A cuckoo finished one of the longest migrations by a bird. The cuckoo left its winter home in Zambia in March and flew to Mongolia. Scientists named the bird Onon, after a Mongolian river. They micro-chipped five cuckoos last summer to track their migration and monitored the birds across the Indian Ocean and Asia. Onon was the quickest to make the journey from Mongolia to Zambia and back. The scientists called it "a mammoth journey".
The tagging was a joint venture between Mongolian, British and Chinese scientists. They set up a blog called the Mongolia Cuckoo Project for bird lovers to see the birds' progress. Onon arrived home on May the 27th after flying 26,000km. The blog said it was: "Remarkable navigation and endurance." It added: "Onon has no time to waste as he needs to set up his territory, defend it from competing males and mate with as many females as possible."