'A Glastonbury for twitchers': 20,000 enthusiasts flock to the world's biggest birdwatching event

They came from London and they came from Scotland, they came from Norfolk and they came from Cornwall, and oh, much farther away than that.

There was a guy from Tobago offering rum punch and a long-bearded Pole who had driven his family across Europe, and there was the Israeli guy and the Palestinian guy, and the Israeli had given the Palestinian a lift.

There were people from Burma, Goa in India, The Gambia, Italy, France and Spain and just about all over South America. There were old and young, atheists and believers, blacks and whites, gays and straights, the able-bodied and the disabled, and every one a birdwatcher.

There isn't anything quite like the British Birdwatching Fair, which opened yesterday for the 17th successive year on the banks of Rutland Water, the giant reservoir-cum-nature reserve in the east Midlands.

Now known simply as Birdfair, it is the biggest ornithological event in the world, bringing together more than 300 exhibitors of every product you can think of to do with wild birds, from more than 70 countries, and bringing close on 20,000 enthusiasts to see them, over three days.

It was started from scratch in 1989, after a pub conversation, by the two men who still run it: Tim Appleton of the Leicestershire and Rutland Wildlife Trust and Martin Davies, of the Royal Society for the Protection of Birds.

They began with a marquee in a field and 300 visitors: now they have something that has become, in the words of Stephen Moss, the writer and producer of BBC's Springwatch nature series, "a cross between the Chelsea Flower Show and Glastonbury". For growing numbers of Britain's vast army of birdwatchers it is an unmissable event.

They come to feast their eyes and blow their budgets on a cornucopia of birding goodies: thousands of books, guides, paintings, sculptures and photographs; scores of bird holidays, trips and tours; dozens of bird tables, bird feeders, bird foods and bird hides; racks and ranges of countrywear such as stout boots and anoraks and, most enticingly of all, optics.

Visitors were also treated to the mostmouthwatering display of top-of- the-range telescopes and binoculars from Swarovski, Leica and Zeiss, the three kings of the birding optics market, and Nikon, the young prince coming up fast on the outside.

The huge optics marquee at the Birdfair looks out directly on to Rutland Water with its celebrated concentration of wildfowl, thus allowing scopes and bins to be tested in natural conditions and, yesterday, crowds were queuing up to do so, gazing hungrily on such glistening objects of desire as Swarovski's famous ATS 80 HD telescope, a snip at £1,382 (although you'll get it cheaper).

They were buying them, too, buying them freely. The value of the birding optics market runs into many millions of pounds and the Birdfair is a huge marketplace where enormous volumes of business are transacted.

But that's not its real point. The key aspect of the event is social. " It's a gathering of the tribe," said Mark Cocker, one of Britain's leading writers on birds and birdwatching.

Mr Cocker has written convincingly on birders as a distinct tribal grouping, with their own language, customs and codes of behaviour, and observing the crowds yesterday he said: "It's like the San bushmen of the Kalahari, who live in small family groups but come together every year for a gathering of the whole.

"There is this moment of social discourse, when old friendships are renewed, old debts are repaid, prospective partners can meet one another and business is transacted."

The international flavour of the event is remarkable. Yesterday you could book a tour to see the elusive great snipe with Marek Borkowski, who runs the Biebrza Marsh wildlife reserve in north-east Poland, or you could share a glass of rum punch with Duane Kenny, general manager of the Blue Waters Inn in Tobago - "Birding is best with binoculars and a bottle of rum 'cos the birds just seem to multiply" - while musing on a trip to the hot island to see the sabre-winged hummingbird.

You could even chat to Imad Atrash, executive director of the Palestine Wildlife Society, who is trying to save Wadi Gaza, the wildlife-rich wetland of the Gaza Strip and who was given a lift from London to Rutland Water by Dan Alon, director of the Society for the Protection of Nature in Israel. "We get on fine," said Mr Atrash.

Last year Birdfair raised £164,000 for projects in Peru; this year they hope to raise even more to save Gurney's pitta, a beautiful but critically species of endangered thrush that lives in south-east Asia

A bird in the hand-held ...

Not only a bird in the hand, but now a bird in the ear: it's the latest piece of kit in cutting-edge ornithology.

The Collins Bird eGuide is a mobile version of the company's best-selling guidebook to European birds, and works on a PDA, or palmtop PC.

All you do is insert the memory card. Then hold it in the palm of your hand: there's your bird in all its different coloured plumages, the notes on its appearance and habits, and the map of its distribution, but then - wait for it - you simultaneously hear its call.

There are 450 individual calls in the programme, which had some of the assembled birders gasping in admiration yesterday.

The e-guide was commissioned and is being distributed by WildSounds of Salthouse in Norfolk, who charge £79.95 for the card only, or £319 together with a palmtop PC. It is likely to be a must-have on many a birder's Christmas list.