Siberian chiffchaff to be a full species due to its distinctive plumage and vocalisations, being similar to "P. s. sindianus" in these respects. Common chiffchaffs (of the nominate race) and Siberian chiffchaffs do not recognize each other's songs. Pending resolution of the status of the form "fulvescens", which is found where the ranges of common chiffchaff (of the race "abietinus") and Siberian chiffchaff connect and may or may not be a hybrid between these, "tristis" is maintained in "P. collybita" by most checklists. Siberian chiffchaff Siberian chiffchaff ("Phylloscopus (collybita) tristis") is a leaf-warbler which is usually considered a subspecies of the common
Handbook to the Birds of Australia says in his Preface: ”Nearly twenty years have elapsed since my folio work on the Birds of Australia was completed. During that period many new species have been discovered, and much additional information acquired respecting those comprised therein; consequently it appeared to me that a careful "résumé" of the entire subject would be acceptable to the possessors of the former edition, as well as to the many persons in Australia who are now turning their attention to the ornithology of the country in which they are resident. Indeed I have been assured that such a work is greatly needed to