The only activity I saw on the owls' nest tree was a pair of Ring-Necked Parakeets courting. The female was clearly enjoying the attention.
The Grey Herons really do seem to have abandoned their attempt at nesting. There was an Egyptian Goose in one of their half-finished nests, and a heron stood on the shore completely indifferent to the intruder.
The Egyptian would not have been trying to use the nest for itself. It was just indulging its habit of standing around in trees, which these birds do all winter long before they think of nesting.
The Coot nest offshore from Peter Pan is now definitely established, and has been occupied every time I have gone past it.
All four Jackdaws were flying around near the Speke obelisk. There is a lively rivalry between the Carrion Crows, Magpies and Jackdaws in this area, and at one point the Jackdaws attacked a solitary Magpie and chased it away.
Both Little Grebes came past the Italian Garden, though I only managed to see one of them on a second visit. They are constantly moving around the edge of the lake and you have to be lucky to catch one in a visible place.
Update: Elizabeth saw the Tawny Owl at 5.30 pm in his usual place. So he was just spending the day indoors.