How many animal species have humans driven to extinction?

Humans are very good at wiping out wildlife. From dodos, to golden toads, to Tasmanian tigers, many species have succumbed to our unique blend of destruction. But just how many animal species have humans driven to extinction?

Scientists don't have an exact answer to this question, and it's a tricky number to estimate. However, it could be hundreds of thousands.

Let's start with the confirmed extinctions. A total of 777 animals have gone extinct since the beginning of the modern era in 1500, according to the International Union for Conservation of Nature (IUCN) Red List. Some of those extinctions could have been natural, but humans will have had a hand in almost — if not all — of them given how much we've impacted nature, particularly over the last 500 years. Humans began contributing to extinctions thousands of years ago, long before 1500, but scientists weren't around to study those extinctions and there's enough uncertainty surrounding today's extinction rate, so we'll focus on roughly the past 500 years. 

The IUCN has assessed the extinction risk of only about 5% of the world's known species, so there must be many more extinctions that have not been recorded. A 2022 study published in the journal Biological Reviews suggested that as many as 150,000 to 260,000 of all known species could have perished since roughly 1500. 

The numbers were so large, they surprised the study's lead author, Robert Cowie, a research professor at the University of Hawaii. "I thought, jeez, have I made some mistakes in the calculations?" Cowie told Live Science. 

Related: What's the first species humans drove to extinction?

Cowie hadn't made a mistake, but his estimates came with significant caveats. To calculate the figure, his team took a random sample of 200 land snails and, using previous scientific studies and expert consultation, determined how many of the snails had gone extinct. Then, they calculated how many species would have gone extinct if all known species had suffered a similar extinction rate consistently over 500 years.