The red fox, Vulpes vulpes, states the guidebook, is the largest of the true foxes and the most successful.Those words have always thrilled me, just as each glimpse of the real thing does, like this afternoon when I was toiling along the bridleway and looked up to see a tawny streak trotting across the sodden field. Caught against the horizon on a lift of land, the animal, almost half of him a tail, seemed to be swimming over the stubble like a land otter.He was on important business (foxes always are) – it’s mating time and females, in oestrus for just three weeks every winter, can conceive for only three days or so.These beautiful animals have a clear intelligence. They communicate in a sophisticated language of ear, nose and a system of yelps, whines and barks that span fiv