The extinction of the great prehistoric herbivores sparked fires around the world

Between 50,000 and 6,000 years ago, the extinction of large animals such as the mammoth, the giant bison or the ancient horses not only had consequences for predators, but also for the prairies, where grass, leaves and wood began to accumulate. start fires all over the planet.

This is the main conclusion of an investigation led by the Yale university (Connecticut) with the collaboration of Utah Museum of Natural History, which was published this Thursday in the magazine Science.

To carry out the study, the researchers collected data on the disappearance of these large species on four continents: South America lost 83% of all species, North America 68%, Australia 44% and Africa, the 22%.

They then compared these results with records of fire activity revealed in sediments from 410 locations around the world.

By analyzing these charcoal sediments, they obtained a historical record of regional fire activity on all continents and found that fire activity increased after the extinction of the fires. megaherbivores.

The study concludes that in the continents that lost the most herbivores (South America and later North America) there was a greater increase in the extent of fires, while in the continents with lower extinction rates (Australia and Africa) there was hardly any change in grassland fire activity.

And, although in that same period, many ancient species – such as mastodons, diprotodons or giant sloths that fed on shrubs and trees in wooded areas – also became extinct, their disappearance had “Less impact” in forest fires, the study points out.

Following the loss of grassland ecosystems around the world, the new ‘herders’, including livestock, eventually adapted to the new ecosystems.

For Allison Karp, researcher of Yale and co-author of the work, the study showed that these extinctions had consequences, so “Studying its effects will help to understand how herbivores shape global ecology today “.

Scientists should consider the role of grazing cattle and wild herders in mitigating fires and climate change, the authors warn.

”This work highlights the importance that shepherds can have in determining fire activity. We must pay close attention to these interactions if we want to accurately predict the future of fires. “, concludes the main author of the article, Carla Staver.