3 . Scientists have been surprised and impressed with the long-distance travel of two birds recently, a common cuckoo which flew from southern Africa to Mongolia, and an eastern curlew, which flew from Australia to China.
On one is a common cuckoo. It's one of 5 cuckoos who were tagged last summer in Mongolia? far to the north of China. 1 However, scientists weren't sure that cuckoos from Mongolia flew to Africa for the winter.
In June, 2020, scientists attached tiny trackers to five cuckoos. 2 Sure enough, Onon spent the winter in southern Africa — in Zambia.
3 “It was one of the longest animal migrations which has been recorded for a land bird.” said Chris Hewson, one of the project s lead scientists.
At times, Onon stopped for a few hours or a few days. But some of the long stretches, like crossing the Indian Ocean, had to be done without stopping. 4 The birds have to travel through strong winds and storms, make sure they find enough to eat, and avoid being eaten themselves.
Luckily, cuckoos seem to have a good sense of weather patterns, allowing them to fatten up as much as possible right before they leave. They also seem to be good at finding helpful winds that allow them to travel long distances without getting too tired. 5 Onon is the only one of the five tagged cuckoos who made it all the way back to Mongolia.
| A．All of them grew well. |
| B．Still, flying such long distances isn't easy. |
| C．Long migrations like this are dangerous. |
| D．Cuckoos originally came from Africa. |
| E．They broke previous records of animal migrations. |
| F．Long migrations are common among sea birds, but cuckoos are land birds. |
| G．These trackers allowed the scientists to follow the movements of the birds on a map. |
