India’s vultures are disappearing from the country’s skies, declining by as much as 99 percent from their original numbers, with the remainder dying at a rate of more than 40 percent annually, victims of pollution, declining habitat, poisoning, urbanization and a host of other problems, conservationists say.

Although the phenomenon has been documented for more than a decade, nothing appears to be slowing the decline. That has posed a particular problem for the country’s Parsis, a dwindling population themselves, whose religion demands that they leave the bodies of their dead above ground, to be picked clean by the birds.

The Parsis, who fled Persia —the present day Iran — centuries back and made India their permanent homeland, practice the religion of Zoroastrianism. About 100,000 live in major cities like Mumbai, Hyderabad and Kolkata. According to their religious practice, the dead bodies cannot be buried or burnt because the corpses could pollute the Panchabhootam (earth, water, air, ether and fire). Hence their bodies are left in a high-rise ‘Tower of Silence’ to be consumed by the scavengers.

“Unfortunately the vultures have disappeared from our region and a sustained breeding project for vultures has become essential,” said Khojeste P. Mistree of the World Alliance of Parsi and Irani Zoroastrians, in an interview. “The vulture happens to have been the first scavenger of the world and hence they should be brought back for a sustained ecological balance.”

How long there were will be enough Parsis around to satisfy the vultures is another question. According to “Parsi Khabar,” a website for the Parsi community in India, the Zoroastrian sect’s numbers are diminishing because of self-imposed discouragement of intercommunity marriages, leading to inbreeding. Members of the community from Hyderabad point out that by rough estimates there are just 70,000 Parsis in Mumbai and 1,200 in Hyderabad.

Many Mumbai Parsis have been pursuing a plan to breed vultures in captivity. However, Minal Shroff, the chairman of the Bombay Parsee Panchayat, which runs the Tower of Silence, said scientists studying the proposal shelved it, saying it will not be possible since vultures appear to be particularly susceptible to a ubiquitous anti-inflammatory veterinary drug called diclofenac. It is cheap and can be used for treating cattle, buffalo, sheep and goats as well as human beings.

Accordingly, in Assam and other areas, conservationists have started captive breeding programs that face problems, but vultures are notoriously hard to get to reproduce. They are monogamous, mating for life and producing perhaps no more than a single egg per year after reaching breeding maturity at five years of life. Critics maintain that the captive breeding programs are being mismanaged and robbing wild populations as the captive breeders steal eggs from native nests.

Vibhu Prakash, the principal scientist for the vulture conservation breeding program at the Bombay Natural History Society, said some nine species of vultures in the wild numbered 40 million birds in the early 1980s. Today, only about 60,000 birds are left. Nor, says Dr Prakash, are other countries in South and Southeast Asia in any better shape. Vultures have been almost wiped out in Bangladesh, Thailand, Vietnam, Cambodia, Malaysia and Singapore as well as South Asia.

Vultures do not hunt living animals but depend on the carcasses of livestock and wildlife for their primary food supplement. The scavenging birds that way help in keeping the environment clean. And, ugly though they may be, they are an integral link in the natural chain, eating the flesh of carcasses completely and cleanly. The birds thus prevent the spreading of severe diseases like rabies and anthrax among the wildlife, livestock and humans.

A mature vulture may weigh up to 10 kgs and needs almost half a kilogram of meat daily. The most common theory is that the birds are dying from eating meat with high percentages of diclofenac residue. Scientists suspect that the diclofenac remains active for a longer period in the carcasses of treated animals. The drugs reportedly cause dehydration, with the birds soon dying of visceral gout and kidney failure.

“We found that, over 75 percent of vultures which were discovered dead or had died of visceral gout had diclofenac in their tissues,” Prakesh said.

The BNHS launched a rigorous campaign against diclofenac in 2003, 10 years after India introduced the drug. New Delhi banned its use for veterinary purposes in 2006. It is also banned in Pakistan and Nepal. However, researchers believe diclofenac made for human needs is being used for veterinary purposes. Hence, the BNHS continues to pursue the government to warn against its veterinarian use.

Not everyone blames diclofenac. Ajay Poharkar, a veterinarian in the Maharashtra Animal Husbandry Department, argues that malaria is also a major cause of vulture deaths.

“I always thought the diclofenac theory was inadequate,” Pohakar said in an interview. “One vulture requires around 500 grams of meat per day. In that case, there should be very little trace of diclofenac in their bodies.”

Writing in the journal “Current Science” recently, Poharkar cited his experience working with vultures at Gadchiroli, near Nagpur in Maharashtra, arguing that the Gadchiroli farmers are too poor to use diclofenac on a mass scale.

Rather he and his associates found malarial parasites in blood-smear samples from the birds. The Hyderabad based Centre for Cellular and Molecular Biology and the veterinary college in Mumbai agreed.

“It is amazing that the malarial symptoms are quite similar to that caused by diclofenac like shivering, ruffled feathers, respiratory distress, circling movement of the head, greenish watery diarrhea, paralysis and anemia,” Poharkar asserted.

Prakash says that considering the catastrophic decline and the availability of diclofenac in the markets, a captive breeding program appears to be the only way to save the species. In California, the condor, a giant bird with an eight-foot wingspan, had diminished to just 23 birds in the wild before a captive breeding program was got underway. Today, about 200 pairs have been reintroduced into the wild.

“By bringing some vultures into captivity, their lives can be saved and once they start breeding, they would augment the population,” he argues. “The vultures will be released back in the wild once we are sure that there is no diclofenac available in the system.”

The century-old BNHS, recognized as one of South Asia’s most respected wildlife research organizations, has already taken initiatives for the captive breeding program. With the support of international organizations like the Royal Society for the Protection of Birds (UK), the Zoological Society of London and the Peregrine Fund (US), the BNHS runs vulture breeding centers at Pinjore in Haryana, Rajabhatkhawa in West Bengal and Rani in Assam.

The Pinjore center has 120 vultures and Rajabhatkhawa centre has 76 vultures of three species, the Rani center 30 of two species.

“Our objective is to have 50 birds of each of the three species at Pinjore and Rajabhatkhawa and 50 each of white-backed and long-billed vultures at Rani,” said a BNHS official, adding that 75 percent of the birds are to collected as nestlings or juveniles and the rest as adults or sub-adults.

There are critics. Soumyadeep Datta, an environmental activist in Northeast India, argues that the captive breeding of vultures will result in nothing.

“Mature vultures select their partners in the wild and the birds lay eggs in such a way that cannot be arranged in captivity,” Datta said. “They are monogamous birds and they maintain the loyalty of conjugal lives till death. Only one egg is expected from a pair in one season. The caring mother continues its close bond with the baby till the chick attains maturity,” said Datta, who serves as the director of Nature’s Beckon, an Assam based environmental NGO.

“The indiscriminate lifting of chicks from nests, as done by the BNHS people in Assam, will only disrupt the male-female ratio,” he added. “We suspect that collecting babies from the nests will have a negative impact on the sex ratio and the population in our region.”

Datta said that unlike other parts of India, the populations of white-rumped and long-billed vultures have been stable if not increasing. Although the birds are breeding naturally in the state, he said, members of Nature’s Beckon suspect that the BNHS people have captured as many as 100 adult and semi-adult birds in Assam since 2005, with most of them taken to breeding centers of Haryana and West Bengal.

Asad Rahmani, the BNHS director, faced public outrage in Assam when local people protested the capturing of vultures from their localities. Nature’s Beckon has urged the Assam government to stop activities of BNHS people in the region and also demanded an enquiry about the fate of the birds.

Whatever their fate, it is certain that it will take a longtime to restore the native population by captive breeding. Nita Shah, the BNHS vulture advocacy program officer, acknowledges that vultures breed slowly. As they give birth to only one chick a year and a baby takes nearly four years to attain sexual maturity, she said, nobody should hope ‘for the population to be restored to its original size within our lifetime."