LIKE many people, birds sing to show off. Singing demands neurological sophistication and physical stamina and is thus a good signal of what fine mates (and bad opponents) they would make.

跟很多人一样，鸟用鸣叫来炫耀自己。鸟儿的鸣叫需要复杂的神经系统和良好体力的配合，因而能很好地显示出它们会是多么优秀的配偶(强有力的竞争对手)。