So today I went over to Burwell Fen to see if I could find any of that little flock, and pretty much straight away got one in the shallows, seen indistinctly in the middle of the crappy photo below.
A pair of marsh harriers were active over one of the more southerly reedbeds and as I watched they were joined by two young who flew with them for a few minutes before settling back into the reeds, which I thought was pretty good. A sedge warbler came and sat in the bushes next to me then played hide and seek for a few minutes while I tried to get a good look. It's call got fainter and fainter until I was sure it had moved away, then when I stood up it flew out from right in front of where I had been sat. Clever.
A kingfisher flew up the bank and over me, about five yards from my shoulder, giving me one of the best views I've had of one. I thought I'd had all I deserved until this female yellow wagtail came and posed for me as I was packing up.