The Great Crested Grebe family were at the southeast corner of the Serpentine island, invisible behind the wire baskets. But is was clear that they were there, because the father arrived carrying a small fish, swimming alternately above and under water to confuse any predator that might the following him, and dived under the basket to get to his family. These floating baskets sometimes break loose from their moorings and have to be towed back and refixed.

In another part of the lake, a grebe could be seen swimming under water, looking for food among the algae. In this picture the bird looks impossibly long and thin because of the refraction in the water -- though they are very slim and streamlined in reality.

After a while, the grebe swam along the shore to get to a better fishing ground, at an underwater cruising speed of 4 mph, so that I had to walk briskly to keep up. They exceed this speed when chasing fish, though I would not like to estimate how fast they can go.

Large wire baskets full of brushwood are being sunk in various places in the Serpentine. Earlier, bundles of the same kind of brushwood were put in the water all round the edge of the island. I spoke to one of the men doing it, and he said that the idea was that the twigs would be colonised by beneficial microorganisms that would clean the water. It can't do any harm.

While I was feeding some Coal Tits off my hand, a Goldcrest turned up and showed interest, though it didn't summon the courage to come down. It would be very pleasing to be able to attract these tiny birds. Even the Coal Tits only started coming to the hand this year. Now they are very bold, though they have to wait until the larger birds have had their turn.

While people were feeding the cygnets of one of the Mute Swans, a Carrion Crow tried to grab some of their food. The mother swan saw it off.

There was a Blue Tailed Damselfly among the wild plants near the bridge, mixing with the Common Blues that I illustrated earlier.