For reasons that will be well understood, I preferred not to study the newspapers straightaway this morning. Instead, I went with the dog out to Berthem for an early walk on a beautiful day. I have always been fascinated by the way agricultural landscapes are constantly changing. A sweet corn crop is harvested and suddenly a fresh vista opens up. Or (in the picture) a set of different plantations are suddenly ploughed together into a massive field, creating a single horizon. On the way we were treated to a spectacular flying display by a hobby, being mobbed by a crow. Why do carrion mob birds of prey? It must be deeply ingrained in their genes but I always wonder why. In this case the lumbering crow wasted huge amounts of energy trying to keep up with its swift and agile target. What is the evolutionary gain in such behaviour?