A sunny day with a strong gusty wind. The Bearded Tits were clinging for dear life to the whipping reed heads, and even these tenacious birds were occasionally dislodged.

Like all passerine (perching) birds, they have an ingenious mechanism for holding on. The tendons that clench their toes run around the back of their tarsi -- that is, the backward-facing joints above the feet which correspond to human heels. When they perch, the tarsi bend, which applies tension to the tendons and clamps their feet around whatever they are perched on, without any muscular effort being needed. If you feed Great Tits on your hand you will know that they grip your finger with remarkable force.

It was the turn of the second-winter Great Black-Backed Gull to occupy a post opposite the Peter Pan statue, after an adult took it yesterday. Here it is with a Common Gull, a Cormorant and a Black-Headed Gull, all with their heads into the wind but still being rocked by a sudden gust.

These Great Black-Backs are not gregarious, and whenever you see any of the three on the lake, it is alone.

Some of the little Black-Headed Gulls are almost fully into their breeding plumage, with heads the colour of plain chocolate and deep crimson bills and legs.

But it will be a couple of months before they leave for their breeding grounds along the coast of mainland Europe. The Common Gull from Bremen, with its distinctive red plastic ring, is also still in the park, most recently in the Italian Garden.

Time is also passing for the young Mute Swans from last year. These ones are now largely white.

You can tell that they were hatched on the lake, as they were ringed when they were captured for their compulsory holiday during the Olympic Games. I think that these are two of the five from the reed bed that now has the Bearded Tits, since they were at one end of it. They still regard it as their territory, although their parents may have something to say about that when the next breeding season comes.

Des reports that he has seen the male Tawny Owl, who was not visible when I visited his tree; also a female Wigeon on the east side of the Vista, which I missed too despite having scanned the shore with binoculars. He also notes that the number of Red-Crested Pochard is up to ten; I only saw five of them at the Serpentine island.