ern North Ainerica and Europe (Freda 1986; 

 Beebee et al. 1990; Dunson et al. 1992); 

 increased ultraviolet radiation reaching the 

 ground (Blaustein et al. 1994a): and diseases 

 resulting from decreased immune system func- 

 tion (Bradford 1991; Carey 1993; Pounds and 

 Crump 1994). 



A Success Story: 



The Barton Springs 

 Salamander 



A success story from the Edwards Plateau 

 in Texas illustrates the importance of 

 baseline ecological data, current science, 

 and the types of partnerships essential for 

 conservation of amphibians. The recently 

 described Barton Springs salamander 

 (Eurycea sosonim) occurs only in three 

 springs within about 300 m (984 ft) of each 

 other within the city limits of Austin. This 

 salamander has one of the smallest known 

 distributions of any North American verte- 

 brate. 



Pools associated with the two primary 

 springs had been developed as municipal 

 swimming and wading pools, and standard 



cleaning procedures had eliminated most 

 salamanders. With cooperation of city 

 authorities and local volunteers, pool main- 

 tenance practices detrimental to the sala- 



mander were modified, and populations of 

 the salamander seem to be increasing and 

 expanding their ranges within the spring sys- 

 tem. 



Barton Springs salamander {Eurycea sosonim). 



