The Tawny Owls are internationally famous. Today as I was going round the Serpentine a man from Boston, seeing the telltale roof prism binoculars round my neck, came up and asked me where they were. There has also been a visitor from Norway looking for them. The owl family and their father were in the four horse chestnut trees between the nest tree and the path, the owlets moving around restlessly and their father asleep in the third tree from the north. Their mother was in the nest tree, very hard to see.

Many Green Woodpeckers were calling loudly in both parks, and the nest beside the path was attended. Another bird was in the Leaf Yard very close to the tree where the Great Spotted Woodpeckers are nesting.

There were three male Mandarins and  one female on the Long Water. They come and go freely between here and the Regent's Canal, which is where they have the best breeding success because there are trees close to the water and not many large gulls. The pair of Gadwall is still here; they too come and go between here and Buckingham Palace gardens, where they breed. They have not tried breeding on our lakes and, seeing what happens to Mallard ducklings here, I don't blame them.

Two Little Grebes were calling loudly to each other.

The old tern raft, now replaced by a larger one, is still drifting around the Long Water and today had fetched up near the bridge. The idea was to attract the Common Terns whose main area seems to be the Grand Union Canal, but no birds have ever tried to breed on the raft. One I saw a pair flying around it, but they didn't even bother to land. When they visit the park they usually sit on moored boats in the middle of the Serpentine.

I went to the French Embassy to see if any House Martins had arrived: none yet, but this is a place to watch at this time. After two bad years, the first caused by rebuilding work, the second by a drought that denied them mud for their nests, it will be a while before their numbers build up again. In contrast, the colony on Rossmore House near Regent's Park did well in both the last two years.

One of the Grey Herons' nests on the Serpentine Island was busy, with two chicks being fed. (Difficult to think of these big gawky creatures as a chick.) Another nest had an adult in it.

In the Flower Walk, I heard an odd repeated call, like a very short blast on a referee's whistle. It turned  out to be a Nuthatch. I have never heard one calling like this before.