Thesis Title

The Effect of Temperature and Digestion on Metabolism in Black Rat Snakes, Elaphe Obsoleta Obsoleta

Date of Graduation

Spring 2004


Master of Science in Biology



Committee Chair

Brian Greene


metabolism, temperature, digestion, rat snake, Elaphe o. obsoleta

Subject Categories



Temperature is critical to the understanding of snake energetics due to the strong thermal dependencies of metabolism. To identify sources of metabolic variation in Elaphe obsoleta obsoleta, I investigated the effects of mass, body temperature, and digestion on oxygen consumption at 20, 25, and 30°C. Mass-specific standard metabolic rates (SMR) for rat snakes increased as a function of temperature. SMR did not change due to time of day effects. Slopes for 20 and 30°C treatments did not significantly differ. There was not a significant difference in O₂ consumption from 20 to 25°C. There was a significant difference in preferred temperature range of rat snakes. Digestive efficiency ranged from 25.6-75.7%. The mean metabolic rate during digestion was approximately four times as high as the mean SMR for relative meal sizes of 8-16% at 25°C. The amount of energy from the meal needed for oxygen consumption was 42.2 ± 1.42%. SMR of E. o. obsoleta resemble values for general snake equations. Preferred temperature range (23.3-33.1°C) is similar compared to northern populations, and thermal sensitivity (Q₁₀) is within the normal range for snakes (2-3).


© April M. Brennan