The young Great Black-Backed Gull was back on the Serpentine. It is a second-winter bird, about 18 months old, and is still looking very young and speckled, with only a few feathers of its dark adult plumage beginning to grow on its back. It will still be partly speckled next year as it goes through its four-year adolescence.

This seems to be one of only two Great Black-Backs that visit the park; the other one is a full adult. There are occasional reports of what may be them appearing elsewhere in London; for example there was one at Wanstead Flats yesterday. But their movements through London are mysterious and there is no clearly identifiable individual, for example with a ring. Indeed I wouldn't blame anyone for not wanting to put a ring on this ferocious great creature.

Some of the Great Crested Grebes are already beginning to grow their breeding plumage. This one was fishing in the shallow water just offshore from Peter Pan.

The Cormorants had taken a few minutes off from their fishing in the wire baskets next to the bridge. This one, resting on an adjacent post, is a juvenile bird, as can be seen from its whitish front.

A Grey Heron had taken advantage of the break to prospect one of the baskets.

I waited for several minutes to see if it would catch anything, but it didn't. It would have been fully visible to the fish in the basket, so maybe its fishing technique of patient waiting is not effective here. Cormorants and Great Crested Grebes rush in and grab fish, and seem to do better.

A brisk wind was whipping round the trunk of the Tawny Owls' rest tree, ruffling the feathers of the male owl.