Wonderful walk through Richmond Park early this afternoon. Sunny but cold. Interesting moment when we came up towards the Ballet School and saw a tumbling ball of birds, involving claw-to-claw fighting between several parakeets and a jackdaw. There were parakeets sitting on various trees nearby, watched by a scattering of jackdaws. A brilliant green parakeet head emerged from a hole in the tree shown here, giving us the sense that the two species were fighting for territory.