BEIJING -- Chinese poets have often employed the cuckoo's arrival as a symbol for a call to return home, but few knew where the bird had come from.

Technology now has the answer. Satellite tracking has shown the common cuckoo can travel up to 12,000 km between winter grounds as far away as east Africa and its summer home in Beijing.

Chinese and British ornithologists and bird lovers caught 16 cuckoos in three Beijing wetland parks in May, and fitted satellite tags to five birds.

Data showed that a male bird named "Skybomb Bolt" had completed a 3,700-km non-stop flight from central India, across the Arabian Sea, to Somalia earlier November, while two had flown to northern India, and the other two were lost.

It is thought to be the longest migration route known for any cuckoo and is much longer than that of the European cuckoo. "Before leaving India, he had already travelled nearly as far as some UK cuckoos do on their entire migration," says Chris Hewson, a researcher and member of British Trust for Ornithology.

"Watching how it has made the world look small is a fantastic and humbling experience."

Beijing cuckoos fly south in October and return in April. Though well-known for their distinctive call, the birds are very secretive. Shi Yang, a bird watcher for 10 years, says cuckoos usually perch in the dense tree canopy: "They are rarely seen unless they fly." As such, they are very difficult to study, confounding ornithologists who speculate on their flight paths. The population, breeding seasons and threats they face are still unknown.

Only in recent years have tracking devices become small enough for the birds to carry. In the past, satellite technology was only able to track bigger birds, such as red-crowned cranes and whooper swans.

"In the future, when technology advances, we hope to track different, smaller birds too," says Terry Townshend, an organizer of the project and founder of the Birding Beijing NGO.

Townshend, a Briton who has been bird-watching in Beijing for five years, boasts how schools have participated in the project, broadening its impact beyond traditional science circles.

He frequently visits schools, gives lectures and leads school bird-watching trips. Students can follow the cuckoos' progress and learn more about their habitat.

In August, Beijing middle school students, who were studying the Olympics at the time, named "Skybomb Bolt" after the champion sprinter Usain Bolt.

Illegal netting of migratory birds has been frequently reported in China this year, reinforcing the importance of public engagement.

"People want to protect what they love, but they can only love what they know. It's important to tell more people about the incredible journeys. When people learn about the cuckoo, they want to protect it."