Night time noseying about

I went into a couple of reedbed areas in the brick pits after dark friday night. It was something I had meant to do for a couple of years but with mouth-watering SFY ticks possible such as Savis and Spotted Crake, it was long overdue and I will probably go in again later in the month.  Needless to say I did not get this pair but an estimated four pairs of squealing Water Rails were actually SF ticks for the year as my normal search places in the south in winter were both too dry to hold any of them. One pit had a singing Nightingale continuously for an hour and Barn and Tawny Owls also heard. Now I am wondering what was that heron sp. that I flushed from the reeds in the early hours of this morning ?