Japanese Marsh Warbler Locustella pryeri wintering in Chiba Prefecture and Lower Tone River of Japan

Abstract

The survey of wintering Japanese Marsh Warbler Locustella pryeri was conducted at 37 wet grasslands within Chiba Prefecture and Lower Tone River of the Kanto Region from late December to mid-February in three winters (2014-2017). We located 338 individuals at 27 survey sites. Abandoned rice fields were one of the most important environments: they had the most wintering sites and populations. The birds were located in various types of grassland, suggesting that they can use some vegetation structures for wintering.