Tyler Smith
Nearly five hundred vertebrate species have gone extinct over the last 100 years, a rate that outpaced the last five mass extinction events on planet earth. Some of these species, known as keystone species, help to hold entire ecosystems together.
In a paper in the American Economic Review, authors Eyal Frank and Anant Sudarshan studied the sudden collapse of vulture populations across the Indian subcontinent as a result of farmers’ unintentionally poisoning the birds by using the painkiller diclofenac on their cattle. They found that when vultures in India died out, human mortality increased significantly.
The researchers argue that when vultures disappeared and were no longer scavenging dead livestock, carrion were more likely to be either dumped in rivers, leading to deadly water pollution, or eaten by other scavengers, such as feral dogs and rats, that are more prone to transmitting diseases to humans.
Using a differences-in-differences approach, they compared changes in human mortality in areas that were highly suitable habitats for vultures to areas that were less suitable around the time the vulture populations disappeared.
Πηγή: www.aeaweb.org