Seasonal variation of thermoregulation in the Florida pocket gopher, Geomys pinetis

Abstract

1. 1. Thermoregulation of Geomys pinetis was measured at different seasons in samples of newly captured gophers and seasonal changes in the thermal environment of gophers in the field were monitored. 2. 2. Resting pocket gophers have a reduced basal rate of metabolism and increased thermal conductance during warmer months of the year. 3. 3. Actively digging gophers have rates of metabolism 3–5 times basal rate and body temperature during activity rises to approach lethal levels. 4. 4. In the laboratory gophers reduce their daily activity period at higher ambient temperatures. 5. 5. The ambient temperatures at which excessive increases of body temperature occur during activity are shown to be similar to the minimum available burrow temperatures during the summer months. The seasonal changes in thermoregulatory competence and the reduction of activity at high ambient temperatures are seen to be necessary adaptations to survival in a warm moist burrow.