The Bearded Tits were flying restlessly up and down their usual reed bed near the Diana fountain, which made them easily visible. At the east end of the reeds the path curves down towards the lake, and I got within 6 ft of them without frightening them.

Every colour in the Phragmites reed head is represented in the bird's plumage, and even its typical attitude as it feeds follows the curve of the reeds. It blends perfectly into its surroundings.

On the Serpentine island, the Grey Heron that is building the nest was balancing precariously in the top of a tree, trying to pluck twigs. It had to use its wings to keep upright.

They seem to have quite a hard time breaking twigs off trees. It was there for five minutes without managing to detach one. Then it few into a birch tree, whose very slim twigs would have been easier to tackle. Presumably their large nests are made mainly of twigs that have already fallen off, which they pick up from the ground.

Some Black-Headed Gulls were doing their peculiar display in which they hold out their wings, raise their heads, and croon at each other.

Perhaps the position of the wings is intended to make them look larger, and therefore more attractive. Great Crested Grebes also have a courting display in which one of the pair raises its wings to increase its size, while the other stands up in the water and shakes its head ecstatically; this is known as the 'cat dance' because the sitting bird assumes the rounded shape of a sitting cat. But it seems likely that in this case the attitude may represent a parent grebe with wings raised to accommodate a load of babies on its back -- assuming that any such thought passes through the bird's mind.

There was a large flock of mixed gulls circling in a thermal over the Lido restaurant. They rapidly dispersed, and I heard the cry of a Sparrowhawk which then flew over, recognisable by its flight with alternate rapid wingbeats and gliding. Sorry about this distant picture, the best I could get.

I don't know whether Sparrowhawks take Black-Headed Gulls. Females are large enough to take pigeons, and in fact today there was a little circle of grey feathers at the bottom of Buck Hill to show that exactly this had happened earlier this morning.