Spare a thought, if you can, for the humble vulture, that airborne scavenger of death and decay. It may not have the cuddly, fluffy appeal of the giant panda or other endangered species that get us digging in our pockets for donations. But the vulture seems to be going the way of its prey - past the point of no return. A year-long research project in Thailand has failed to locate a single vulture in the wild. Not even the migratory species that used to fly south in winter to Thailand, from mountainous climes to the north, have showed their bald-headed faces. The researchers concluded gloomily that the only place in Thailand where you can still see a vulture is in the zoo. The last of the wild variety sighted in the country met a sorry end. In 1992, about 50 red-headed vultures were poisoned by hunters in a wildlife reserve. Vultures were common in Thailand's forests and farmland several decades ago, and were even known to gather at a Buddhist temple in Bangkok, presumably to feast on dead dogs. But economic development and industrialisation hasn't been kind to Thai wildlife. The populations of tigers and other wild animals have fallen dramatically in recent decades. Fewer predatory animals result in fewer carcasses left behind for the vultures to feast on. The birds generally don't attack healthy animals: they wait until the prey is sick or dying before they swoop down. The Thai researchers attached tiny radio transmitters to vultures in Cambodia, and tracked their movements by satellite. They hoped to learn if the birds still congregated in Thailand, as this might reveal a hidden native population. But none turned up there. The researchers seem to have taken this blow on the chin, judging by the comments made by the lead biologist, Narit Bhumipakphan of Kasetsart University in Thailand. He told The Nation newspaper last week that he hadn't expected much public sympathy for his doomed hunt. 'Thais are almost unaware of the bird's disappearance,' he said. He explained that the reason was that vultures 'have been regarded as a bad omen since ancient times. So, far from being concerned about their extinction, people are happy not to see them'. The same cannot be said in India, where vultures have long been used for 'sky burials' by the Parsi minority: human corpses are laid out on rocks to be picked clean by the descending scavengers. Even there, it's becoming harder to attract enough vultures to finish off the job. Native populations have been reduced by the practice of giving drugs to farm animals to prolong their work lives. The animals eventually die, and the vultures that feast on their remains are sickened by the drugs, and die.