Metabolic levels and biological strategies in shrews

摘要

Measurements of the energy consumption of shrews have, over the past 30 years, regularly shown far higher values than expected according to their body size. The question that Poczopko was asking in 1971, of whether there is a deviation from the typical eutherian basal metabolism, could finally be answered in the affirmative in 1976 (Vogel, 1976). Several authors are of the opinion that the special physiological condition of shrews is determined by their small size (Gebczynski, 1965, 1971a; Pucek, 1970; P. Gehr, personal communication), but this hypothesis is only partly borne out by the facts. Because among the Soricidae, independently of body size, the subfamily Crocidurinae show markedly lower metabolic rates than the subfamily So-ricinae (Vogel, 1976), other factors must be involved. I consider that the different metabolic levels may be explained as a physiological adaptation to differing climatic conditions because, according to zoogeographical and palae-ontological data (Repenning, 1967), the Crocidurinae evolved in the palae-otropical region in contrast to the Soricinae, which evolved in the holarctic region (cf. Table 1).