A wake of vultures perches on the bare branches of a towering tree, dark shapes silhouetted against a pale sky, sharp beaks and talons ready to tear apart a dead cow laid out in a Cambodian jungle clearing.
This manmade "vulture restaurant" is part of efforts across Asia to save the critically endangered bird from extinction. Now there are tentative signs they may be paying off.
The population of vultures in Cambodia has doubled to 300 from as few as 150 in 2004. In India, they are still dying off, but their rate of decline has fallen.
These super scavengers may be regarded as messengers of death and doom, but in Asia, it is they who have suffered one of the natural world's greatest population crashes of recent times.
From tens of millions, numbers of the three main species have plummeted to well below 60,000, says British expert Richard Cuthbert. They have gone extinct in several countries, including Thailand, Vietnam and Laos, and are still declining outside of Cambodia.
While the greatest losses have been in Asia, most vultures outside the region are also deemed critically endangered or threatened.
Scientists say they will probably never fully revive; they were once so numerous in Cambodia that airplanes had to dodge flocks of them. But some reasons for hope have emerged.
In South Asia, the decline of the oriental white-backed vulture has been slowed by a ban on the use of a painkiller in livestock. Diclofenac, widely prescribed by veterinarians in India, Pakistan and Nepal, proved fatal to vultures, which died of acute kidney failure after eating the carcasses of animals treated with it.
In India, they were as part of the landscape as the cows nonchalantly wandering the streets, helping to prevent the spread of disease by vacuuming up carrion. Their decline has been so catastrophic that the Parsis, a religious group that offered their dead to vultures on raised platforms _ the "towers of silence" _ now must use giant solar reflectors to speed up the decomposition of corpses.
"I'd say we are on the border of a red-orange alert as far as extinction. There is some improvement but we have a long way to go," says Cuthbert, the principal conservation scientist of the Royal Society for the Protection of Birds.
A study published in May showed the proportion of cattle carcasses in India contaminated with diclofenac dropped by more than 40 percent in the two years after the ban was introduced in 2006, Cuthbert said. The annual rate of decline for the white-backed vulture is estimated to be about 18 percent, down from 40 percent before the ban.
But the human form of the drug _ an anti-inflammatory medicine _ is still often used by veterinarians, with some pharmaceutical companies even offering convenient, "cow-sized" doses.
India, Nepal and Pakistan have set up breeding centers, hoping to release chicks when the environment is deemed safer. They also have vulture restaurants, which offer drug-free carcasses. Nepal launched a 10-year Saving Asia's Vultures from Extinction program this year and declared a number of diclofenac-free zones.
The drug is rarely used for livestock in Southeast Asia. "We're trying hard to take steps to make sure it doesn't enter the food chain," says Jonathan Charles Eames, regional head for Britain-based BirdLife International.
The greatest threat here has been a loss of food: falling stocks of wild mammals, because of hunting, and of free-roaming cattle as farmers turn to more intensive husbandry and fear theft of their beasts.
"Before 1970, when I was young there were so many vultures in this area. I could see them wherever I went," recalled 82-year-old Pha Noung in the northern Cambodian village of Dangplat, pointing his finger in every direction. "Then almost none. Now, some are coming back."
Down a forest track near his village, the New York-based Wildlife Conservation Society has set up one of six spots in Cambodia where vultures are given food and thus can also be more easily counted. The World Wide Fund for Nature, BirdLife International and the Cambodian government are partners in the nationwide effort.
Song Chansocheat, a Wildlife Conservation Society project manager, says villagers now have a stake in preserving the vulture. They are hired at $2.50 a day to protect nests. They also earn income from foreign bird watching groups, setting up their tent sites and selling them food for the vulture restaurants _ including old or injured cows at up to $200 a head.
But an increasing number of vultures are dying of poisons used by hunters to kill fish and jungle animals, while loggers continue to destroy nesting habitat. Impoverished villagers also sometimes eat decomposing, possibly diseased, cows found in the forests, leaving less for vultures, Song Chansocheat says.
So the restaurants are seen as vital, the bleached, meatless rib cages and skulls, evidence of feasts past.
Recently, as the forests woke up to the chatter and songs of other birds, vultures settled on tree branches above the cow, killed a day earlier. Others, high above, rode the thermals in graceful circles.
From a high watchtower, ranger En Sophal peered through his binoculars, smiled and took notes: "50 white-backed, 11-red-headed, 6 slender-billed: 67 vultures sighted."