So maybe, there are 12 billion, we lost 3 billion breeding birds.

所以，也许有 120 亿只，我们失去了 30 亿只繁殖鸟类。

In late spring, the chilly lake waters are a magnet for breeding birds.

春末寒冷的湖水，吸引了大批来此繁殖的鸟类。

Hobbyists began breeding the birds for show.

爱好者开始繁殖鸟类进行表演。

Ancient trash dug up by archaeologists tells us about two thousand years ago a few Native American cultures realized breeding birds in captivity is easier than chasing them through the forest.

考古学家挖掘出的古代的垃圾告诉我们，大约两千年前，一些美洲土著意识到圈养鸟类比在森林里追逐它们要容易。