Oh, you're being a really good sport about this, Marilyn,
噢,在这件事情上,你倒变成一个看得很开的人, Marilyn?nbsp;
This is because they had no natural enemies until the arrival of humans and therefore did not need to develop flying wings.
这是因为人类到达这里之前,这些鸟没有天敌,因此,它们不需要发育飞行的翅膀。