The Little Grebe, previously seen only at a distance across the lake, came quite close when it briskly crossed the gap at the Peter Pan statue. It is already in winter plumage.

Little Grebes hunt for fish and small invertebrates along the banks of the lake, so they are constantly circulating. Later I saw it flying across the Vista, perhaps taking a short cut past an area which was of no interest to it. As usual with Little Grebes, it made no attempt to come down in a conventional way and plunged from the air straight under water, surfacing some distance away under the bankside bushes.

There were other visible changes to plumage as the autumn moult gets under way. One of the Mallard drakes is now already in his full finery, his green head looking wonderfully iridescent even on a dull day because the feathers are brand new. This is an interference colour caused by tiny ridges on the barbules of the feathers, so it becomes less intense as the feathers get worn down by time and preening.

And one of this year's Black-Headed Gull was showing signs of abandoning its tweedy juvenile feathers and growing an adult's grey and white plumage.

Unlike the large gulls, which take four years to achieve full adult plumage, they do it in one year, and only their marmalade-coloured legs show that they are young; later these will turn a deep beetroot red.

The Great Crested Grebe family at the east end of the lake were paddling causually around the netting where their nest was, not doing anything remarkable but it was good to see that they are still all there and in good order.

The area around the Henry Moore statue is looking very odd. The plan was to make a wildflower meadow, something that the park staff have done very well before, producing attractive stands of cornflowers, poppies and other British native plants. However, this area was attended to by contractors who don't seem to have fulfilled their brief. After an early strong growth of thistles some very strange and certaintly non-native plants have come up, including many tobacco plants with flowers of various colours -- not unattractive but definitely North American. Perhaps the strangest arrival is this Squirting Cucumber, Ecballium elaterium.

It is a native of the Mediterranean coast. The seed pods inflate with liquid as they develop and eventually explode, hurling the seeds a considerable distance.

Update: Mario points out that this last identification was wrong. The plant is a Thorn Apple (Datura stramonium) and is poisonous.