Vultures Are Disappearing
Vultures are portrayed in cartoons as villains and less friendly characters. In most cartoons, the scavenging bird symbolizes danger and death coming. But, in reality, these birds play a vital role in the balance of the food web. And sad to say, vultures in some parts of the world are in danger of disappearing. If this happens, the world’s food web will not be the same again.
New research from University of Utah biologists reveals that populations of most vulture species around the world are now either declining or on the brink of extinction.
What is causing the decline?
The biologists said the primary threat to vultures is the presence of toxins in the carrion, bodies of dead animals, they consume. Poisoning was ruled out as the greatest external threat to vultures.
Poisons Come in Many forms
The study pointed out that poisoning is the greatest extinction risk facing vultures, and impacts 88 percent of threatened vulture species. Poisons come in many forms and are cited in different parts of the world.
In North America, the California condor, a vulture, declined in numbers which alarmed conservationists and biologist in 1982. Surprisingly, vultures died of poisoning by consuming toxic lead bullet fragments in the gut piles left behind by hunters after animals had been field-dressed. Thanks to conservation efforts, from 22 in 1982, the population of condors now is around 400.
Another form of poison was reported in India. More than 95 percent of vultures disappeared by the early 2000s. It was not ruled out that diclofenac, a veterinary anti-inflammatory drug that relieved pain in cattle, poisoned the vultures. A dead cow carcass attracts hundreds of vultures. And if the cow was treated with diclofenac, hundreds of vultures would die. Eventually, an international efforts led to the total ban on veterinary diclofenac use.
In sub-Saharan Africa, affordable poisons used to control predators, such as lions or jackals are blamed for massive poisoning of the birds. For example, an elephant carcass poisoned in Namibia in 2007 killed as many as 600 vultures.
The Dangers When Vultures Are Gone
Scavengers like vultures keep ecosystem free of the bodies of dead animals, or carrion. Scavengers break down this organic material and recycle it into the ecosystem as nutrients. Extinction of vultures can create an imbalance in the food web.
According to biologists Evan Buechley and Çağan Şekercioğlu, the loss of vultures can allow other scavengers to flourish. Worse than that, proliferation of such scavengers could bring bacteria and viruses from carcasses into places where humans live.
In the absence of vultures, crows, rats, and dogs may grow in number and thus dominate the remaining vultures. Dogs will rule when vultures are nowhere to be found. This is bad news for it is known that changes in populations of certain animal groups can upset the balance of the food web.
In addition, vulture decline imperils humans too. One commendable trait of vultures is, they serve as a barrier to prevent diseases from proliferating in dead animals and passing on to humans. One good learning example for this is the rabies outbreak in India that killed 48,000 people from 1992-2006. The decline of vultures led to the surge of feral dogs. These dogs fed on disease-ridden carcasses, and that led to the rabies outbreak.
Extinction Can be Countered by Investing in Vulture Conservation
Based on the experiences of the past, particularly the rabies outbreak in India and the sharp decline of the Californian condor, something must be done to counter the possibility of extinction of vultures. The story of the condor conveys a message of recovery. In India, biologists believed rabies was only one of the many potential diseases that vultures had helped regulate. The outbreak may have not happened in the first place if there was no decline in the numbers of vultures.
Most importantly, the biologists stressed on investing in vulture conservation.
Buechley says “the better solution is to invest in vulture conservation here and now, in order to stem incalculable damage from trophic cascades and increased human disease burden in the developing world.”
