From 50,000 years to 6,000 years ago, many of the world’s largest animals, including such iconic grassland grazers as the woolly mammoth, giant bison, and ancient horses, went extinct.
From 50,000 years to 6,000 years ago, many of the world’s largest animals, including such iconic grassland grazers as the woolly mammoth, giant bison, and ancient horses, went extinct. The loss of these grazing species triggered a dramatic increase in fire activity in the world’s grasslands, according to a new Yale-led study published Nov. 26 in the journal Science.
In collaboration with the Utah Natural History Museum, Yale scientists compiled lists of extinct large mammals and their approximate dates of extinctions across four continents. The data showed that South America lost the most grazers (83% of all species), followed by North America (68%). These losses were significantly higher than in Australia (44%) and Africa (22%).
They then compared these findings with records of fire activity as revealed in lake sediments. Using charcoal records from 410 global sites, which provided a historical record of regional fire activity across continents, they found that fire activity increased after the megagrazer extinctions. Continents that lost more grazers (South America, then North America) saw larger increases in fire extent, whereas continents that saw lower rates of extinction (Australia and Africa) saw little change in grassland fire activity.
Read more at: Yale University
The Age of Mammals, a mural by Rudolph F. Zallinger. (Photo Credit: © 2016 Peabody Museum of Natural History, Yale University)
