【英语时差8,16】鸟类荷尔蒙映射其生活策略

（单词翻译）

 In the race of life, some animals are hares, running at top speed, producing lots of young and dying quickly. Others are tortoises, maturing slowly, producing few offspring, and living a long time. There must be physiological¹ mechanisms² that regulate these differing life strategies, and researchers studying bird hormones³ have found a clue. Corticosteroids, found in many animals, are stress hormones released in the blood. If an animal is threatened by a predator⁴ or rival, the hormones allow the individual to survive by fighting or fleeing. The strange thing about corticosteroids is that, just like life strategies, they vary dramatically from one species to the next. The question is: Why?