Our old friend the Black Headed-Gull with ring number EY09813 is back in Kensington Gardens, in the same place as before, on a post at the Vista. It remembered me, and came over to be given a piece of biscuit.

This bird was repeatedly seen here from 24 November last year until at least 22 March,by which time it had developed the black head of its breeding plumage and was off to an unknown place. It was ringed as an adult in Kensington Gardens in January 2011. Gulls, in common with many migratory birds, tend to return to exactly the same spot.

On the Serpentine, a young Lesser Black-Backed Gull was displaying its impressive 4 ft wingspan.

The female Little Owl retreated behind a branch when I approached her chestnut tree and stared at me suspiciously over the top for half a minute before she went into her hole.

When I came back a couple of hours later she had just gone in again, after being annoyed by the rattling of a pair of Mistle Thrushes perched on the dead branches at the top of this ancient tree.

As soon as she disappeared, the thrushes abandoned the tree and went off to scold first a couple of Carrion Crows, then a Magpie which they chased completely away. They are aggressive birds, but their aggression is sensibly directed towards predators.

The Great Crested Grebes at the Serpentine bridge were keeping their chicks on one side of the bridge and catching fish for them on the other side. This confused the rapacious Black-Headed Gulls quite effectively and there were not too many attempts to grab the food. Here one of the chicks has folded up one leg in the usual resting position. In an adult this would hide the leg under its wing, but these quite young chicks have undeveloped wings, so the leg remains visible.

It is old enough to have grown feathers almost completely over the patch of bare red skin on top of its head, whose colour stimulates adults to feed it. Not that the adults need much stimulation, as they are the most devoted parents and feed their young for over three months.