Adrenal Weight in Prairie Deer Mice (Peromyscus maniculatus bairdii) and White-Footed Mice (Peromyscus leucopus noveboracensis)

Abstract

Adrenal weights were obtained for 662 Peromyscus leucopus noveboracensis and 281 wild Peromyscus maniculatus bairdii . The relationship of adrenal weight to body weight was explored using a number of parameters for size of the animals. The best linear fit for adrenal weight for both species was on body weight ,73, although this was only slightly better than for body weight 67. From these relationships it appears that adrenal weight is directly related to surface area and by inference to total metabolism and oxygen consumption. However, adrenal weights of P. m. bairdii are absolutely and relatively much less than those of P. leucopus and the rate of increase in adrenal weight with increasing body weight is much greater in leucopus . It is inferred that these differences reflect basic physiological and probably behavioral differences between these two species. There was no evidence of an increase in adrenal weight in females at maturity, thus raising questions concerning corticoid binding in these animals. Similarly, there was no suggestion of a rise (or fall) in the adrenal weight at maturity in males. Finally, it was suggested that in many instances adrenal weight provides a rapid and certain means for differentiating between P. leucopus and P. m. bairdii .