Prolonged rain followed by frost has left much of the park a half-frozen swamp. Here a pair of Mallard enjoy a flooded path behind the Albert Memorial.

Yesterday I showed a picture of a young Lesser Black-Backed Gull playing with a stick on the edge of the Serpentine. Andy Sunters commented, 'As they get a bit older they actually fly up with their "toys" and drop them and chase them down, grabbing them again.' And today the gull, a few yards offshore from where it was yesterday, had taken the next step in the game, dropping its bit of stick into the water and diving to grab it.

It had not yet mastered the trick of catching it in the air, which obviously needs practice.

One of the Great Crested Grebes under the willow tree near the bridge was maintaining their nest, bringing bits of twig and dropping them rather haphazardly on the messy tangle they call home.

The nest had sunk noticeably lower than it was yesterday, and needed building up. It's less work for the birds when they nest in reeds, where the nest doesn't sink daily. The pair near the reed bed at the east end of the Serpentine, however, have put nesting on hold until the weather improves.

The east end of the Serpentine is also where large numbers of low-ranking Mute Swans from the Round Pond congregate to choose mates and try their luck at getting a nest site. Here a pair -- the right-hand two -- are interrupted in their courtship by another male, who is trying to take over the female.

Surprisingly with these violent birds, it didn't come to a fight. The pair simply ignored the intruder, and after a couple of minutes he went away, leaving them to their courtship display.