The pair of Great Crested Grebes at the Serpentine island stole a Coot's nest -- the Coot left when it heard them arriving -- and mated on it, exchanging many affectionate head shakes. This is quite a slow business by the hasty standards of birds, and this video has been excerpted from an original 4 minutes long. Although Great Crested Grebes can always chase Coots off a  nest, the Coots will get it back in the end, with their typical dogged persistence.

Moorhens, like Coots, are much less ceremonious about mating. Here a male chases a female, who isn't in the mood.

Another Moorhen was stealing twigs from a temporarily unoccupied Coots' nest near the bridge.

Johanna had borrowed my video camera and was filming some Mute Swans courting, with a pair of Greylags washing in the background. It didn't look as if anything was going to happen, but suddenly the Greylags started mating, and luckily she caught the moment.

This nesting swan near the bridge was closely attended by a pair of Coots. Johanna mentioned that in California hummingbirds often nest near the nests of Red-Tailed Hawks. The tiny birds are too small to interest the hawk as food, and they get the protection of being near a dangerous predator.

A young swan was enjoying itself in the spray of the water inlet of the Round Pond. It seems odd to see one of these moody birds having fun.

One of the female Pochard--Tufted Duck hybrids was cruising around at Peter Pan. They have interesting marmalade-coloured eyes, intermediate between the yellow of a Tufted Duck and the brown of a female Pochard.

The mild grunting noise of an annoyed Mandarin drake is as near as these quiet birds get to quacking. They also make a gentle peep-peep-peep noise as a social call.

Grey Herons seem endlessly patient as they wait for fish, but this one on a post under the bridge had a moment of boredom.

Most of the Black-Headed Gulls have left for their breeding grounds, which may be as far away as Finland or as near as the Pitsea landfill site just to the east of London. There was just one on the Serpentine, and no Common Gulls. But there still were several of both species at the Round Pond, here mixing with the local Herring Gulls which don't migrate.

On the edge of the Round Pond a Carrion Crow played with a round seed. Its wings are faded, probably as result of a bad diet of junk food from the restaurants in Queensway. This happens particularly with young crows, which need good nutrition as they grow.

Both Peregrines were on the tower of the Household Cavalry barracks, but one left before I could get close.

The female Little Owl near the Henry Moore sculpture was in her usual place in the lime tree.

The overnight rain left the soil soggy -- good conditions for Blackbirds to get worms.

One of the regular Robins beside the Long Water came out to be fed.

Goldfinches came down to the feeder in the Rose Garden.

Work on the shelter at the bottom of Buck Hill is finished at last, just in time for Starlings to start nesting under the eaves.

A pair of Long-Tailed Tits gathered lichen to make one of their complex spherical nests. They are built of spider webs filled in with lichen and moss, and lined with literally thousands of little feathers, all of which they diligently collect.