Cuckoo completes one of the longest migrations ever recorded by a land bird with 7,500-mile flight from Zambia to Mongolia

• The cuckoo, named Onon after Mongolian river, flew from Zambia to Mongolia
• It set off in March and has now arrived at its breeding ground
• The bird flew through 16 countries and across the Indian Ocean on its journey
• Was part of study by British Trust for Ornithology (BTO) and scientists

A cuckoo has completed one of the longest migrations ever recorded by any land bird. 

Scientists have been monitoring the progress of the cuckoo, named Onon after a Mongolian river, which has just flown more than 7,500 miles (12,000km). 

Its starting point was in Zambia, in southern Africa, and it has now arrived at its breeding ground in Mongolia. 

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A cuckoo has completed one of the longest migrations ever recorded by any land bird. Scientists have been monitoring the progress of the cuckoo, named Onon after a Mongolian river, which has just flown more than 7,500 miles (12,000km)

The hardy bird's route meant it had to fly 1,600 miles across the Indian Ocean without stopping.

It also flew across 16 countries, surviving high winds in the process, the BBC reported. 

Onon, a common cuckoo (Cuculus canorus) was satellite-tagged before it set off from its winter home in Zambia on March 20. 

It has flown at an average speed of 37mph (60km/h) over countries including Kenya, India and Bangladesh. 

A second bird which also set off from Zambia, named Bayan, got as far as Yunnan in China before either dying from exhaustion or being killed for food.

Bayan had flown more than 6,000 miles (10,000km) in just two weeks and scientists believe he may have been too exhausted and hungry to stay out of danger.  

Both birds were part of the Mongolia Cuckoo Project, a joint study between the British Trust for Ornithology (BTO) and scientists looking at long-distance migration.

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 Its starting point was in Zambia, in southern Africa, and it has now arrived at its breeding ground in Mongolia (file photo of a cuckoo)

In total, five birds were tagged but Onon is the only one to have survived its journey. 

The BTO's Dr Chris Hewson told the BBC that the distance and speed at which Onon had travelled showed that cuckoos are finding ways of fattening up before their trip and know exactly where to find 'favourable wind conditions' to help them. 

Cuckoos in the UK usually leave for their migration June. The birds are known for laying their eggs in the nests of other birds. 

The baby cuckoo then hatches before the eggs of the host birds and pushes them or hatched babies out of the nest. 

The host parents continue to feed the young cuckoo, even once it has grown much larger than them. 

Land birds are those which spend their lives on land rather than at sea.  

According to the RSPB, around 40 per cent of the world's birds regularly migrate  between countries.  

The record for the longest continuous flight without stopping is held by a female shorebird which flew 7,145 miles (11,500 kilometres) from Alaska to New Zealand in 2007.  

It was tracked by a tag attached to its leg which did not affect its flight.