A little brown bird in Thailand has a lot of ornithologists celebrating its rediscovery, 139 years after its original identification. In 1867, a single specimen of a Large-Billed Reed-Warbler (Acrocephalus orinus) was collected in the Sutleg Valley near Rampoor, Himachal Pradesh, India.

In many ways, this new reed-warbler resembled other better-known reed-warblers. It had drab brown upper-parts and creamy colored under-parts. But in a few ways, the specimen was distinct. It had significantly shorter wings and a longer beak when compared to other reed-warblers. So based on these characteristics, it was declared a new species.

Then, for more than a century, there were no signs of the Large-Billed Reed-Warbler. Experts began to question its status as a distinct species. Could it have been a short-winged, long-beaked individual belonging to a better known species?

Today, molecular genetics offers scientists a precise tool in determining relatedness among species. A recent study that examined the genetic material of the 1867 specimen revealed that it was indeed a new species. In fact, being the only know specimen of the species, it was one of a kind. That is, until now.

BirdLife International has recently announced the re-discovery of the Large-Billed Reed-Warbler by ornithologist Philip Round. While banding birds near Bangkok, Thailand, Dr. Round came across a bird that was quite unique. To verify the identity of the bird (while ensuring it no harm), he took photographs and two feathers for DNA analysis.

Tests confirmed that the bird belonged to the same species as the 1867 specimen, it was the first Large-Billed Reed-Warbler identified in 139 years.

The rediscovery, although exciting, represents only the first step in the longer process of protecting the species. Virtually nothing is known about the bird and a great deal of information about habitat, range, and population size is needed to ensure its continued survival:

"A priority now is to find out where the Large-billed Reed-warbler’s main population lives, whether it is threatened, and if so, how these threats can be addressed.” —Dr Stuart Butchart, BirdLife International

Find out more: Indian Warbler 'Lost' for 139 Years Makes Spectacular Return (BirdLife International)

Photo © Philip Round / The Wetland Trust and Birdlife International.