Metabolism and thermoregulation in the eastern hedgehogErinaceus concolor

Abstract

Body temperature and oxygen consumption were measured in the eastern hedgehog,Erinaceus concolor Martin 1838, during summer at ambient temperatures (Ta) between-6.0 and 35.6°C.E. concolor has a relatively low basal metabolic rate (0.422 ml O2·g-1·h-1), amounting to 80% of that predicted from its body mass (822.7 g). Between 26.5 and 1.2°C, the resting metabolic rate increases with decreasing ambient temperature according to the equation: RMR=1.980-0.057Ta. The minimal heat transfer coefficient (0.057 ml O2·g-1·h-1·°C-1) is higher than expected in other eutherian mammals, which may result from partial conversion of hair into spines. At lower ambient temperature (from-4.6 to-6.0° C) there is a drop in body temperature (from 35.2 to 31.4° C) and a decrease in oxygen consumption (1.530 ml O2·g-1·h-1) even though the potential thermoregulation capabilities of this species are significantly higher. This is evidenced by the high maximum noradrenaline-induced non-shivering thermogenesis (2.370 ml O2·g-1·h-1), amounting to 124% of the value predicted. The active metabolic rate at ambient temperatures between 31.0 and 14.5° C averages 1.064 ml O2·g-1·h-1; at ambient temperatures between 14.5 and 2.0° C AMR=3.228-0.140Ta.