ONE OF Britain's rarest birds was spotted in Weymouth this week giving hope to conservationists that a long-term decline has been reversed.

The bittern, or bog blutter, as it's known to twitchers, is a secretive and difficult to spot member of the heron family which is well camouflaged by the reeds in which it lives. Bird spotters listen out for its "booming" call, a low foghorn sound which can be heard up to three miles away made by males to attract females and announce their territory.

Bittern numbers fell to an all-time low in 1997 because of the draining, destruction and neglect of the bird's natural reed bed habitat.

A multi-million-pound conservation project has seen the restoration of these habitats and a gradual growth in bird numbers. Weymouth's nature reserves at Radipole and Lodmoor, which are part of the project, usually get one or two visits by a wintering bittern every year, but this year's sighting is the earliest on record.

Keith Ballard, RSPB Weymouth reserves warden said: "The bittern spotted earlier this week may be a young bird that has flown in from the east of England looking for its own territory.

"We are optimistic that by creating the right conditions here in Weymouth, bitterns will move in permanently and we will have played our part in saving them from extinction in this country," he said.

National conservation work to save the species from extinction has included the creation of new reed beds and better management of existing ones at 19 sites throughout England.

Much of the £4 million needed for the work has been supplied by the EU LIFE Nature, a programme dedicated to the establishment and protection of threatened habitats or species of continent-wide importance.

Research by the RSPB and English Nature shows that the project is a success, with at least 42 booming males recorded across the UK - nearly four times the number six years ago.

"We have done quite a lot of work at Lodmoor to improve the quality of the reed bed and the water, and it has paid off because this is the first time we've had a bittern here in the summer," said Keith.

And, he says, if a bittern decides to make its home in Weymouth it would prove a real draw for tourists hoping to catch a glimpse of this fascinating bird.

"If national bittern numbers continue to increase we could have a breeding bird in Weymouth before long," he said.