Save the vultures may not be as appealing a slogan as save the elephants, save the blue whales, or save the pandas, but it may well be in mankind’s best interests to overcome this species bias. The case of vultures is also symptomatic of our inability to look beyond the immediate effect we have on the environment.
In some areas of India, the vulture population dropped by over 90% in the decade between the years 1990 and 2000. This didn’t happen because the local human population suddenly decided to kill vultures, it happened because humans started using an anti-inflammatory drug, diclofenac, on their cattle. The drug had proven harmless to both cattle and humans, but effective in protecting cattle in a country where cattle are sacred. The use of the drug increased explosively, and the farmers were happy.
What no-one thought about, or even considered, was that the drug might have a devastating effect on other species. Despite being harmless to cows and humans, birds that consumed animals treated with diclofenac suffered kidney failure and died within weeks.
It reminds me of the Monsanto disaster of promoting their product called “RoundUp”, which worked effectively in killing weeds without affecting Monsanto seeds, but which killed every other plant within wind-distance range, which was not a Monsanto genetically-developed product. The only difference is that, in the Monsanto case, the action was deliberate, whereas in the diclofenac case it was ignorance born of lack of adequate research and disinterest.
Decimating the vulture population in India almost immediately affected humans. Vultures are nature’s sanitation service. Their diet consist largely of rotting livestock carcasses – numbering 30 million a year in this cattle-revering country. A group of vultures can polish-off a cow’s carrion in around 40 minutes. Their strongly acidic digestive track destroys most germs.
Without vultures, carcasses attracted feral dogs and rats, which carry rabies and other diseases that threaten humans. In addition, these animals are far less efficient at finishing off carrion. The resulting carcasses that are not efficiently removed from the environment by vultures, are full of pathogens that then spread to the drinking water. The result in these vulture-decimated areas of India was a 4% rise in human mortality rates.
Images of blood-spattered bills may not be the best advertisement for protecting a species but it pays to look a little beyond first impressions, and consider the longer term consequences of our actions.
The abrupt demise of the vultures in these districts of India made it possible to quantify their impact on public health. A study carried out by professors from the University of Warwick, in England, and the University of Chicago, used a statistical model to compare changes in the human death rates in districts with habitats suited to vultures, and in districts with less-suited habitats, as the use of diclofenac surged. In the districts with suitable habitats, which lost the majority of their vultures, more people began to die, as the sales of diclofenac increased. The effect was the greatest in urban areas with large livestock populations. The cause and effect was blatantly obvious.
The authors calculated that between the years 2000 and 2005, the loss of vultures caused 500,000 additional human deaths.
“Keystone species”, like the vulture, hold ecosystems together, and conserving these species, and perhaps all species, should become a major priority. We may not like to think about it, but our own ultimate survival almost certainly depends on it.