First report and breeding record of the Chinese Crested Tern Thalasseus bernsteini on the Korean Peninsula

Abstract The Chinese Crested Tern Thalasseus bernsteini is a critically endangered species (as designated by the IUCN (International Union for Conservation of Nature and Natural Resources). This report expands the known breeding grounds of these birds eastward. An individual of the Chinese Crested Tern was first observed at an uninhabited island of Jeollanam-do in Korea on April 28, 2016. On May 9, 2016 five Chinese Crested Terns (consisting of 2 breeding pairs and a single bird) were observed. Nests from the breeding pairs were found, at a distance of 0.6 m from each other; each pair was observed incubating one egg in the nest. To our knowledge, this is the easternmost record of breeding grounds for the Chinese Crested Tern.