The second pair of Great Crested Grebes who nested on the Serpentine island and lost their brood are nesting again. It is much too late by normal standards, but there is plenty to eat and they might get away with it if the autumn and early winter are mild. All the nesting behaviour of the water birds has gone awry over this unseasonable summer. The nest is inside the row of baskets at the west end of the island, and visible from the shore with binoculars.

The Great Crested Grebe family from the bridge had ventured as far as the Lido. The four young ones are large enough to be out of danger from large gulls, and were rushing around briskly calling for food. Their mother seemed to be getting bored with their constant demands.

Also very late, a Mallard on the Round Pond stands guard over her seven ducklings. While I was there she managed to keep some Greylag Geese, two Mute Swans, a flock of Starlings and a Carrion Crow at bay merely by fixing them with her motherly eye.

There has been a bad outbreak of toxic blue-green algae in the Dell. They are also in the little pool at the top of the waterfall, but the main lake is clear, so evidently the growth started in the filter beds at the lake outflow. There had been some ordinary green algae for a few days. When these die, the blue-green algae grow on the debris. They smell foul, and I think the birds avoid them. The Moorhens in the Dell had got out of the water, and one of the Grey Wagtails was looking for insects in the middle of the lawn, far from its usual waterside hunting ground.

There are still some House Martins flying around the Kuwaiti embassy.