Most of the Great Crested Grebes have left the lake, as they do when frosty weather arrives to avoid being trapped by ice. Since they need a 50-yard run on open water to take off, ice is a serious danger to them. I think they fly up the Thames, as there are quite a lot of grebes upstream from Chiswick.

However, this pair on the Long Water seem to be newly arrived. Perhaps they are on their way to the river from some smaller and more ice-prone pond.

They are already in full breeding plumage, and both have unusually dark faces. I don't think I've seen them before, as the dark-faced grebe who was on the lake in previous years had a mate with a normal amount of white.

There was a pair of Pied Wagtails hunting insects in the grooves of the non-slip mat on the jetty of the Lido swimming area.

Then they flew to the roof of the Lido restaurant and started investigating the crevices between the slates. Any small gap may harbour a bug. I have seen one trying to climb a tree trunk like a Treecreeper looking for insects in the cracks in the bark. But wagtails' feet are for running on the flat, and it didn't get far before it lost its hold.

A Long-Tailed tit paused for a moment on an oak tree near Peter Pan.

The tree has small leaf buds on it, which must have developed prematurely in response to the mild autumn weather. Trees seem to be able to recover from these mistakes without serious harm.

The Ring-Necked Parakeets are becoming rather troublesome. If you feed one, you get them all over you.

The male Tawny Owl was out early in his usual place on the nest tree.

And here is a picture of the tree, taken from the path that runs between the Physical Energy statue and the Speke obelisk.

If you stand on the path at the midpoint between these two monuments and look west, towards Kensington Palace, you will see this tall, left leaning horse chestnut tree -- note its distinctive broken trunk. You can just see the owl in this picture at the tip of the arrow. The beech tree in which the female owl sometimes perches is just beyond it and a little to the left, still with some brown leaves.

There are a dozen mossy stones on the south edge of the Serpentine between the Lido and the end of the lake. They have been picked out of the lake by the young Herring Gulls, who like to play with them.

This Black-Headed Gull at the Round Pond had a different toy, an individual Wetabix wrapper which was fun to chase as it blew around.