Date of Award


Document Type


Degree Name

Master of Science (MS)




The purpose of this study was to obtain accurate quantitative estimates of the high temperature tolerance of five species of anuran amphibians, Bufo hemiophrvs. Rana plpiens, R. sylvatlca, R. septentrionalis, and Pseudacris nigrita. B. hemiophrvs and P. nlqrlta were collected in the vicinity of Grand Forks, North Dakota; the remaining species were collected at Itasca State Park, Minnesota. Tolerance was measured using the water submersion method described by Schmid (Ecology, 1965). The data were analysed by several statistical methods and the results were compared. The order of tolerance (highest to lowest) was B.. hemiophrvs, R. plpiens, R septentrionalis, P . nlqrlta, and R. sylvatlca. The interspecific tolerance variation of these anurans was correlated with their known ecologies and geographic distributions. There were no intraspecies correlations among variations of tolerance, sex or weight.