Siberian chiffchaff Siberian chiffchaff Siberian chiffchaff ("Phylloscopus (collybita) tristis") is a leaf-warbler which is usually considered a subspecies of the common chiffchaff, but may be a species in its own right. Siberian chiffchaff breeds in Siberia east of the Pechora River and winters in the lower Himalayas. It is also regularly recorded in western Europe in winter, and it is likely that the numbers involved have been underestimated due to uncertainties over identification criteria, lack of good data and recording policies (Sweden and Finland only accept trapped birds). Because of their unfamiliar appearance, British records in the 1950s and 1960s were originally
Common chiffchaff collisions with windows, buildings and cars. Only the first of these has the potential to seriously affect populations, but given the huge geographical spread of "P. c. abietinus" and "P. c. tristis", and woodland conservation policies in the range of "P. c. collybita", the chiffchaff's future seems assured. The common chiffchaff has an enormous range, with an estimated global extent of 10 million square kilometres (3.8 million square miles) and a population of 60–120 million individuals in Europe alone. Although global population trends have not been quantified, the species is not believed to approach the thresholds for the population decline