ENERGY METABOLISM OF THE WHITE-FOOTED MOUSE, <i>PEROMYSCUS LEUCOPUS NOVEBORACENSIS</i>, AFTER ACCLIMATION AT VARIOUS ENVIRONMENTAL TEMPERATURES

Abstract

Acclimation of white-footed mice to successively lower temperatures (30 °C., 20 °C., 10 °C.) had no effect on average initial oxygen consumption levels during exposure to environmental temperatures from 30 °C. to −26 °C., but prolonged the time that the initial levels could be maintained. When the initial oxygen consumption could no longer to maintained, there was a gradual decline to the torpidity level. The duration of this metabolism decline period increased only slightly with increase in total duration of the test. The effect of acclimation on ability to maintain metabolism appears sufficient to account for its influence on resistance to low temperatures in this species.