Last Sunday I stood on an old bridge, and watched a little river meander through its water meadow. Thick colonies of willowherb turned the banks purple, and the slow current waved with flag iris and yellow waterlily. Banded demoiselle damselflies flew languidly over the waterweed, their metallic blue bodies glistening. A pike nosed upstream, disappearing into the shadows of the bridge’s stone span. A grey wagtail flew out from the bridge and headed downstream.