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 of the Birds of the World to Scientific Names in Ornithology'. A list of volumes of the "Handbook of the Birds of the World" produced to date is as follows: This volume was published in 1992. Unlike subsequent volumes, it does not have an introductory essay; instead, it has a 38-page overview by Eduardo de Juana of the biology of birds and a foreword welcoming the HBW project, by Christoph Imboden. Groups covered in this volume are as follows: This volume was published in 1994. It has a foreword by Walter J. Bock on the organization of information in HBW. Groups covered in this volume are