GRIFFON vultures are dying across India, apparently succumbing to a
mysterious illness. Wildlife experts are becoming increasingly concerned about
the viability of one species in particular. But for India’s ancient Parsee
religion the vultures’ decline poses a more practical problem. Parsees rely on
vultures to dispose of their dead, and the bodies are piling up.
At Bombay’s biggest Parsee funerary site—a high-walled enclosure open
to the sky where the dead are laid out—some corpses have lain uneaten for
three years, and the stench and possible spread of infection are becoming a
problem. The Parsees have called in Western experts, and are considering
sponsoring an unprecedented breeding programme to bring the birds back. If
successful, the plan might save not just their faith, but also the vultures of
India.
Parsees are the religious descendants of the Zoroastrians of ancient Persia.
They believe that earth, water and fire are sacred and must not be defiled by
corpses. So they put their dead in funerary sites where hundreds of griffon
vultures perform the disposal job. The funerary site of the prosperous Parsees
of Bombay is known as the Towers of Silence, a well-known landmark in the city
next to the Hanging Gardens Park on upmarket Malabar Hill.
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But vultures from the griffon genus have all but disappeared across much of
India over the past few years
(see p 32). Poisoning with the insecticide DDT,
widely used in India, was initially suspected. But that would be unlikely to
affect only one genus of vulture, or to cause such an abrupt and widespread
die-off, says Andrew Cunningham, a veterinary pathologist with London’s
Zoological Society. A more likely culprit is infectious disease, and last spring
Cunningham found signs of viral infection in some vulture carcasses.
When Bombay’s Parsees realised there was a problem last year, they approached
Jemima Parry-Jones, head of Britain’s National Birds of Prey Centre in
Gloucestershire. “They thought the vultures had just gone elsewhere,” she says.
They asked her if it might be possible to trap vultures inside the Towers of
Silence with a net.
“First I needed to see the problem,” she says. Initially, the Parsees refused
to admit her. Only low-caste workers can enter the Towers, and even Parsee
leaders have not been inside for centuries, says Parry-Jones. But in February,
she became possibly the first female outsider ever to glimpse the interior.
“There were bodies in every state, from fresh to extremely decomposed,” she
reports. “Not much has been eaten in there for three years. They desiccate in
winter, but I dread to think what happens in the summer monsoon.” And the
corpses could become a health problem. Smaller birds, such as crows and kites,
are now flocking to the Towers and, unlike vultures, fly away with their food
and can drop bits.
Parry-Jones’s assessment was not encouraging. Holding vultures inside the
towers is not a solution, she says. The birds need space, and a varied
diet—too much of one species is bad for them. Another option that
Parry-Jones is discussing with the Parsees is to move their funerary site. “If
they sold the Bombay property, they could easily build a new disposal site, and
a huge aviary, outside town,” says Parry-Jones. With more space, vultures could
be bred in captivity. “About 200 vultures would be enough,” she says.
Captive breeding has never been attempted with such slow-breeding birds. “It
would be a captive breeding programme to die for,” says Parry-Jones. But with so
few griffons left, it might not be easy, or ethical, to take so many from the
wild.
And there remains the problem of the mystery disease that is killing wild
vultures. It would probably infect captive birds too. Researchers in the US and
Europe have offered to help pin down the disease. But concerns in India over
Western companies patenting genes from native species have meant that, so far,
no vulture tissue has been allowed out of India for analysis. Indian scientists
are now looking at bacteria, fungi and viruses in carcasses, as well as
examining the pathological damage.
If the disease can be identified, finding a treatment for the captive
vultures might not be difficult. The International Food Policy Research
Institute in Washington DC says chicken production in India grew rapidly during
the 1980s and 1990s and there are well-documented cases of avian infections
jumping from battery hens to wildlife.
If they are the source of the disease, says Parry-Jones, “then the poultry
industry might have a treatment, or a vaccine”. Parry-Jones, who helped to bring
the Mauritius kestrel back from the brink of extinction through a breeding
programme, hopes that if vultures can be bred successfully, this might be a way
to start repopulating India with vultures.