1. Birds and mammals are homoeothermic animals, able to maintain a constant body temperature regardless of the external environment.
鸟类和哺乳类是具有恒温机能的动物，能够在外界环境改变的情况下保持恒定的体温。

2. Homoeothermic animals have evolved various physiological mechanisms to regulate their body temperature and adapt to different climates.
具有恒温机能的动物进化出各种生理机制，以调节体温并适应不同的气候条件。