At water temperatures below 15 C, Ambystoma tigrinum moved in response to oxygen and thermal gradients, remaining in shallow water during the day and returning to deep water at night. Under these conditions, activity was reduced. In the absence of thermal and oxygen gradients at water temperatures below 15 C, movements were random. At water temperatures above 15 C, movement was random and activity increased. Temperature appeared to be the most important factor governing winter and spring activity and light seemed most important in governing summer activity.