By Alex Kirby
BBC News Online environment correspondent
A small songbird believed to have become extinct more than a century ago has been found alive and well in Fiji.
Back from oblivion, and in good voice
A team from BirdLife International discovered the bird, the long-legged warbler, after hearing its distinctive and haunting call in a mountain valley.
BirdLife says the 12 pairs of warblers it has seen are safe for the moment in their remote home in the dense forest.
But the birds are at risk from forest clearance elsewhere, and from mongooses introduced to the islands to kill rats.
The warbler is known also as the long-legged thicketbird, in recognition of its preference for living in dense undergrowth.
Given up for dead
It used to be called the spirit bird (manu kalou) by local people, perhaps because of its singing.
Only four specimens were collected, between 1890 and 1894, since when there had been no confirmed sightings of the bird. Despite unconfirmed sightings within the last 20 years, BirdLife believed the warbler was extinct.
The warbler's forest home
But a year into a survey of Fiji's rare birds, funded by the UK's Darwin Initiative, it turned up again on Viti Levu, the largest island in the group.
Vilikesa Masibalavu of BirdLife was the first to identify the warbler. He said: "I heard a loud song which was different from any other Fijian bird."
His colleague Guy Dutson said: "At first incredulous, I soon realised this was indeed the bird we had been searching for all this time."
After that initial discovery, nine pairs of warblers were found along a two km stretch of stream with dense thickets of undergrowth in Wabu, a forest reserve. Another pair was later found in a logged forest.
BirdLife says this shows there are locally high population densities at an altitude between 800-1,000 metres (2,600-3,300 feet) in the unlogged forest. Two of the pairs were seen with recently-fledged young birds.
Reversing the trend
Guy Dutson said: "The long-legged warbler is a very secretive species but now we know its song, we can find it and make our first assessment of its conservation needs.
"Its rediscovery is a rare beacon of hope when all too often birds are becoming extinct in their natural habitats, especially those endemic to small islands.
"We must now work to ensure this bird does not disappear after managing to hide from us for so long, and I hope to make sure it gets the protection it deserves."
BirdLife, a global alliance which works in more than 100 countries, says most Fijian forests are unprotected and at risk from logging or conversion to mahogany plantations.
It says its research shows degraded forest is unsuitable for the warbler and for many other birds.
Mongooses have caused the extinction of all of the ground-nesting birds on the main Fijian islands.