A pair of Great Crested Grebes are building a nest on the Long Water, in the willow tree next to the bridge. They are easy to see but very hard to photograph, as the hanging willow twigs make a curtain in front of them.

Every few minutes they stop working and have a display session to encourage each other. Here they are in the shadows underneath the bridge.

The larger one of the Grey Herons' nests on the Serpentine island, apparently deserted four days ago, is now occupied. You can just see the sitting bird's head over the top of this huge construction of twigs. At times it is completely invisible, and it is possible that it has been on the nest all this time.

The Scaup, although a genuinely wild bird, has become quite tame after six weeks in the park, and comes to be fed. Here it is at the landing stage in front of the Diana fountain.

I didn't hear the Cetti's Warbler today. When I played a bit of Cetti song in front of its usual place, there was a reply, but it was a Song Thrush doing a realistic imitation. The thrush was invisible in the holly tree, but it was having a song duel with its neighbour, pictured here.

This Black-Headed Gull is quite an old bird, as you can see from the deep red colour of its feet. It has a ring, EP24143, which was put on by Roy Sanderson in December 2002. It regularly spends the winter in the park and has been seen several times.

Black-Headed Gulls can live to over 30.

The female Little Owl was in the next chestnut tree up the hill from her nest tree, looking out of a large diagonal hole in the broken trunk.

The male Tawny Owl spent the morning inside, but emerged from his hole at 4.15.