Sedge Warbler - with a call like a cat on heat you'll know immediately that they are around. You see them a lot, too, darting through the air in and out of reeds, but they're reluctant photo subjects. I've not yet been able to get a really good picture of one, this is a heavy crop taken during my test of the M1X. Maybe I could have gotten a tiny bit more detail with the Nikon 500 but I'm not sure I would have gotten a shot off in the first place. M1X/300mm f/4.