By Charles Haviland
BBC News, Kathmandu
A previously unknown sub-species of bird has been discovered in the southern grasslands of Nepal, scientists say.
The bird was first spotted in a wetland area
The bird is a warbler with a very long tail and slender beak and has been named the Nepal Rufous-vented Prinia.
Scientists say the bird provides an important geographical link between previously-known varieties in Pakistan and India.
But they warn its tiny population means the sub-species is endangered.
The bird was first spotted in 2005 in a wetland area.
But it is only now that taxonomists have decided it is distinctive enough to be described as a separate sub-species.
It has different dimensions from the two other types of Rufous-vented Prinia, and in colour comes between the rich chestnut of its western neighbour and the grey of the one to the east.
Hem Sagar Baral of Bird Conservation Nepal said the find is exciting because while the other two types belong to Pakistan's Indus river basin and the Brahmaputra of north-east India, this Nepalese sub-species fills the gap.
The latest find "appears to form the link" between the two pre-existing sub-species, he said.
The new find brings the number of bird species spotted in Nepal to an exceptionally high 862.
But the conservationists are warning that with habitat loss and degradation, the newly-identified variety is highly threatened, with at most 500 birds currently alive.
They are however elated that it has been found in a reserve which is well monitored by bird-watchers, and are now speculating that there may be more species waiting to be found - new to Nepal, or even to the world.