Ornithologists discover 18 species in three years despite forest destruction

What do the chestnut-eared laughing-thrush, the Mekong wagtail and Lulu's tody-tyrant have in common? Answer: nobody knew they existed until last year. They are just three of 18 bird species discovered since the start of the 21st century, mostly in the rainforests of Asia.

The world's range of birds is growing, confounding fears that environmental pressure will cause a decline. A total of 28 new species have been described in scientific journals since 1998, and research could add many more to the world total of about 9,700.

But these "new" birds may be endangered because their populations are low and confined to small areas. Nine of the 28 were found in Asia, where 323 species out of a total of 2,700 have been declared threatened, mostly because of habitat destruction.

Details of the discoveries – all in South America and Asia apart from two in Africa and two more on Indian and Pacific Ocean islands – are published in the magazine Birding World. Steve Gantlett, its editor, said: "Many of these discoveries result from the world becoming much more accessible – ornithologists can go to remote places virtually out of reach a few decades ago.

"They also reflect increased expertise at identifying species by their calls – often the only way of detecting them in dense tropical rainforests. Part of the reason they have just come to light is that they have very small ranges, which makes them vulnerable if their habitat comes under pressure.''

Nigel Collar, of the conservation group BirdLife International and editor-in-chief of The Threatened Birds of Asia, said: "The steady flow of discoveries shows that we simply have not been looking hard enough in the past.''

New species include Torotoroka scops owl (Otus madagascariensis), discovered in Madagascar in 2000, and the Bukidnon woodcock (Scolopax bukidnonensis), found in the Philippines last year. Discoveries this year include the llpahuayo antbird (Percnostola arenarum) in Peru; and the bald parrot (Pionopsitta aurantiocephala) in Brazil.