Number and Distribution Records of Caspian Tern Hydroprogne caspia in Indonesia, with Special Reference to Sumatra

We summarize all reports of Caspian Tern Hydroprogne caspia recorded in Indonesia, with particular focus on Sumatra (1983–2019). There were 29 records in total, which together indicate that the Caspian Tern is a regular visitor to Indonesia, in contrast to previous assumptions that it is rare. This species has been recorded during the non-breeding period (September to March in Indonesia, and August to April in Sumatra) in small numbers ranging from one to 40 birds. Many potential sites for this species, particularly along east coast of Sumatra, have still not been well explored. Additional search efforts will advance our knowledge of Caspian Tern and other seabirds that occur in Indonesia.