Though it’s long been chirping away mere kilometres from Phnom Penh, a type of small songbird with a rust-colored head has only just been discovered to be a new species.

Researchers announced yesterday that in the past year they had found more than 100 birds belonging to the species they are calling the Cambodian tailorbird, or Orthotomus chaktomuk – including one male within the capital’s city limits at Choeung Ek.

“It’s special to find a new species of bird,” Simon Mahood of the Wildlife Conservation Society, the paper’s lead author, said. “It’s especially interesting to find one that lives so close to people, not in some remote area.”

Mahood began to suspect researchers were dealing with an entirely unique species in 2012, when he was unable to identify the species of a tailorbird in a photo that his colleague and co-author, Ashish John, took at a partially flooded construction site outside Phnom Penh.

After further investigation, the team of WCS, BirdLife International and others determined that slight differences in these birds’ colouration and song patterns, and the fact that they did not mix with similar birds in the same area, demonstrated they were a new species.

Probably one reason the birds had not been classed as a separate species before is that they “usually stay within dense vegetation”, the researchers write in their paper.

“The habitat and the species’ skulking habits would more often than not render it invisible to the casual would-be observer.”

While similar species are found elsewhere in the region, the chaktomuk so far only has been found in Cambodia’s southeast.

But researchers warn this habitat may be shrinking due to the impact of agriculture and hydrodams on areas of “floodplain scrub”, and have recommended the International Union for Conservation of Nature class the species as “Near Threatened”.