Discovery of ten new specimens of large-billed reed warbler Acrocephalus orinus, and new insights into its distributional range

摘要

We here report the finding of ten new specimens of the poorly known large-billed reed warbler Acrocephalus orinus. Preliminary identifications were made on the basis of bill, tarsus and claw measurements, and their specific identity was then confirmed by comparison of partial sequences of the cytochrome b gene with a large data set containing nearly all other species in the genus Acrocephalus, including the type specimen of A. orinus. Five of the new specimens were collected in summer in Afghanistan and Kazakhstan, indicating that the species probably breeds in Central Asia, and the data and moult of the others suggest that the species migrates along the Himalayas to winter in N India and SE Asia. The population structure suggests a stable or shrinking population.