Michael McCarthy: I love the sound of squeaking bats...

Nature Notebook

I don't know about you, but as November grinds towards December I am strongly missing long summer evenings, dinner outside, the glass of rosé in the balmy dusk, watching for the first star, watching for the first bat... even bat walks. Ever been on a bat walk? It's one of those things you can do now which you couldn't do when I was in short trousers, like phoning your relatives in Australia: technology has made wondrous things possible.

As the light fades, you gather with other bat enthusiasts in a group around a lake or a wood, say, and you all wear bat detectors, which are earphones in which you can hear the bats' high-pitched squeakings, the sonar signals they use for echo-locating their flying insect prey in the dark. The bat detector will identify the frequency of the squeaks, which will tell you which species is fluttering past as the shadows close in, if it's a Daubenton's bat, or a noctule, or a pipistrelle, or whatever.

It's great. It's the precise aural equivalent of binoculars for watching birds, which didn't come along until 1894 when they were invented by Carl Zeiss of Jena. Before that you just had your naked eyes, or a gun (the identification method of choice for many an early ornithologist). So thank you, technology.

I was put in mind of bats by reading that the People's Trust for Endangered Species, a small conservation charity specialising in mammals, has discovered that the best place for bats in Britain, and perhaps even in Europe, is the Isle of Wight: it has remarkably large populations of rare species such as Bechstein's bat and the barbastelle bat. (Plus its own butterfly, the Glanville fritillary, and the red squirrel, gone from most of England. Terrific stuff.)

... but not of Tinkerbell

While we're on the subject of technology, has anyone noticed what's happened to the Speaking Clock? In the past, if you dialled 123, you got an admirably grave male voice (probably a BMW-driving Conservative councillor from Guildford) who told you in solemn tones: "At the third stroke, the time sponsored by Accurist will be: eight forty-five, and fifty seconds." It was serious, solemn and wonderfully reassuring, just like the BBC Shipping Forecast. Now you get a dippy, not to say crazed, American female fairy-impersonator who shrieks: "Hi! It's Tinkerbell! At the third bell, the time will be: three o'clock, and twenty seconds!" She sounds like she's been on the happy pills and forgotten to stop. What's the world coming to? Eh?