International Vulture Awareness Day: The importance of vultures

Today is International Vulture Awareness Day. That makes it a fitting moment to recognize the crucial role these birds of prey play in our world.

Vultures, long maligned as harbingers of death, are emerging as unsung heroes in the field of public health. In India, their precipitous decline in the 1990s—caused by the veterinary use of the drug diclofenac—triggered an alarming rise in human mortality. The figures are staggering: over 500,000 excess deaths were recorded between 2000 and 2005 in areas once home to these carrion-feeding birds.

Once ubiquitous across the Indian subcontinent, vultures played a vital role in keeping the environment clean. They feasted on livestock carcasses, reducing the spread of pathogens and controlling populations of other scavengers, such as feral dogs, that are less efficient in curbing disease. But as diclofenac use surged in 1994, vulture populations plummeted by over 95%, and with their disappearance came an unexpected and lethal sanitation crisis. Rotting carcasses were left to contaminate water supplies and sustain rabies-carrying dogs.

Research, set to be published in the American Economic Review by Eyal Frank and Anant Sudarshan, highlights the dire impact of this collapse. Analyzing health data from over 600 Indian districts, the study found that areas with large vulture populations prior to their decline saw a 4.7% rise in human death rates after 1994. The economic damage, estimated at $70 billion annually, underscores the immense value vultures bring to public health—something only appreciated in their absence.

The study’s implications extend beyond India. In Pakistan and Nepal, vultures faced similar fates due to diclofenac, but Nepal’s stronger regulatory response has led to a recovery in recent years. Africa, too, has seen vulture populations dwindle, though there the threat comes from poisoned carcasses laid to kill predators like lions and hyenas. In contrast, North American vultures remain relatively stable.

The plight of vultures serves as a powerful reminder: the loss of keystone species can have cascading effects that reverberate through ecosystems, impacting human life in ways not always immediately visible. The economic and public health toll of their decline in India offers a cautionary tale about the unintended consequences of failing to protect biodiversity—a lesson that extends to many species globally, whether majestic or maligned.