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This paper presents bird records from the Kingdom of Tonga which do not fit into other publications about the extensive field work of the Brehm Fund South Seas Expedition. Results of the first ornithological survey of the small island of ‘Eua’iki are presented. Most remarkably, this island has small numbers of Vini australis and Clytorhynchus vitiensis, which became extinct on ‘Eua and Tongatapu at the end of the 19th century. Other new distribution records for C. vitiensis are presented, and the record of its distribution in Tonga is revised. Its absence from the larger islands in southern Tonga is a result of human disturbance, most likely the introduction of Rattus rattus, while in the Vava’u group, competitive exclusion by Pachycephala jacquinoti may be the reason. Hirundo tahitica is now known from many locations. Breeding colonies seem to exist on Tofua and Nomuka, and a breeding population is probably establishing on ‘Eua. A few new data are added to the sparse knowledge about Pachycephala jacquinoti. Ardea novaehollandiae was recorded again from Tongatapu and Circus approximans for the first time from Tongatapu and Niuafo’ou. Records of Prosopeia tabuensis from Tongatapu and two of its offshore islands are given, and some remarkable changes in behaviour of Porphyrio porphyrio on small islands are reported. The brown female morph of Gallicolumba stairii, which has been known from Fiji and Samoa, is also in Tonga. An unidentified storm petrel has been seen close to Tongatapu. Breeding has been confirmed for Pterodroma nigripennis and Sterna sumatrana on several islands in the Tongatapu group. Some new breeding records for noddies (Anous spp.) on islands off Tongatapu are presented. Observations of Procelsterna cerulea on ‘Eua suggest that the species breeds in the cliffs of the east coast. Sterna anaetheta certainly breeds in cliffs on the southern coast of Tongatapu. The discovery of new breeding colonies of Pterodroma nigripennis supports the hypothesis that the species is extending its range. Blue-crowned Lorikeets and Fiji Shrikebills have been isolated on ‘Eua’iki for more than a century. These populations, and others, are very small (fewer than 100 birds each). Their size and long isolation call into question the concept of Minimum Viable Populations.