Listen. It is half-past three in the morning, and if you are not sound asleep you jolly well should be. But something is happening outside your window. Something is stirring. It begins with a peep, a whistle and a trill, then starts to build in complexity and volume. By 4am, the air is ringing like a cathedral belfry as a thousand male birds compete for attention. Dawn is in full throat.
Imagine now, as you close your eyes in an effort to fend off wakefulness, how at this very moment that wall of sound will be making its great daily progress around the planet, shadowing the racing grey line which is the boundary between darkness and light. For the dawn chorus is a moving feast, a global phenomenon, a concert that is forever opening at the next venue.
Of course you know that is a fact, just as you know that the earth is round. But this Sunday, for the first time, anybody with a radio will be able to hear this mobile, worldwide concert for themselves. For BBC Radio 4 is celebrating International Dawn Chorus Day with four hours of programmes devoted to animal sounds, birdsong in particular.
Listeners will be able to tune in as dawn breaks around the planet, from 5.48am with the great reed warbler in Sweden to 11.31pm with a chorus of marsh frogs in Russia (it's not only birds that awake with a song in their heart). The day's full-length programmes begin at 6.35am with Tyneside Dawn, in which leading wildlife sound recordist Chris Watson presents a portrait of daybreak in his home town of Newcastle. With many rural bird reserves closed this spring because of foot and mouth disease, the sound of robins and blackbirds tuning up against a background of throbbing nightclub music and clanking railway wagons is a cheering reminder that nature is alive and singing in cities.
It's a point that is echoed by Chris Baines, who was instrumental in setting up the first International Dawn Chorus Day in 1983, and who presents one of the day's highlights, a programme called Why Do Birds Sing?. Baines travelled with Watson to the Cornell Laboratory of Ornithology in New York State to hear the sounds of the 220-acre Sapsucker Woods wildlife sanctuary, and to talk to researchers about their extraordinary findings in the field of animal communication. There he learned how elephants use low-frequency soundwaves to communicate over 200 miles, how antelopes use their hearing to predict floods and how female songbirds select a mate according to how skilfully he executes those fancy trills at daybreak.
But, he says: "I couldn't wait to get back to my little garden in Wolverhampton and to hear it differently. The quality of the dawn chorus in Britain is particularly good because we have a mixture, in our gardens particularly, of open-space and woodland specie. But it's also a very good indicator of environmental quality and of the roll-over there has been between rural and urban Britain.
"If I really want to be depressed, I'll go and try to find a good dawn chorus in farming Shropshire. But here in the middle of Wolverhampton it's absolutely deafening."
Even Bill Oddie, who introduces each of the 40-second round-the-world drop-ins throughout the day, returns to London to present his own programme, Up With The Bark. His favourite patch for bird listening is Hampstead Heath, and it's there you'll find him at 5.40pm, muttering to himself as he avoids the ubiquitous dog-walkers. ("You never, ever, get out before the dog-walkers," he says. "There are people, I swear, who walk their dogs there all night.") But it's to the wilds of Scotland that Chris Watson turns when he sets off, microphones in hand, to track down the black grouse, a bird whose mating call is said to be one of the noisiest and most exciting early morning sounds to be heard in Britain.
Sound Advice, at 2.45pm, is a fascinating insight into the techniques used by the wildlife sound recordist. And it's an insight that Watson, whose interest began when his parents bought him a tape recorder at 11, enjoys sharing with children.
"It started when friends who were teachers invited me into the classroom to present sounds from Africa or South America, and to describe what it's like living in a rain forest or camping on a glacier. Sound can be a very powerful experience, so I try to get the room fairly dark and bring along large, high-quality speakers so that they can really hear what it's like.
"In the rainforest, it can be very difficult to see anything, and people often navigate by sound. It's interesting to communicate that idea to children, and I find that seven- or eight-year-olds are very open to listening without the need for visual images."
That's a skill that Radio 4 listeners have perfected over the years, of course. And with regular programmes such as Poetry Please and The Archers weighing in with dawn chorus themes, few of them will be going to bed on Sunday night without a clear picture in their heads of what will be taking place outside in just a few hours.
UP WITH THE BIRDS
Radio 4, May 6
6.35-7.00am Tyneside Dawn
1.30-2.00pm Why Do Animals Sing?
2.45-3.00pm Sound Advice
2.45-3.00pm Poetry Please
5.40-6.00pm Up With The Bark
7.02-7.15pm The Archers
8.02-8.30pm Music To Our Ears
12.15-12.45am Global Sunrise
The World Awakes
40-second items introduced by Bill Oddie
5.48am Great reed warbler, Sweden
7.10am Great northern diver, Greenland
8.44am Musician wren, Brazil
9.59am Giant otters, Venezuela
12.33pm Brown thrasher, US
4.31pm Trumpeter swans, Alaska
7.02pm Tui birds, New Zealand
9.02pm Birds of paradise, Papua New Guinea
11.31pm Marsh frog chorus, Russia