By Alex Kirby
BBC News Online environment correspondent
In a clarion call to save hundreds of Asian bird species from extinction, ornithologists have launched a crisis guide to the threats the animals face.
Caerulean paradise flycatcher: Confined to one forest
(Image by J Riley)
It reveals logging and plantations as the greatest dangers to bird survival.
The number of species at risk is 324 - this is about 12% of all Asian birds.
Scientists say there may be no hope even now for 11 of the species.
The guide is published by BirdLife International, a global network of conservation groups in 100 countries.
Financial support for the guide came from the Critical Ecosystem Partnership Fund (CEPF), which combines Conservation International, the Global Environment Facility, the Japanese government, the World Bank and a private US charitable foundation.
CEPF has provided more than $29m to 180 conservation projects in Asia, Africa and Latin America.
Launching the guide, Saving Asia's Threatened Birds, Princess Takamado of Japan said: "Asia is blessed with a uniquely varied and abundant number of bird species: treasures we are in danger of losing.
"Now, as environmental issues grow into global concerns, it is imperative that we act with intelligent integrity."
The guide says the 41 Asian birds classified as critically endangered by IUCN-The World Conservation Union "already teeter on the brink of extinction".
Those thought possibly extinct include the Javanese lapwing of Indonesia and the pink-headed duck, a native of India and Burma.
The Bali starling is one of six species now reduced to fewer than 50 mature individuals in the wild, a level which reinforces concern for their chances of survival.
BirdLife says a major priority should be more than 100 sites which are critically important for globally threatened birds and yet remain unprotected.
Two of the most important are the small Indonesian island of Sangihe, and the Siburan forest on the Philippine island of Mindoro.
Sangihe has three critically endangered species, including the caerulean paradise flycatcher, found only in one very small unprotected forest.
Princess Takamado: "Imperative that we act with intelligent integrity"
Siburan is the main home of the critically endangered Mindoro bleeding-heart, a type of pigeon.
Asia's most important bird habitat, the guide says, is tropical lowland moist forest, which holds more than half the continent's threatened birds.
It says: "Commercial logging, clear-felling for paper production and plantation establishment are the biggest threats to Asia's birds."
Indonesia, with 117 globally threatened species, has more than any other Asian country, with China next at 78. India has 73 species and the Philippines 70.
The second largest threat, BirdLife says, is the disturbance or destruction of wetlands, home to species like the Siberian crane and black-faced spoonbill.
Migratory species like the spoon-billed sandpiper and the spotted greenshank also depend on wetlands, and are threatened as well by large land reclamation projects, especially along the coast of the Yellow Sea of Korea and China.
Other significant threats include hunting for food and for the pet trade. The guide lists what ornithologists believe is needed to ensure the survival of each species in 33 priority habitat regions.
Bali starling: Few than 50 adults birds left
(Image by M Edwards/Still Pictures)
BirdLife says it is best to concentrate efforts on these threatened habitats because often saving one of them will benefit several distinct species.
Recommendations in the guide include protecting wetlands on migratory flyways, including the demilitarized zone between North and South Korea, which it says should become a transboundary peace park.
It also urges conserving the remaining lowland tropical forests of Malaysia and western Indonesia, protecting key sites in the Philippines and eastern Indonesia, and better implementation of the UN's Convention on International Trade in Endangered Species (Cites).