Nearby, three Mute Swans were displaying at each other. Eventually one drops out of these contests to leave a couple (though the Black Swan seems quite happy to have two companions).
The dominant swans on the Long Water were on their island, picking up leaves as if about to build a nest. (Is the Black Swan's behaviour symbolic of nest building? He does it when he's on his own.)
None of the birds seems to have been put off springtime behaviour by the cold snap. Nevertheless, it is cold, and there were patches of ice on the lake. On one of them, a Black-Headed Gull was playing with a stick.
A Great Tit was inspecting a possible nest hole in an old chestnut tree in the leaf yard.
A Coal Tit was singing at the top of the next tree. Here is one of the three Coal Tits in the leaf yard coming down to be fed.
Two Nuthatches were also attracted by the prospect of food.
There was also a pair of Treecreepers, though they don't come to be fed. Tom Bell took this fine picture of one of them.
The Robin who owns the olive tree next to the Lido restaurant was singing loudly to defend it.
There was a single Goldfinch in a tree at the foot of Buck Hill. It wouldn't come out of the shade, so this dark picture will have to do.
On the dead willow tree by the Italian Garden, a Carrion Crow and a Grey Heron were having a face-off.
There is good news: yesterday Des McKenzie was in the park early in the morning and heard the Tawny Owls calling all along the path that runs from Lancaster Gate tube station to Queen's Gate via the statue of Physical Energy. There were also calls from Buck Hill; the owls were hunting and covering a wide area. Needless to say I couldn't see anything when I walked around today. But we know they are there, and it's only a matter of time before someone finds them. These owls sometimes call in the daytime, and that would be a much better way of finding where they have established themselves.