Tim writes: the Collared Crow used to be common over large areas of lowland, rural China, just creeping into Vietnam. But its numbers have tumbled over the past 15 years and is now only found commonly in a few areas in its former range. Places that used to support hundreds of birds are now down to single figure counts. This link is thought to be related to agricultural intensification, particularly the use of pesticides. They forage a lot in the rivers and the widespread use of biocides has reduced their invertebrate and vertebrate prey. They are now classed as near-threatened but the decline is continuing so they are likely to be upgraded. We only saw small numbers along the river in an agricultural area near Tangjaihe in Sichuan.