Star bird of this visit - well I would have said the spotted redshank, but see below....As I approached the rapidly drying up open water I disturbed a medium sized wader - a shrill chew-it , got the bins on it, yes, a spotted redshank in winter plumage. It dropped back onto the mud, but flew again half a minute later, circled and flew off up the Corse, calling the while, dropping again around the upper end of the reeds. It was the only wader present apart from a few snipe and the displaying pair of lapwing. Still plenty of teal flying about in small groups (perhaps 100-150 in all), mallard, 5 shoveler (3m2f) who seem firmly attached to the remains of the open water. A pair of greylags in view on the mud, at least two more birds were honking away somewhere in the reeds. 
A pair of wheatears were present at the edge of the fen meadow, 3 widely separated Cetti's singing. 
But - scanning the reedbed on the return leg, about 200 metres upstream of Starman's Hall, the briefest of glimpses of a small brown waterfowl with distinct, large pale buffish-brown wing patches which rose just above the reeds and dropped straight back again. Had I been where I'm going in May I would have thought probably a female little bittern. Not claiming it, just alerting the other regulars to the possibility!
The NT is working on access arrangements to the Corse, watch this space.