It is estimated that, since 1970, Earth’s various populations of wild land animals have lost, on average, 60 percent of their members. Zeroing in on the category we most relate to, mammals, scientists believe that for every six wild creatures that once ate and burrowed and raised young, only one remains. What we have instead is ourselves. A study published this year in the Proceedings of the National Academy of Sciences found that if you look at the world’s mammals by weight, 96 percent of that biomass is humans and livestock; just 4 percent is wild animals.

It is estimated that, since 1970, Earth’s various populations of wild land animals have lost, on average, 60 percent of their members. Zeroing in on the category we most relate to, mammals, scientists believe that for every six wild creatures that once ate and burrowed and raised young, only one remains. What we have instead is ourselves. A study published this year in the Proceedings of the National Academy of Sciences found that if you look at the world’s mammals by weight, 96 percent of that biomass is humans and livestock; just 4 percent is wild animals.