Keystone species keep ecosystems from collapsing. Killing them is bad.

"#Vultures act as nature’s sanitation service. In India, their diet consisted largely of rotting livestock carcasses—numbering 30m a year. A group of vultures can polish off a cow’s carrion in 40 minutes. Their strongly acidic digestive tracts destroy most germs.

Historically, vultures were widespread in India. But between the 1990s & early 2000s their numbers plummeted by more than 90%, from around 40m. The cause was diclofenac, an anti-inflammatory drug that farmers began using to treat their cattle. Though the drug was harmless to both cows & humans, birds that consumed animals treated with diclofenac suffered from kidney failure & died within weeks.

Without vultures, carcasses attracted feral dogs & rats. Not only do these animals carry rabies & other diseases that threaten humans, they are far less efficient at finishing off carrion. The rotting remains were full of pathogens that spread to drinking water." https://www.economist.com/graphic-detail/2023/08/22/the-sudden-demise-of-indian-vultures-killed-thousands-of-people