Why do birds sing?

Although I do enjoy the occasional dip into New Scientist, the great thing about having no attachment to empiricism myself is that I can happily entertain all kinds of crazy notions. For over twenty years now my partner and I have practised chakra chanting - singing tones into each of the seven energy points, or chakras, of the body (according to some eastern belief systems). We learned it from a charming old hippy who subsequently moved to a remote part of Wales. Apparently it is based on a north Indian Buddhist tradition, although we have modified it to suit ourselves, but I couldn't say for certain and for once I actually like knowing nothing for certain about its origins. I am happy to be free of any of the restrictions that come with dogma.

It makes us feel good but I doubt I could prove that. I have some vague idea that it's to do with vibrations and the fact that humans are largely made of water. We don't do it to attract mates or to warn others off our territory, although I know people who sing for at least the first of these reasons.

This morning I heard the wood pigeon in the picture calling from the roof of my studio. It put its whole body into it - a large sound for such a small creature - and followed up with a thorough preening session. I have reason to believe it was courting and, when another male pigeon arrived they shared the space peaceably for a while before the singer flew away. So, obviously not defending its territory then.

Could it be that some birds, in addition to whatever other reasons they may have, sing because it makes them feel good? Because it vibrates their molecules in a health-giving manner?

While photographing the pigeon I caught a rare glimpse of an urban woodpecker and that was enough to make me feel good.