One of the Great Crested Grebe chicks on the Long Water had climbed on to a Coot's nest and was lying down on it, when another swam past with a fish that it had caught itself.
They then started to play mothers and fathers on the nest, building it up with twigs and bits of weed and shaking their heads at each other in the adult greeting gesture.
But their devoted parents are still feeding them.
Gulls play even when they are adults, and this one on the Serpentine was amusing itself by throwing a leaf and a stick around.
The female Pied Wagtail was walking along the railing of the Lido restuarant looking at the tables which had people at them to see if there were any scraps worth seizing.
It also ran around under the tables, calling loudly. The people were amazed by the boldness of this little bird, and no wonder.
The Reed Warblers are still in the reed bed near the bridge.
The female Little Owl was more visible than usual in this year's nest tree.
Later she shifted to the other chestnut tree and sat where the male owl usually sits. There was no sign of him.
Near the Lido restaurant, a Mallard drake had been making advances to a female. She was having none of this, and attacked him and chased him off.
This might seem like an amusing picture of a rat taking no notice of an inquisitive Mallard, but it isn't.
The rat, which had come down to the lake to drink, was listless and clearly ill, and had difficulty climbing back up the kerb to return to the shrubbery. It looks as if the park staff have been putting down rat poison again, gravely endangering the other park wildlife. Even if the other creatures can't get to the poisoned bait, predators will eat the rats and be poisoned themselves.