Eyal Frank, Anant Sudarshan
Scientific evidence suggests the Earth is undergoing a mass extinction of species, caused by human activity. Quantifying the social costs of losing non-human species is necessary to manage biodiversity and target conservation resources. In this paper, we show that the functional extinction of vultures in India increased all-cause mortality because of a negative shock to sanitation. Vultures are efficient scavengers and feed only on carrion. In India, these birds historically provided an important public health service by removing livestock carcasses from the environment. In the mid 1990s, vultures experienced the fastest population collapse of a bird species in recorded history. The cause of death was unknown until 2004 when it was identified as poisoning from consuming carcasses containing traces of the painkiller diclofenac. Originally used to treat human beings, the expiration of a patent led to a dramatic fall in the price of diclofenac, the development of generic variants, and its entry into the veterinary market in 1994. We exploit this event to study the costs of losing vultures. Using habitat range maps for affected species, we compare high to low vulture suitability districts before and after the veterinary use of diclofenac. We find that, on average, all-cause death rates increased by more than 4% in vulture-suitable districts after these birds nearly went extinct. We also find evidence suggesting that feral dog populations and rabies increased, and that water quality deteriorated in the affected regions. These outcomes are consistent with the loss of the scavenging function of the vultures.