On a global scale, livestock outweighs wildlife—literally

If you weigh all of the animals in the world, you’ll find that livestock vastly surpasses the biomass of all of the warm-blooded wild animals. Researchers recently found livestock biomass has reached about 630 million tons. That is 30 times the biomass of wild terrestrial mammals and 15 times that of wild marine mammals. “This study is an attempt to see the bigger picture,” said Ron Milo, head of the Mary and Tom Beck Canadian Center for Alternative Energy Research, in a press release. “The dazzling diversity of various mammal species may obscure the dramatic changes affecting our planet. But the global distribution of biomass reveals quantifiable evidence of a reality that can be difficult to grasp otherwise: It lays bare the dominance of humanity and its livestock over the far smaller populations of remaining wild mammals.” To conduct the research, Milo and his colleagues collected existing data on wild mammal species. For ones that didn’t have accessible data, they used machine learning to determine body weight. Among wildlife, they found that species like white-tailed deer (Odocoileus virginianus) and wild boar (Sus scrofa) ranked high on the biomass chart, due in part to human activity.

Read more in Proceedings of the National Academy of Sciences.