Key C, Ross C
Department of Anthropology, University College London, UK.
Proc Biol Sci. 1999 Dec 22;266(1437):2479-85. doi: 10.1098/rspb.1999.0949.
Female mammals bear the energetic costs of gestation and lactation. Therefore, it is often assumed that the overall energetic costs are greater for females than they are for males. However, the energetic costs to males of intrasex competition may also be considerable, particularly if males maintain a much larger body size than females. Using data from 19 non-human primates, this paper examines the relationship between male and female energetic costs both in the short term (daily energy expenditure) and the long term (the energetic cost of producing a single offspring). It is shown that the major determinant of sex differences in energetic costs is body size dimorphism. In the long term, the energetic costs are often greater for females, but, when male body size exceeds female body size by 60% or more, male energetic costs are greater than those for females. That is, in highly sexually dimorphic species the energetic costs of gestation and lactation for the females are matched by the energetic costs to the males of maintaining a large body size.
雌性哺乳动物承担着妊娠和哺乳的能量消耗。因此，人们通常认为雌性的总体能量消耗比雄性更大。然而，雄性间竞争对雄性造成的能量消耗也可能相当可观，特别是当雄性的体型比雌性大得多时。本文利用来自19种非人类灵长类动物的数据，研究了雄性和雌性在短期（每日能量消耗）和长期（生育单个后代的能量消耗）的能量消耗之间的关系。结果表明，能量消耗性别差异的主要决定因素是体型二态性。从长期来看，雌性的能量消耗通常更大，但是，当雄性体型比雌性体型超出60%或更多时，雄性的能量消耗就会大于雌性。也就是说，在高度两性异形的物种中，雌性妊娠和哺乳的能量消耗与雄性维持大体型的能量消耗相当。
