Every spring, migratory birds flood back to where they breed.

每春天，候鸟都会涌回它们繁殖的地方。

People liked eating the migratory birds, and they disappeared from Europe.

们喜欢吃候鸟，于是它们就从欧洲消失了。

Cryptochrome has been found in the eyes of several migratory birds.

们在一些候鸟的眼睛里发现了隐色体。

The Nordic countries provide a home to millions of migratory birds.

北欧地区是数百万候鸟的容身之地。

And migratory birds that extend their visits may provide competition for some avian natives.

同时，逗留时间更长的候鸟也可能对一些本土鸟产生竞争。

Temperatures begin to cool and migratory birds set off on their southward journeys.

温渐凉，候鸟踏上南的旅程。

If you want to help protect migratory birds, go to BirdCast.

如果您想帮助保护候鸟，请访问 BirdCast。

It has also become a popular stopover for a large number of migratory birds.

同时，对很多的候鸟来说，它也变成一个受欢迎的中转站。

For several months until mid-November it recorded the night-time calls of migratory birds flying above.

在11月中旬之前的几个月里，它记录了夜间鸟类时在空中飞行的叫声。

But also that scale is shrinking as migratory bird populations decline to record low numbers.

但随着候鸟数量下降至历史低，规模也在缩水。

Migratory birds navigate to their summer and winter homes by way of the moon and stars.

候鸟通过月亮和星星的指引飞往夏季和冬季的家园。

So the thought that people would make a connection between light pollution and migratory birds seems unlikely.

因此，们似乎不太可能把光污染和候鸟联系起来。

Some 200,000 migratory birds fly to Duchang during winter, with the peak migratory season falling in November.

大约 20 万只候鸟在冬季飞往都昌，11 月是候鸟的高峰期。

The wetlands near the head of the canyon are an important wintering site for many migratory birds.

大峡谷起附近的雅江湿地是许多候鸟的重要越冬地。

Every Spring and Autumn, nearly 3 million migratory birds around the world stop here to replenish themselves.

每个春天和秋天，全世界的将近三百万的鸟儿停驻在这里，为自己补充能量。

Migratory bird shuttling between the Chinese mainland and South Pacific Islands use the site as a rest stop.

而来往于中大陆和南太平洋岛屿间的候鸟便将这个岛屿当成了休息的驿站。

Things tend to not look amazing for migratory birds right now.

对于候鸟来说，现在的情况并不乐观。

Fritz said the group's work is the first attempt to reintroduce a continentally extinct migratory bird species.

弗里茨说，该小组的工作是首次尝试重新引入大陆灭绝的候鸟物种。

These migratory birds traveled South from Northern states and Canadian provinces when migrating, but overhunting made them increasingly rare.

这些候鸟从北部各州和加拿大各省到南方，但过度捕猎使它们越来越少。

More habitats for migratory birds are appearing as the environment improves, added Li in an interview with China Daily.

李志军在接受《中日报》采访时补充说，随着环境的改善，候鸟的栖息地越来越多。