METABOLISM AND THERMOREGULATION IN THE EASTERN HEDGEHOG ERINACEUS CONCOLOR

Body temperature and oxygen consumption were measured in the eastern h edgehog, Erinaceus concolor Martin 1838, during summer at ambient temp eratures (T-a) between -6.0 and 35.6 degrees C. E. concolor has a rela tively low basal metabolic rate (0.422 ml 0(2).g(-1).h(-1)), amounting to 80% of that predicted from its body mass (822.7 g). Between 26.5 a nd 1.2 degrees C, the resting metabolic rate increases with decreasing ambient temperature according to the equation: RMR= 1.980-0.057 T-a. The minimal heat transfer coefficient (0.057 ml O-2.g(-1).h(-1).degree s C-1) is higher than expected in other eutherian mammals, which may r esult from partial conversion of hair into spines. At lower ambient te mperature (from -4.6 to -6.0 degrees C) there is a drop in body temper ature (from 35.2 to 31.4 degrees C) and a decrease in oxygen consumpti on (1.530 ml O-2.g(-1).h(-1)), even though the potential thermoregulat ion capabilities of this species are significantly higher. This is evi denced by the high maximum noradrenaline-induced non-shivering thermog enesis (2.370 ml O-2.g(-1).h(-1)), amounting to 124% of the value pred icted. The active metabolic rate at ambient temperatures between 31.0 and 14.5 degrees C averages 1.064 ml O-2.g(-1).h(-1); at ambient tempe ratures between 14.5 and 2.0 degrees C AMR = 3.228 - 0.140 T-a.