Why did South America lose most of its megafauna?

During the Late Pleistocene to the beginning of the Holocene, South America experienced a severe extinction event that wiped out a vast majority of its large animal species. Across the globe, this period saw a dramatic loss of megafauna weighing 45 kilograms or more, with South America suffering an 83 percent extinction rate among these large animals. Scholars generally debate whether these losses were driven primarily by globally expanding human populations through hunting and environmental alteration, by natural climatic shifts, or by a combination of both factors.

What we know

• South America lost 83 percent of its megafaunal species during the Late Pleistocene to early Holocene extinction event. [2]
• The Late Pleistocene extinctions are differentiated by an extreme size bias toward large animals while small animals were largely unaffected. [2]
• Major extinctions in the Americas occurred about 13,000 years ago, spanning a maximum of 3,000 years. [2]
• Most scholars support at least a contributory role of humans in the extinctions, driven by hunting or environmental alteration, alongside climatic factors. [1, 2] · medium confidence

Still open

• The relative importance of human impacts versus climatic factors in driving the Late Pleistocene megafauna extinctions remains a subject of long-running controversy.

Where to go next

• what caused itHow did human hunting impact ancient megafauna?
• what followedWhat caused the collapse in faunal density?
• how we knowHow do scientists date the end of the Pleistocene?
• the bigger pictureWhat is the broader Quaternary extinction event?
• compared withHow severe were the extinctions in North America?
• an unexpected connectionHow does the Ice Age extinction connect to modern ecological collapse?The Late Pleistocene megafauna extinctions are often viewed as part of a single continuous Quaternary extinction event that extends directly into modern human-driven ecological crises.

Sources

• [1]Quaternary extinction event (Wikidata Q1759232) · CC0 1.0
• [2]Late Pleistocene extinctions · CC BY-SA 4.0
• [3]Holocene extinction · CC BY-SA 4.0
• [4]Cretaceous–Paleogene extinction event · CC BY-SA 4.0
• [5]Permian–Triassic extinction event · CC BY-SA 4.0