A cuckoo has just finished one of the longest migrations ever by any bird. The cuckoo left its winter home in Zambia on March the 20th and reached its breeding ground in Mongolia. Ornithologists called the bird Onon after a Mongolian river. The scientists micro-chipped five cuckoos in Mongolia last summer to track their migration. The tags monitored the birds across the Indian Ocean and 16 countries. Onon was the quickest to make the return journey from Mongolia to Zambia and back. The scientists were amazed at Onon's feat. They called it "a mammoth journey".
The tagging was a joint venture between the Wildlife Science and Conservation Center of Mongolia and the British Trust for Ornithology. The group Birding Beijing also helped. A blog called the Mongolia Cuckoo Project was set up for bird lovers to see the birds' progress. It reported that Onon arrived home after 26,000km, and 27 border crossings through 16 countries. It called the journey: "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."