One young Grey Heron has emerged from the nest on the Serpentine island -- seen here exploring the strange new world downstairs.

The other one was still in the nest when I went past. Nearby, some male Common Pochards were menacing one another with a harsh 'brrk, brrk' quack. I wonder whether they are actually getting around to breeding. I have not seen this before, although the more exotic Red Crested Pochards have been breeding here for several years.

Three male Mandarins were wandering around the Long Water together, at a loose end because their mates are nesting in tree holes somewhere nearby.

At least 200 Swifts were whizzing around over the Serpentine, with a few Swallows and House Martins mixed in. I went to the French embassy to check for signs of House Martins nesting but saw nothing, apart from a solitary Cormorant headed in the direction of the Buckingham Palace lake.

At the Tawny Owls' nest site, one owlet was partly visible in one of the trees at the front -- just a pair of eyes peering over the top of a leaf. Now that they have almost completely adult faces, it can be said that this youngster takes after its mother, with the same high-arched eyebrows -- she is the one on the left in this photograph taken late last year.

Stephen reports seeing a pair of Reed Warblers flying over the Long Water near the bridge. A bit later in the year, their harsh clattering song is often heard in this reeds around the lake.