Until this year, there were only two known breeding colonies of the Critically Endangered Chinese Crested Tern Sterna bernsteini: the Mazu Islands off the coast of Fujian, and the Wuzhishan Islands off Zhejiang.
However, this summer an innovative tern colony restoration project has apparently established another.
Earlier this year, a small island called Tiedun Dao in the Jiushan Islands – an archipelago where Chinese Crested Terns used to breed – was chosen for colony restoration. The restoration team expected it would take some years before there was any hope of attracting the birds back. Their plan was to use decoys and playback tern calls to initially attract Great Crested Terns Sterna bergii to Tiedun Dao. It was hoped that the Great Crested Terns would initially colonise the island, their numbers would then gradually grow, and that Chinese Crested Terns, which have always been found nesting within large colonies of Great Crested Terns, might eventually follow too.
Yet by late September, and at the first attempt, a substantial new colony of Great Crested Terns had arrived on Tiedun Dao, raised hundreds of young and, among them, at least one Chinese Crested Tern chick (below) also successfully fledged.
In early May 2013, a team from the Xiangshan Ocean and Fishery Bureau, the Jiushan Islands National Nature Reserve, the Zhejiang Museum of Natural History and Oregon State University cleared vegetation and placed 300 tern decoys on Tiedun Dao. Solar powered playback systems were installed among the decoys broadcasting contact calls of Great and Chinese Crested Terns from the Wuzhishan Islands colony.
A few Great Crested Terns visited during the first week in June and showed some initial nesting behaviour but only stayed a few days. This alone was considered a successful first season for the project. With no further signs of any visiting birds in the following five weeks, the breeding season was thought to be over and monitoring was suspended.
When another international team including members from BirdLife International, the Hong Kong Bird Watching Society, the Oregon State University, the Zhejiang Museum of Natural History and the Jiushan Islands National Nature Reserve visited in mid-July, they restarted the playback system. To their surprise and delight, almost immediately a few Great Crested Terns were attracted in and were seen flying above the decoys. Their numbers grew to several hundred within a few days and by the end of July a high count of 2,600 Great Crested Terns had been recorded and hundreds of pairs had laid eggs and begun incubation. Among them were 19 adult Chinese Crested Terns – the highest single count since the species’ rediscovery in 2000. At least two pairs also laid eggs and initiated incubation. Despite typhoons, that made further monitoring difficult, by late September approximately 600 Great Crested Tern, and at least one Chinese Crested Tern chick, had successfully fledged.
Commenting on the recolonisation project, Mr Yu Mingquan, Deputy Director of the Xiangshan Ocean and Fishery Bureau, who is very pleased with its success, said, “We will do our best to ensure good management of the Jiushan Islands National Nature Reserve and we also hope to receive more support for the conservation of the tern colony here in Xiangshan.”
“The success on Tiedun Dao is a landmark for contemporary conservation in this region.” responded BirdLife’s Senior Asia Conservation Officer, Simba Chan. “No one dared imagine that the first year of such a challenging restoration project would be so successful, it just goes to show what can happen with a good idea, strong local commitment and a bit of luck.”
Jim Lawrence, BirdLife’s Preventing Extinctions Programme Manager, also commented, “This is a wonderful example of the conservation success that can be achieved through coordinated international collaboration when it is backed by solid science, local enlightenment and strategic funding support. Congratulations to all concerned.”
This BirdLife Preventing Extinctions Programme project is sponsored by several international funders including the Japan Fund for Global Environment, the US Fish and Wildlife Service (Wildlife Without Borders), the Ocean Park Conservation Foundation Hong Kong and BirdLife International supporter – Mark Constantine. In China, the Xiangshan Ocean and Fishery Bureau, the Jiushan Islands National Nature Reserve and the Zhejiang Museum of Natural History provided vital match funding. These three Chinese organisations also coordinated conservation action in China and provided significant logistical support there that helped make the first year of the project such a resounding success.