When Grey Herons get too close to each other, there's a quarrel. Oddly, the young heron with a plain grey head seems to be dominant here, when you'd have expected it to be at the bottom of the pecking order.

There were also some in the Rose Garden, looking out of place against the herbaceous borders. But there are plenty of rats here for them.

A heron caught a fish in the little pool at the top of the Dell waterfall. This pool is not connected with the Serpentine and is artificially filled by a pump in the stream at the foot of the waterfall, so I had supposed that there were no fish in it. I was wrong.

This pair of Lesser Black-Backed Gulls have been at the north end of the Long Water for a while, often displaying to each other, and it looks as if they're planning to nest. They will probably do this on a flat roof somewhere just outside the park.

The dominant pair of Mute Swans on the Long Water were back together after a week of separation. Maybe these extremely aggressive birds had had a marital dispute.

The male got back to his usual routine of attacking all the other swans.

Mark Williams reported from St James's Park that the four Egyptian goslings are still in good order. Here are two of them.

There is also another brood of four. They have a better chance of survival in St James's Park than here, as there are fewer big gulls.

The Coot which has been trying for months to start a nest on the dead willow tree near the Italian Garden has finally succeeded in getting a few twigs to stay in place. Sheer dogged persistence has paid off.

Another Coot on the edge of the Serpentine laid the first twig in a nest that doesn't have the slightest hope of success.

The female Little Owl near the Henry Moore sculpture was out on a branch. It was a chilly day but at least the wind had dropped, and this pair of owls seem hardier than the others.

A Jay ate a peanut.

A Robin found a small white grub under a tree.

Another bathed in a puddle.

A Goldcrest sang while flitting around in a tree next to the bridge, at the corner by the Magazine.

This is a Treecreeper nest in a horse chestnut tree bear the Serpentine Gallery. The birds have reduced the size of a natural hole by blocking up the bottom with little bits of wood.

Neil pointed out two young trees beside the Serpentine that I hadn't known about. They are cork oaks.

When the tree matures the trunk is covered with thick spongy bark which can be stripped off without killing the tree and used to make corks. Here is a close-up of the bark, still quite thin on the young tree.