The Goldeneye is back on the Serpentine. She was on the south side, near the place where people fish.
And the Scaup was on the opposite side near the bridge, so we have two unusual diving ducks at the moment.
A pair of Great Crested Grebes seemed to be building a nest on the island, at the west end. But closer inspection shows the large twigs of a Coots' nest, and almost certainly the grebes were just playing at building by putting their own nest material of soggy leaves on to it.
When it comes to competition for a site, Great Crested Grebes can chase Coots away, but the Coots return and win by sheer persistence.
Two more nests: Blue Tits are building inside their usual gas lamp post behind the Lido swimming area. Here one of them is bringing some grass.
Some of the park lamp posts including this one have a bulge in the cast iron column just below the top, and it seems that the birds are making their nest inside this bulge. Only Blue Tits use the lamp posts, as Great Tits are too large to squeeze past the gas pipe.
And the Long-Tailed Tits' nest that I first photographed on the 12th has grown considerably in four days. Here one of the pair is taking a moment's rest on top of the structure, looking unconcernedly at the camera.
Long-Tailed Tits are neither frightened of nor interested in people, they just ignore them.
Some Goldfinches were looking for insects in the moss on top of a wall at Kensington Palace.
The W-shaped thing at the back is four of the big revolving spikes that are supposed to stop you from climbing over the wall. I remember from my student days that these are usually rusted solid and immovable, so that they make convenient handholds and actually help you climb. Not that I would encourage my readers to an act of lèse-majesté.
There was a Green Woodpecker searching for worms in the long grass on Buck Hill.
The male Tawny Owl was in his usual place, preening.
When he had finished he uttered a quiet hoot. There is no need to shout, as his mate is in the nest only a couple of feet below him.