We did see both a Peregrine and a Sparrowhawk, both too far up for anything but wretched pictures.
The best sighting was of a Goldcrest seen from over the bridge parapet in the trees below, the unusual top view showing off its crest well.
A Long-Tailed Tit was gathering lichen for its nest.
There were several Pied Wagtails. This one was beside the Round Pond.
A Song Thrush flew over the path near Peter Pan and vanished into a bush. It was visible later in the leaf yard.
There were a lot of Stock Doves, this one near the leaf yard. They are easy to miss, as they look very like Feral Pigeons that happen to be the same colour. But their dark eyes are distinctive, unlike the dull orange eyes of Feral Pigeons.
The day, which had started quite fine with occasional sunshine, got darker and windier, and a group of Red-Crested Pochards were bouncing up and down on the choppy waves at the east end of the Serpentine.
The pair of Mandarin which have been on the Serpentine for some days have now come right up to the east end. The drake was preening his elaborate plumage. Each of the 'sails' on his back is a single very wide feather which needs careful maintenance.
The Great Crested Grebes at this end of the lake were displaying, and then had another disastrous attempt at a dance -- only one of them dived to pick up some weed while the other just sat there. They really do need to practise.
The pigeon-killing Lesser Black-Backed Gull glided inshore to try to grab a pigeon. I don't think he has ever caught one by flying at it, as pigeons are too fast and agile. But the Saturday crowds on the shore made his usual hunting method difficult.
The Egyptian Geese at the Round Pond had completely lost the plot, and were wandering around aimlessly leaving their brood unprotected. Luckily the Carrion Crows were elsewhere, and there were only a handful of big gulls on the other side of the pond.
In spite of the poor weather, a terrapin had hauled itself up on the fallen horse chestnut tree in the Long Water. Usually they only come out to bask in sunshine. This picture was taken from Peter Pan. Usually they are on the other side of the tree and can only be seen from the Italian Garden.