A team of scientists from Laos and Sweden has discovered a small colourful bird living in the rocky forests of Laos and Vietnam .

Director of the Division of Forest Resource Conservation, Mr Bouaphanh, said “The limestone leaf warbler has a unique call, setting it apart from other warblers. The warbler was found in limestone outcrops in Khammuan, Borikhamxay and Savannakhet provinces, which are home to many new species.”

Mr Bouaphanh said the warbler was found by a team of scientists from the Division of Forest Resource Conservation, Wildlife Conservation Society, Swedish University of Agricultural Science, Swedish Museum of Natural History, and BirdLife International.

They teamed named their discovery the “limestone leaf warbler” because it breeds in limestone karst environments – a region known for unusual wildlife. It is similar to other warblers in this area of Southeast Asia , except for its distinct call and slight size differences.

A description of the new species is published in the journal IBIS (The International Journal of Avian Science).

“The discovery of this new species is very exciting and underscores the importance of this limestone region for conservation,” said Mr Bouaphanh.

“With increased cooperation from universities and biologists, the limestone range of Laos is revealing itself to have lots of unusual wildlife.”

The tiny bird is greenish-olive with a yellow breast and striped crown. Although it looks similar to other warblers, it is smaller with shorter wings and a larger bill than its closest relative, the sulphur-breasted leaf warbler. According to the study, the bird has a loud and distinct call that first alerted the biologists that the bird may be new to science.

Mr Bouaphanh said scientists presume there are many limestone leaf warblers in this region. But its habitat isn't without threats. Many parts of the species' native forests have been cut for fuel or timber collection. The Lao government is making an effort to reduce the threats that limestone leaf warblers and other wildlife face in this region.

Earlier this year from this same region, the Department of Forestry and scientists described the bare-faced bulbul – another species previously unknown to science.

Also from the same area the kha-nyu was described in 2002, a newly discovered species of rodent so unusual it represented the lone surviving member of an otherwise entirely extinct family.

Three years earlier a unique striped rabbit was described, also new to science.