Development of thermoregulation in Richardson's ground squirrel, Spermophilus richardsonii

Publisher Website
Google Scholar
Abstract
Development of thermoregulation in S. richardsonii was investigated by determining the ability of neonates to maintain a normal body temperature when exposed to 30.degree. and 25.degree. C, to maintain an elevated O2 consumption (cm3 O2/g per hour) at 21.degree. C compared with that at 35.degree. C, and to move toward a warm object and assume curling postures when exposed to the cold. Newborn animals were essentially poikilothermic but by day 5 showed strong thermotaxis. By 30 days, the age of emergence from natal burrows, homeothermy had developed to the point at which normal body temperature could be maintained for at least 2 h at an ambient temperature of 25.degree. C. This process was correlated with improvements in heat production and heat retention. Subsequent growth was marked by a decreased metabolic response to cold (21.degree. C) owing to decreasing thermal conductance.