Certain shorebirds depend on these eggs for food during their annual spring migration to their northern breeding grounds.

某些海鸟在每年春季迁徙到北方繁殖地时，以这些鸟蛋为食。

youdao

What we've shown is that there are three clear migration routes as they head back to feeding grounds after breeding in Gabon, although the Numbers adopting each strategy varied each year.

我们所能得到的结果是他们在加蓬反之后返回觅食区的路径有三条，尽管他们的数量逐年发生改变。

youdao

'What we've shown is that there are three clear migration routes as they head back to feeding grounds after breeding in Gabon, although the Numbers adopting each strategy varied each year.

我们所能得到的结果是他们在加蓬反之后返回觅食区的路径有三条，尽管他们的数量逐年发生改变。

youdao

The tech will be used to map walrus migration patterns and breeding grounds.

FORBES: For Walrus Wary Russian Oil Drillers, WWF Turns To Space

Another theory is that the birds may have fallen victim to hunting, development or changes in farming along their 6, 000km (3, 600 mile) migration route to breeding grounds in the Russian Arctic.

BBC: Red-breasted goose