The event from Friday to Sunday, August 15 to 17, is one of the biggest events in the county calendar.

Hotels will be packed out and the reservoir shores lined with celebrities, birdwatchers and Rutland residents all keen to get a slice of the ornithological action.

Joint organiser Tim Appleton said: "It is remarkable to reflect that, as we enjoy ourselves again at this year's Birdfair, standing around in tents in a field in Rutland, there are now forests, wetlands, grasslands and albatrosses that have a more secure future thanks to the collective efforts of Birdfair supporters.

"Working together, we are making a difference."

Each year the event raises thousands of pounds for wildlife projects around the globe and this year the running total is set to top the £2million mark.

This year's money will go to help critically endangered birds on the brink of extinction.

Mr Appleton said: "Because this is such an important initiative the British Birdwatching Fair has agreed to support it for three years, in 2007, 2008 and 2009.

The money raised will be used to support an initiative with the aim of seeing many birds come off the Critically Endangered list and have a more secure future."

Species set to benefit include Sociable Lapwing Vanellus gregarius, Spoon-billed Sandpiper Eurynorhynchus pygmeus, Dwarf Olive Ibis Bostrychia bocagei, Azores Bullfinch Pyrrhula murina, Tuamotu Kingfisher Todiramphus gambieri and Araripe Manakin Antilophia bokermanni.

The fair will host all the usual attractions including celebrity lectures, trade stands, bird ringing sessions and a birdfair auction.

Last year the fair raised a record £226,000 to support BirdLife's work in saving critically endangered birds around the world. This takes the total raised to date to a staggering £1,929,000.

The British Birdwatching Fair opens at 9am and closes at 5:30 pm from next Friday (August 15) until Sunday 17. Visit www.birdfair.org.uk for more details.