Social attraction techniques were developed by Dr. Stephen Kress (Vice President for Bird Conservation, National Audubon Society [BirdLife USA]) for the restoration of Puffin colonies in the USA in 1970s, and has proven to be effective in restoring colonial seabird breeding sites. Since 2013, the adaptation of these techniques by Chan and colleagues has successfully restored the deserted Chinese Crested Tern breeding colony of the Jiushan Islands, leading to a record-breaking number of Chinese Crested Terns being found there (over 50!) during Chan’s protective stake-out seasons, doubling the known population at the time. This shows that the islands along the eastern China coast were highly disturbed (and perhaps even exploited) and so the terns congregated on the one island that had been made safe. Chan then recommended the use of social attraction to help the South Korean birds.
“I am pleased that social attraction methods have helped Chinese Crested Terns establish new colonies” said Dr. Kress. “This is good news for the species. Multiple nesting colonies within an expanded range reduces the risk of having most of the population in one location. Because each site brings its own risk to the species, multiple sites help to assure that some of the population will survive regardless of what happens at other colonies.”
"Exploitation and disturbance by humans are the main reasons for the failure of breeding," says Chan, "and I believe pollution is the main reason for embryos dying before hatching.” But there’s hope: “Unlike the southern breeding grounds, the coast of southwestern Korea is safe from human disturbance because the site is well-guarded. The pollution level is much lower too so it’s an ideal place for Chinese Crested Terns. Other potential risks, such as typhoons and hybridisation with Greater Crested Terns, will also be negligible at the site in Korea.”
The migration route of this mysterious bird still remains undiscovered, but the rediscovery of up to three Chinese Crested Terns at Panabo, Mindanao of the Philippines from 10 till 13 March 2018 has given tantalizing clues.
Plus if that wasn’t good news enough, Chinese Crested Tern have now also been spotted for the first time in Japan. On 20 October 2018, Dr Vladimir Dinets, a biologist teaching in Okinawa, took photos of Chinese Crested Tern while driving on the bridge linking the islands of Miyako and Irabu. “Given the vicinity of Japan to the Chinese Crested Tern’s current range, this discovery is long anticipated,” commented Chan. “But that doesn’t make it any less exciting! Also, the date of discovery might suggest that the post-breeding wandering stage of this species is quite long, meaning the potential success of using social attraction at new breeding sites is higher than previously expected.” If our work successfully continues, it looks like the puzzle of Where’s Wally for Asia’s rarest seabird could hopefully get a lot easier in the future.
The BirdLife International Chinese Crested Tern project is generously funded by the Ocean Park Conservation Foundation, Hong Kong; the Tilia Fund; the BirdLife Preventing Extinctions Programme; the National Geographic Society; and the Honk Kong Bird Watching Society (BirdLife in Hong Kong, China).
Thanks to Yu Yat-tung of the Hong Kong Bird Watching Society, Dr Park Jin-young and National Institute of Biodiversity Research of Korea, Dr Lee Kisup of Waterbird Network Korea for supporting and giving advice to the project, and Dr Kiyoaki Ozaki of Yamashina Institute for Ornithology in Japan for the discovery of Chinese Crested Tern in Japan.