TWITCHERS have been put in a flap by a sighting of what may turn out to be one of the world's rarest birds.A flock of more than two dozen "twitchers" – bird enthusiasts who will travel many miles at short notice to see a rarity – descended on Minsmere yesterday and more are expected today.

TWITCHERS have been put in a flap by a sighting of what may turn out to be one of the world's rarest birds.

A flock of more than two dozen "twitchers" – bird enthusiasts who will travel many miles at short notice to see a rarity – descended on Minsmere yesterday and more are expected today.

The subject of their attention was a bird which could turn out to be a slender-billed curlew, one of only about 270 thought to exist.

It could be months before experts take into account eyewitness reports and photographs to make a decision on whether it is a slender-billed curlew and not a common curlew.

The former has only been seen on 174 occasions since the year 1900, the last sighting in the UK being at Druridge Bay, Northumbria, six years ago.

Its breeding and nesting grounds of the past 75 years have never been discovered, despite a number of expeditions.

The slender-billed curlew was, in the first quarter of the last century, associated with nesting in Siberia and migrating to north Africa.

But it has disappeared from Siberia and only a few birds have been sighted in north Africa in recent years.

Ian Barthorpe, Minsmere spokesman, said when news of the possible sighting had begun to circulate a few enthusiasts had gathered on the beach near the grazing marsh yesterday morning.

"More are probably on the way although many twitchers are already heading for the Scilly Isles where another rare bird has been sighted," he said.

Chris Durdin, RSPB spokesman in East Anglia, said the slender-billed curlew was "one of the rarest and most enigmatic" of the world's wading birds.

"It used to be more common but was hunted almost out of existence last century," he added.