Loss of ancient grazers triggered a global rise in fires

The Age of Mammals, a mural by Rudolph F. Zallinger. Peabody Museum of Natural History, Yale University) - 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. 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.