An evaluation of methods for monitoring Ensatina eschscholtzii oregonensis in the Reed College Canyon

Author: Kyla Zaret
Advisor: Robert Kaplan
Year: 2002

Abstract: Amphibians are likely indicators of environmental degradation, as evidenced by cases of disappearing and declining amphibian populations worldwide. However, distinguishing between natural fluctuations in amphibian population size and trends due to human impacts is problematic. Consequently, developing standardized methods for efficiently and reliably monitoring amphibian populations over the long-term would greatly enhance conservation efforts.

Th

It was determined that the ACO and quadrat techniques detected trends in salamander count with similar power. However, sampling ACOs was much less time-consuming than sampling quadrats. Thus, the power of a monitoring program that utilizes ACOs can be adjusted by increasing the number of ACOs sampled without a subsequent increase in the amount of time needed to complete surveying. In addition, salamander encounter under ACOs was less affected by climatic variables than within quadrats. New ACOs did not effectively sample salamanders. The results of this study indicate that ACOs should be used to create an efficient and powerful program to monitor the population of E. e. oregonensis in the Reed Canyon over the long-term.