晚成性哺乳动物体温调节能力的胎后发育

按照体温调节能力的发育情况，哺乳动物的生长发育可分为早成性、晚成性和未成熟性3类。本文主要综述了晚成性哺乳动物体温调节能力的发育特点。这类动物的幼体出生时一般身体裸露，热传导率较高，产热能力较差，不能进行有效的体温调节。当环境温度低于热中性区时，单独的个体不能维持较高的恒定体温。但晚成性幼体也具有一定的体温调节能力，当受低温刺激时，即使新生幼体也会具有增加代谢率的反应；同时结合亲体关怀和幼体之间的聚群效应以及巢的保温作用等方式，仍能使其体温维持在一个较高的水平。晚成性幼体生理性产热的不足，也可看作是一种有利的特点，这样可以减少能量在体温调节方面的消耗，从而增加用于生长发育的能量。文章最后对可能的发展方向进行了展望。

Postnatal Development of Thermoregulation in Altricial Mammals

Mammalian neonates can be divided into three categories, namely precocial, altricial, and immature, mainly according to their establishment of successful thermoregulation. The altricial mammals are often born naked with poor insulation and weak thermogenic abilities. So they cannot thermoregulate efficiently in their early lives. When ambient temperature falls below the thermal neutral zone, isolated young cannot maintain high constant body temperatures. However, the newborns can increase thermogenesis when cold exposed, which is different from poikilotherms. The altricial mammals often show careful parental care and the young can huddle together to prevent heat loss. Thus, even newborns can maintain their body temperatures at a relatively high level in the nest. The deficiency of physiological heat production in the early stages of altricial mammals can be regarded as advantageous for development because it can promote growth and development by decreasing the energy allocation to thermoregulation. Finally the possible research trends of this field are proposed.