NAIROBI, Kenya (AP) — Poachers killed an estimated 100,000 elephants across Africa between 2010 and 2012, a huge spike in the continent’s death rate of the world’s largest mammals because of an increased demand for ivory in China and other Asian nations, a new study published Monday found.

Warnings about massive elephant slaughters have been ringing for years, but Monday’s study is the first to scientifically quantify the number of deaths across the continent by measuring deaths in one closely monitored park in Kenya and using other published data to extrapolate fatality tolls across the continent.