Numerous species of mammals, reptiles, and birds have disappeared from Earth, and humans are responsible for the extinction of megafauna.
When we talk about mass extinction, we often imagine a chaotic and apocalyptic situation. However, it can happen gradually and almost imperceptibly. This is precisely what human activity is doing and has done to various plant and animal species. For example, humans have been responsible for the “extinction” of megafauna, which are giant mammals.
This was concluded by scientists at the University of Aarhus who reviewed and compiled articles on this topic and published their findings in the scientific journal Cambridge Prisms: Extinction.
In the last 50,000 years, numerous species of mammals, reptiles, and birds have disappeared from Earth, especially the large ones. Animals weighing 45 kilograms up to herbivores of a ton or more are considered “large,” and these animals were the most affected by extinction.
During this period, at least 161 megafauna mammal species went extinct, with 46 of them being megaherbivores. Of the 57 species that were alive during all this time, only 11 remain alive, but at risk of extinction.
Humans and the extinction of megafauna
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The study involved various fields of science, focusing on direct studies regarding the extinction of large animals. The researchers included analyses of the time of “extinction,” dietary preferences, climate and habitat requirements, genetic estimates of population sizes, and evidence of hunting by humans.
Furthermore, a variety of studies were extremely important for the researchers to know what to consider and what to discard. They ruled out the prominence of climate change, even the effects caused by the extreme cooling of glacial and interglacial periods. This is because, although animals and plants were affected worldwide, only the extinction of large animals, especially the largest ones, was identified. Previous interglacial periods and ice ages did not have this effect.
Another point is that recent extinctions of megafauna occurred in both stable and unstable climate locations. This showed that temperature change is not the main factor.
Regarding archaeological evidence, researchers found evidence of traps set by humans to capture large animals. They also conducted isotope analyses showing traces of protein on spearheads from large mammals, indicating that humans did have a connection to the extinction of megafauna.
Role
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In the case of primitive humans, they were skilled hunters able to reduce animal populations. Since the larger animals were more vulnerable and had longer gestation periods with few offspring, excessive hunting of them was easy for our ancestors.
This extinction of megafauna occurred at different times, happening quickly in certain places and taking up to 10,000 years to occur in others. However, extinction occurred in all places after humans arrived. In Africa, this happened after cultural and technological advances of our species. The extinction of megafauna can be seen with species disappearing on all continents except Antarctica.
Among the animals that were part of megafauna were mammoths, mastodons, and giant sloths, and their loss had significant ecological consequences, as pointed out by researchers. These species influenced vegetation structure and balanced dense forest areas with open spaces, dispersed seeds, and cycled nutrients.
After these large mammals went extinct, changes occurred in ecosystem structure and functions. This underscores the importance of conserving and restoring environments and, if possible, reintroducing megafauna to them.
Source: Canaltech
Images: Canaltech
