The youngest Great Crested Grebe on the lake, from the nest at the east end of the Serpentine, was stretching a pair of well developed wings, as if anxious to be airborne. But it is only a little over two months old, and probably can't manage it yet.

The Black-Headed Gull whose ring I photographed yesterday is at least 14 years old, and its odyssey has been well recorded. Roy Sanderson told me that ET34518 was ringed in St James's Park on 13 January 1999.  It was seen there again in February 2003 and October 2003. It was next seen in Kensington Gardens on 6 December 2005. On 7 March 2006 it was seen in the Netherlands at Schellingwouderbreek, which is a wetland park on the outskirts of Amsterdam.  It was back in St James's Park on 4 October 2006. Then it popped up in Regent's Park in January 2008, and Hyde Park on 24 November 2009, 10 November 2010 and 23 November 2011. This is unusual behaviour for London gulls as almost invariably they stay put in one place until they migrate in February or March.

The six young Egyptian Geese on the Round Pond were alive and well, and being looked after solicitously by their parents, who saw a running dog from 100 yards away and chivvied them efficiently into the water.

A Pied Wagtail was sprinting round the pond, hunting for insects. Its black and white plumage is a most effective camouflage at the water's edge.

The yew tree on the path north of the Peter Pan statue still has a fair quantity of berries on it, and when I pass it I always look out for a Song Thrush or Blackbird deeding in it. Today I saw something moving in the tree and took a closer look. It was a rat, happily eating berries.

They are intrepid climbers and I have sometimes seen them twenty feet up in a tree. If they should happen to fall out, they are small enough not to be injured when they hit the ground.