Dr David Edwards of the Faculty of Biological Sciences at the University of Leeds and two leaders from tour company, Field Guides, came across a pair of the new species near the Borneo Rainforest Lodge, in the Danum Valley Conservation Area in Sabah, Malaysia, last June.
One of the guides, Richard Webster, was making his way along a 250m canopy-walkway, built to allow visitors to see the tropical rainforest canopy at eye level, when he stopped to examine some flowering mistletoe in a tree, 35 metres above ground level.
There, amongst several familiar species of flowerpeckers - small birds that specialize in feeding on mistletoe berries - was a bird that he did not recognize. Fortunately, Webster managed to take some photographs, which showed an attractive grey bird with bright white arcs above and below the eye, a white throat extending as a broad white stripe down the centre of the belly, and white tufts at the breast sides.
After consulting Dr Edwards, who has been conducting ornithological studies in the region for three years, they realized that this was a species never before recorded anywhere in the world. Edwards said: "The realization that in all probability we had been watching a species unknown to science was an incredible feeling. We were elated because we were on the verge of an amazing discovery, but it was mixed with trepidation in case it was never seen again. It was the kind of moment you dream of - like we'd won the pools and the World Cup on the same day."
Edwards revisited the area several times, but there was no further sign of the birds. The group's findings are reported in the expectation it will lead to further sightings of the bird and its formal scientific description as a new species.
"We hope the announcement of our discovery will lead to our ultimate goal: conservation of the new species and large tracts of its habitat, which is under threat from clearance for oil palm agriculture," said Edwards.
The finding is all the more surprising given its location in Danum Valley, where a scientific research station has been in operation since 1986.
"The discovery of a new bird species in the heart of Borneo underlines the incredible diversity of this remarkable area," said Adam Tomasek, leader of WWF's Heart of Borneo Initiative.
"It further emphasises the importance of the commitment already made by Brunei Darussalam, Indonesia and Malaysia to protect the Heart of Borneo - but also highlights the need to fast-track implementation of these commitments to ensure the many new species discovered in the area survive."
Jean-Christophe Vié, Deputy Director of IUCN's Species Programme said: "This discovery shows once more how little is known about the diversity of life on our planet. 2010 is the International Year of Biodiversity. It is an opportunity to increase our knowledge of nature and its functioning, explain its importance to the wider public, and most of all, undertake action to reduce the current threats in order to allow thousands of more discoveries like this one in the future."
The species is so little known that it has yet to be given a scientific name. The findings are published today in the latest issue of the Oriental Bird Club's magazine, BirdingASIA.
Jessica Kwok and Ronaldo Ichiyama, International Spinal Research Trust (Feb 2018), £94,450
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