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In
danger of losing out
By Fareeha Irfan Ovais
 Since
the last decade, scientists have been baffled by the dramatic decline
of vulture species in the Indian subcontinent. There are about nine
species of vultures that inhabit South Asia and, of these, three have
undergone an alarming loss in numbers, leading to a serious
environmental problem.
The oriental white-backed vulture was once described as the commonest
species of vulture in the Indian subcontinent, widely distributed in
Punjab, Sindh and NWFP. Unfortunately, surveys done in 2003 show that
its population has declined by almost 99 percent. The number of the
long billed vulture has decreased by more than 97 percent and the rare
slender billed vulture is also declining rapidly. All three species
are now listed as critically endangered by The World Conservation
Union — the highest level of extinction risk.
Worried and perplexed, scientists have been trying to offer various
explanations, not sure what is causing this dramatic loss. Recently,
however, a scientist at the Washington State University, Lindsey Oaks,
working with the Peregrine Fund presented information on the causes of
death from three colonies in Pakistan.
The researcher found that the dead birds suffered from severe gout and
the birds with gout had high level of a veterinary drug called
Diclofenac in their kidneys. Diclofenac is a non-steroidal
anti-inflammatory painkiller used widely in the last couple of years
to treat livestock in India, Pakistan and Nepal. It appears that
vultures were exposed to Diclofenac by eating the carcasses of
livestock treated with this drug. Residues of the drug then built up
to such high levels in the vultures that they suffered kidney failure
and eventually death. Research shows that contamination of even one
percent of livestock carcasses is sufficient to have caused the
vulture population crash.
 These findings are
very exciting and seem to explain much of the vulture mortality of the
colonies studied in Pakistan. In India, the geographical pattern and
spread of the disease along with the blood/tissue analysis of the dead
birds seem to indicate an infectious disease as the likely hypothesis
although no disease has yet been identified. This does not rule out
the possibility of Diclofenac or some other toxin playing a role. It
is likely that a combination of factors has led to vulture decline,
with Diclofenac delivering the deadly blow.
This vulture loss is bound to have serious consequences for the food
chain and the ecosystem since vultures play an important ecological
role of cleaning up and removing dead livestock and even human
corpses. A vulture decline may mean that dead corpses remain lying
around and decay slowly. Alternatively, there will be an increase in
numbers of other scavengers such as feral dogs that have already
multiplied, leading to greater incidence of diseases including rabies.
The Parsi community in India is especially worried since they rely on
the vultures to dispose of their dead.
Conservationists on both sides of the border are pressing their
governments to ban Diclofenac. The Indian state of Gujrat is the first
state to have taken the decision to stop the purchase of the drug.
However, even if the drug is banned, it is likely that its underhand
usage will continue and it will remain on shop shelves for a long
time.
The problem is so urgent, with vulture communities down to less than
five prevent of their numbers a decade ago, that even if Diclofenac is
banned immediately the vultures are likely to go extinct. Some rough
estimates suggest that the oriental white backed vulture might go
extinct in as little as five years. The other two species are already
critically endangered.
Conservationists warn that the only way to save the vultures is to
initiate a captive breeding programme which, if successful, can be
used to reintroduce vultures into the wild. But time is running out
even for that. Unless action is taken now, it will become impossible
to find enough vultures to establish stocks for captive breeding.
Organizations involved in vulture conservation in India, Pakistan and
Nepal have joined hands to protect the declining vultures. These
organizations are pressing their governments to ban Diclofenac
immediately. Moreover, they have also agreed to initiate obtaining,
holding and breeding the three gyps species of endangered vultures in
captivity as a safety measure until the threat of Diclofenac is
removed from the environment.
Credits:
©1997-2007
Wildlife of Pakistan-All Rights Reserved.
Updated
February 25th, 2007 |
