• Roseate Tern

    Roseate Tern ©Kenneth Lam Common name: Roseate Tern Scientific name: Sterna dougallii Local names:Розовая крачка (Russian), 粉红燕鸥 (Simplified Chinese), 粉紅燕鷗 (traditional Chinese), 긴꼬리제비갈매기 (Korean), ベニアジサシ(Japanese), Dara laut Dougalli (Indonesian), Camar Jambu (Malayu), Nhàn hồng (Vietnamese), นกนางนวลแกลบสีกุหลาบ (Thai) Conservation status: IUCN - Least Concern Roseate Tern is primarily distributed in tropical and subtropical seas. It is a strictly marine species. It is a specialized plunge-diver, feeding on small schooling fishes. There are three subspecies: S. d. dougallii, S. d. gracilis, S. d. korustes.     Identification Adult Roseate Tern ©Kenneth Lam Size: 33-41 cm; wingspan 72–80 cm. Body: medium-sized, very white-looking, with long tail-streamers. In breeding season, adults have a pinkish tinge to their underparts which gives them their name. Head: has a black cap which goes to the front of the base of the beak Beak: black beak with reddish base Legs and feet: reffish during breeding season, blackish in non-breeding season Juvenile: gray or buff above with some intermediates, barred with black chevrons The Roseate Tern is similar to the Common, Arctic and Forster's Terns, as they are medium-sized and grouped to ‘typical black-capped terns' of the genus Sterna. Distribution range Roseate Tern is widespread but breeding colonies sparely distributed along the east coast and offshore islands of Canada, U.S.A. down to Venezuela and Brazil, Caribbean, UK. France, Ireland, Portugal to Africa. In EAA Flyway, it breeds in South China Sea, Ryukyu Islands (Japan), Indonesia, Fiji, Solomon Islands, Papua New Guinea, and along coast of Australia. Wintering range is understudied. Habitat Breeding habitat The bird breeds on sandy, rocky or coral islands, with dense vegetation in temperate region, but mainly on barren islets in tropics. They primarily migrate offshore. Roseate Tern at breeding site ©Kenneth Lam Non-breeding habitat Little information but the bird is exclusively marine. Study with immersion sensors suggested they rest on water during daytime, indicating that they are feeding at sea and not resting on land between feeding bouts, but they rest on land during night time. Behavior Roseate Tern are diurnal species. They use aerial plunge-diving to catch food, often submerge briefly in water. At breeding colonies, frequently found at mixed colonies with other tern species, such as Black-naped Tern and Bridled Tern in South China and Southeast Asia waters. It spends much time bathing in shallow water close to shore. Population estimate Global estimated population: The global population is estimated to number c. 400,000-1,000,000 individuals. Its population in the EAAF is  c. 90,000 base on estimation of population of S.d. gracilis, Australia & Moluccas Is. Main threats Human disturbance, e.g. recreational and tourism activities at breeding sites Egg collection and chicks harvest Other threats: Plastic pollution Exotic predators Conservation Work Banding studies in Japan and Australia Roseate Tern at breeding site in Japan © Kiyoaki Ozaki/Yamashina Institute for Ornithology Roseate Tern at banded with engraved blue legflag in Japan © Kiyoaki Ozaki/Yamashina Institute for Ornithology Roseate Tern’s main breeding sites in Japan are in the Ryukyu Islands but in recent years some birds bred further north in Fukuoka, Osaka and Aichi. Banding of the terns has been started since 1975. A total of 11,981 birds were banded until 2020 and 391 Roseate Tern were recovered, which revealed their wintering site is in Swains Reef, Queensland Australia. Projects in Australia captured 368 Roseate Terns in July, 1999, 2000 and 2001, and 3044 in January of 2002 and 2003 in Swain Reefs. The study determined that at least some Roseate Terns bred on the Capricornia Cays in Australia. And it was the first evidence that Asian-breeding Roseate Terns over-winter in the southern hemisphere. Learn about the Japan bird banding report in 2020: https://www.biodic.go.jp/banding/pdf/banding_2020.pdf Fun Fact In 2002, the Japan Bird Migration Research Center compiled longevity records of Japanese birds based on research during 1961‒1995. From the reports with data collected during 1961‒2017, Roseate Tern holds a 23 years 11months record, the longest lifespan known so far.   Reference IUCN Red List: https://www.iucnredlist.org/species/22694601/132260491 Birds of the World: https://birdsoftheworld.org/bow/species/roster/cur/introduction Research papers: O’Neill Paul, Minton Clive, Ozaki Kiyoaki, White Rebecca (2005) Three populations of non-breeding Roseate Terns (Sterna dougallii) in the Swain Reefs, Southern Great Barrier Reef, Australia. Emu 105, 57-66. (https://doi.org/10.1071/MU03044) Yoshiyasu K, Morimoto G, Senda M, Nakamura N (2020) Longevity records of Japanese birds from bird banding data (top two records of each species in 1961–2017). J Yamashina Inst Ornithol. https://doi.org/10.3312/jyio.52.21 Gochang Big Bird Race 2023 brought birdwatchers to contribute bird data to the UNESCO World Heritage Site Special achievement award to the Chinese Crested Tern team Webinar on Chinese Crested Tern in the Yellow Sea and Seabird Conservation in China Chinese Crested Tern banded in Republic of Korea sighted in China Chinese Crested Tern Restoration of the Critically Endangered Chinese Crested Tern using social attraction technique A Conservation Success in Minjiang River Estuary A tern for the better Critically Endangered Chinese Crested Terns appear on a deserted island in South Korea The First Ever Banded Chinese Crested Tern Chick has Fledged

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