A research project spanning more than three decades showed that free-ranging Bison provided significant benefits to tall grass prairies, including greater plant diversity and resilience to drought. From lead researcher, Zak Ratajczak: “Bison were an integral part of North American grasslands before they were abruptly removed from over 99% of the Great Plains. Our results suggest that many grasslands in the central Great Plains have substantially lower plant biodiversity than would have occurred before bison were widely wiped out,” Ratajczak said. “Returning or ‘rewilding’ native megafauna could help to restore grassland biodiversity.”