As the adult Great Crested Grebes fade into their winter plumage, and the young ones grow into adulthood, they are becoming increasingly similar in appearance. Soon the only visible difference will be that the adults have a faint vertical dark stripe on their cheek, a vestige of their colourful ruff, and the young ones have a faint horizontal stripe, the last remnant of their juvenile stripes.

Gulls of all sizes were bearing off food scraps dropped by the crowds at the funfair, and being chased by others to harass them into dropping their prize. The chase is conducted from below, so that if the quarry drops the food a pursuer can snatch it in a split second.

Black-Headed Gulls were also crowding a group of Tufted Ducks on one of the Italian Garden ponds, for no clear reason as the ducks were not bringing up anything large enough to interest them. On the left a duck is diving in the peculiar way of small diving ducks, in which it jumps up in an arched posture to give it impetus to submerge more deeply.

They need to do this because they are quite buoyant. Grebes can make themselves less buoyant by clenching down their feathers, and don't need to jump unless they are planning to dive very deeply.

The pigeon-eating Lesser Black-Backed Gull had been forced off its usual pitch at the Dell restaurant by the mass of humans, swans and geese, and was hunting at the opposite corner of the Serpentine near the bridge. Here it is looking bloody and ominous, but it is only doing what comes naturally to a gull.

The Tawny Owls were in the same place as yesterday, and this is practically the same picture as yesterday's. But how spoilt we are, being able to stroll into the park and reliably see a pair of these beautiful birds.

The little flock of Greylag Geese feeding on Buck Hill had stationed themselves in front of a pretty autumn tree.