The subspecies of Chlidonias hybridus (Pallas), their breeding distribution and migrations

CONTENTS 1. Introduction ... 3 2. Bartels collection from Java (GCAJ) ... 4 3. Specimens from Ceylon (GCAJ) ... 6 4. Additional material from the Greater Sunda Islands and from the Philippines ... 7 5. Status in the Indo-Australian region ... 8 6. Status in East Asia ... 15 7. Status in Africa ... 17 8. Western Palaearctic breeding distribution ... 23 9. Geographical variation ... 34 10. Measurements ... 38 11. Breeding season and nuptial plumage ... 41 12. The identity of Sterna javanica Hors field ... 45 13. Nomenclature ... 46 14. The systematic position of Hydrochelidon albostiata Gray ... 49 15. Acknowledgements ... 53 16. References ... 54 I. INTRODUCTION During the years preceding his sudden death in Januari 1962, my predecessor, Dr. G. C. A . Junge, was engaged in a broad study of the birds of Java. This study was mainly based on the excellent Bartels collection, purchased not long before, but Junge included other material and also used the manuscripts and diaries of M . E . G. Bartels, which had been received with the collection. In his accustomed meticulous way, strictly following the "Peters" sequence, Junge has measured and studied every specimen, from the Podicipedidae to the Columbidae, measured their eggs, and noted particulars of breeding, moult, food, etc. Unfortunately, the manuscript as a whole is too incomplete to justify its publication: it is in the form of rough notes and they are evidently no more than a basis from which later a definitive text was to be compiled. Also, the publication of large series of localities and measurements of common species, about which there is no systematic problem requiring such detailed information, would be of little interest. Information on eggs contained in the Bartels collection and on breeding-seasons as deduced from them, has in the meantime been published separately by Hellebrekers & Hoogerwerf (1967).