Yesterday, Saturday, about 1 pm, the same (?) fledgling was at the place where Bob saw it, upstream from the bridge under the sawn-off stump on the left (looking upstream). The smaller, darker bird came and fed it. Then the fledgling flew further upstream, and the same adult came and fed it again.
Meanwhile the larger, lighter bird appeared with a mouthful of bugs, stopped below the bridge for a moment, then flew upstream past the first nestling and out of sight (to feed a second one?).
Later, when I was walking back down the path, I saw the lighter, larger adult fly by me, heading downstream, and heard (didn’t see) another (third?) fledgling being fed.
Seems like we might still have 3 fledgling!