For the last couple of days I've been transfixed by a local songbird whose range and repertoire is outstanding. Like a great jazz soloist, this improviser did a good three minutes without breaking stride — reciting a range of sounds that covered an impressive spectrum of tweets, trills, and chirps. "Must be a mocking bird," I thought. Today after another virtuoso performance, the maestro appeared briefly, swooping from one tree to another in triumph (I assumed). It was like the Charlie Parker of birds and maybe this was its version of a bow. But then it seemed there was another mocking bird in the vicinity. Was it a courting ritual? A competition? (Like a rap battle.) 'How long had it taken to learn all those sounds?' I wondered...Months? Years? Centuries, or more likely millennia. I was hearing the culmination of eras of evolution and unlike the subtler results of the process, I could sit in my garden and take it in - two quite different species with at least a roughly equivalent idea of beauty.