Possible ID for consideration. The sound recorded just before the bird took off (flight call?). At the time of the recording, the bird was hidden, but it appeared after this sound. There were not so many birds in the field and the voice does not resemble the voice of the species (such as herons and ducks) recorded on the day (according to visitors). Although I have not been able to find the online resource for direct comparison, I present this recording for consideration. Please make a comment if the voice can be identified with a different species (there may have been other hidden species). Although this species is usually referred to be mostly silent when wintering, there is a description on this page http://fuku-fuku106.cocolog-nifty.com/blog/2007/12/post_9fc9.html that this species repeated the voice tender 'kuhah' (translated from Japanese character expression), which reminded the author of some kind of a duck. I wonder if this type of voice corresponds to the present recording. The bird was juvenile, with a black patch at the tip of the wing. It was actively feeding and sometimes flew. Just for information, there is a YouTube video of a calling captive bird (this voice is totally different). https://www.youtube.com/watch?v=bpN2Yab4-2w

bird-seen:no

playback-used:no