Several of the Mute Swans around the reed rafts at the end of the Serpentine were fighting, a consequence of being crowded into a small space. It is the prospect of being fed by visitors that draws them into this corner of the lake.

The Scaup was also there. Here he is flanked by a couple of female Tufted Ducks.

The pair of pale Red-Crested Pochards seen on the Round Pond yesterday had moved down to Peter Pan, where they were mingling with a normal-coloured pair.

Here are some more Red-Crested Pochards near the Serpentine island, two drakes chasing a female.

These birds fly around quite a lot, and presumably the reason why their numbers on the lake fluctuate so much is that they are flying to and from Regent's Park, where there is a permanent resident population.

Update: Africa Gómez, author of the consistently interesting blog The Rattling Crow, suggests in yesterday's comments that the reason for the paleness and smallness of the Red-Crested Pochards may be inbreeding. The population in Britain is founded on a few park escapes and has only recently grown to reasonable numbers.

The Grey Herons' nests on the Serpentine island have been unused for days. Here a female Mallard examines one. Mallards do nest in trees if they can find place to land and perch, and she might be thinking seriously about this place.

Some second-year Herring Gulls were playing their usual game of knocking each other off the posts around the Serpentine island.

I also saw a Herring Gull with an orange plastic leg ring, P2MT. I have reported this to the main organisation for ringing, Euring, and hope to find where the bird comes from.

Near the Rima relief a Blue Tit was hanging upside down from a twig, searching busily for grubs among the growing leaves.

The male Little Owl showed himself briefly, as usual in the chestnut tree next to last year's nest tree.

The male Cetti's Warbler was singing loudly on the west side of the Long Water. I saw him a couple of times and tried to photograph him, but only succeeded in getting a bad shot of a female Blackcap. There are a lot of little brown birds in this place.