I saw and heard five Goldcrests in various parts of the park, including one at the Rima relief.
The Moorhen still occupying the old Coots' nest in the boathouse seems to be alone. Probably it sees the pile of twigs as just a place to retreat, rather than a nest.
The Mute Swans on the Long Water are definitely preparing to nest on their new artificial island. They were pulling up reeds to make a comfortable place to sit.
The Great Crested Grebes' nest near the bridge is still occupied, here by the male while the female went fishing under the bridge.
However, I think it most unlikely that this breeding attempt will succeed. It depends on there being enough small fish to feed the young, but the fish in the lake haven't spawned yet, and the one-year-old fish are already too large for baby grebes. Little Grebes can get round this problem by shaking fish so violently that they come to pieces, but Great Crested Grebes don't seem to have caught this useful idea.
The Scaup was on the north side of the Serpentine again, having a preening session.
A Great Spotted Woodpecker was pecking idly at a tree in the leaf yard, not yet intending to excavate a nest hole.
Africa Gómez has a good picture on her blog, The Rattling Crow, of a Great Spotted Woodpecker caught at the moment its head actually strikes the wood. It has its eyes shut. Woodpeckers not only have a special energy-absorbing skull to guard them from brain damage, they also have strong eyelids to stop their eyes from popping out.
As far as I know, no one saw the male Tawny Owl today. Does his recent move to the beech tree, and his absence today, mean that the owlets are coming out? If he's absent tomorrow, it's time to start looking for them.
The female Little Owl was in the chestnut tree just up the hill from her nest tree, and allowed herself to be photographed.
It was only when someone came past with two noisy little dogs that she retreated into her hole.