Join the chorus

I GUESS YOU probably missed International Dawn Chorus day on May 6 - because not everybody knew about it and because dawn at this time of year is around 4.30am, which is a tad early for most people.

Luckily (or not) I am one of those people who doesn't sleep much after dawn anyway, and while I didn't join any of the organised parties  (I failed to get one off the ground at Chartwell) I rose at dawn and stuck a music-industry standard MP4 player out of my bedroom window. The sound file is below: just click on the arrow. You may need to turn the sound up on your device.

You'll probably get the blackbird straight away, and the woodpigeon that comes in a little later. But the bird with the higher trilling call - the one that sounds like a warbler - is actually a wren. This is in quite an urban setting in a residential close on the north side of Tunbridge Wells.

So, why do birds make such a racket first thing in the morning? Well, it's not the best time for foraging - it's still a little gloomy, and there aren't many insects about - so it's a good time to mark out your territory and look for a mate. The air is still too, which means that your song carries up to 20 times further - and because it's still gloomy you are at less risk from predators

Singing takes a huge amount of energy, and the males that sing loudest find mates the quickest because they are displaying vitality and strength. Once they've found a mate, they sing less, which means that birds singing late in the season are often the disappointed and lonely males.

For experienced birders, bird song is as sure a way of identifying birds as seeing them through binoculars - unless you are listening to a marsh warbler, which is the Jon Culshaw of the bird world. An impressive mimic, this rarely seen warbler incorporates the songs of around 31 European and 45 North African species into its repertoire.

Researchers at the University of Chicago discovered that song birds dream about the songs they sing during the day. They noticed that when they were asleep, their brains showed a burst of activity in an area of the brain known as the robustus archistratalis, which is known to be involved in singing. Their hypothesis is that they are consolidating songs learned during the day.