No Decline in Salamander (Amphibia: Caudata) Populations: 

 A Twenty-Year Study in the Southern Appalachians 



Nelson G. Hairston, Sr., and R. Haven Wiley 



Department of Biology, University of North Carolina 



Chapel Hill, North Carolina 27599-3280 



ABSTRACT — Identical observations, conducted 1-4 times per year 

 for 15-20 years at two locations in the southern Appalachians, 

 have yielded quantitative data on populations of six species of 

 salamanders. Although the numbers have fluctuated for various 

 reasons, there has been no trend in the numbers of any of the 

 species. The "world-wide decline of amphibian populations" has not 

 occurred in the two localities studied. 



Recently, much attention has been given to a decline in many 

 populations of amphibians (Barringer 1990, Blaustein and Wake 1990, 

 Phillips 1990). There is a suggestion by some authors that there is a 

 general cause for a supposed "world-wide" decline. We do not deny 

 that many amphibian species have decreased in abundance. Among 

 the causes that have been suggested are acid precipitation (Harte and 

 Hoffman 1989, Beebee et al. 1990) and ultraviolet increase due to 

 ozone depletion (Barringer 1990, Blaustein and Wake 1990, Phillips 

 1990). The same authors have considered overcollecting and rejected 

 it as a general cause. Habitat destruction is also widely mentioned. 

 The last cause is common to all species, except for some pioneering 

 ones, and would not apply only to amphibians. The situation is regard- 

 ed by many herpetologists as very serious, so much so that the World 

 Conservation Union (IUCN), Species Survival Commission, has activated 

 a Declining Amphibian Populations Task Force. This group has estab- 

 lished local subgroups throughout the United States and elsewhere in 

 the Americas to promote research on the problem. 



If there has been a general cause for the decline in amphibian 

 populations, all amphibian populations should be involved; if they are 

 not, the original claim of a "world-wide decline" must be modified, 

 either by eliminating some taxonomic groups, some ecologically distinc- 

 tive species (e.g., those lacking aquatic stages), or some geographic 

 regions. Study of apparently exceptional cases might give clues to the 

 causes of declines that have been observed. 



METHODS 



In September 1971 and 1972 N.G.H. and classes from the 

 University of Michigan studied the distribution of the colors of 



Brimleyana 18:59-64, June 1993 59 



