For example, frigate Birds spend days flying over the ocean looking for food.

例如，军舰鸟花几天时间在海洋上飞行寻找食物。

With food so hard to come by in the open ocean, newly hatched sooty tern chicks are easy pickings for the larger frigate birds.

在海洋中寻找食物是如此的困难，刚出壳的乌燕鸥，对大一些的军舰鸟来说，就是垂手可得的食物。

While tropic birds can survive at sea for months on end, others, like frigate birds, return to roost every night, so are a sure sign of nearby land.

热带的鸟能连续在海上生存数月，其他的，像军舰鸟，每天晚上会栖息地，这是附近存在陆地的信号。