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Did humans cause the Quaternary megafauna extinction?

10,000 to 50,000 years ago, hundreds of the largest mammals went extinct. It's likely that humans were the key driver of this.

By: Hannah Ritchie
November 30, 2022
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Update note

This article was first published in 2022. It was updated in 2025 to update references, add a clearer section on data sources and evidence, and clarify differences in extinction rates of genera versus species.

Humans have had such a profound impact on the planet’s ecosystems and climate that Earth might be defined by a new geological epoch: the Anthropocene (where “anthropo” means “human”).

Some think this new epoch should start during the Industrial Revolution, and some at the advent of agriculture 10,000 to 15,000 years ago. This feeds into the popular notion that environmental destruction is a recent phenomenon.

The lives of our ancestors are often romanticized. Many think they lived in balance with nature, unlike modern society where we fight against it. But when we look at the evidence of human impacts over millennia, it's hard to see how this was true.

Our ancient ancestors contributed to the extinction of many of the world's largest mammals ('megafauna'). This was during an event known as the Quaternary megafauna extinction (QME).

The extent of these extinctions across continents is shown in the chart.

Between 52,000 and 9,000 BCE, more than 178 species of the world’s largest mammals were killed off. These were mammals heavier than 44 kilograms, ranging from mammals the size of sheep to mammoths.

There is strong evidence to suggest that these were largely driven by humans — we look at this in more detail later.

Africa was the least hard-hit, losing only 21% of its megafauna. Humans evolved in Africa, and hominins had already interacted with mammals for a long time. The same is also likely to be true across Eurasia, where 35% of megafauna were lost. But Australia, North America, and South America were particularly hard-hit; very soon after humans arrived, most large mammals were gone. Australia lost 88%; North America lost 72%; and South America, 83% of large mammal genera.1

Far from being in balance with ecosystems, tiny populations of hunter-gatherers changed them forever. By 8,000 BCE — almost at the end of the QME — there were only around 5 million people in the world.

The image is a data visualization detailing the megafauna losses during the Quaternary extinction event, which occurred between 52,000 years and 9,000 years ago. The title at the top states "Megafauna losses at the Quaternary Extinction" and explains that this event resulted in the extinction of over 100 species of large mammals, with humans thought to be a significant factor. The chart uses blue bars to represent the number of megafauna survivors and red bars to show the extinct species across different regions: - **Africa**: 38 survivors, 10 extinct. - **Eurasia**: 17 survivors, 9 extinct. - **South America**: 10 survivors from 60, and 50 extinct. - **North America**: 13 survivors, 34 extinct. - **Australia**: 2 survivors, 14 extinct. Each section includes additional context about human arrival and extinctions in that region. For instance, in Australia, it notes that 88% of genera went extinct. The footer provides sources for the data: Barnosky (2008), PNAS, and Kock and Barnosky (2006), along with the statement "Our World in Data" which indicates the research context. The image is licensed under CC-BY by the author Hannah Ritchie.

Did humans cause the Quaternary megafauna extinction?

The driver of the QME has been debated for centuries. Climate and human impacts have been proposed as potential drivers.

One possibility is that both played some role in the downfall of the mammals. This could be through overhunting, the reshaping of landscapes through fire, or the introduction of invasive species.

There are several reasons why we think our ancestors were at least partly responsible.

Extinction timings closely match the timing of human arrival. The timing of megafauna extinctions was not consistent across the world; instead, the timing of their demise coincided closely with the arrival of humans on each continent. The timing of human arrivals and extinction events is shown on the map below.

Humans reached Australia somewhere between 65 to 44,000 years ago.2 Between 50 and 40,000 years ago, 82% of megafauna had been wiped out. It was tens of thousands of years before the extinctions in North and South America occurred. And several more before these occurred in Madagascar and the Caribbean islands. Elephant birds in Madagascar were still present eight millennia after the mammoth and mastodon were killed off in America. Extinction events followed in man’s footsteps.

QME selectively impacted large mammals. There have been many extinction events in Earth’s history. There have been five big mass extinction events and several smaller ones. These events don’t usually target specific groups of animals. Large ecological changes tend to impact everything from large to small mammals, reptiles, birds, and fish. During times of high climate variability over the past 66 million years (the ‘Cenozoic period’), neither small nor large mammals were more vulnerable to extinction.3

The QME was different and unique in the fossil record: it selectively killed off large mammals. Now there are obvious reasons why larger mammals are at a greater risk of extinction from any cause: they are slower to reproduce, so declines or crashes in their populations take longer to recover from.

But there is also a strong bias to human pressures: humans selectively hunt the larger ones.

Islands were more heavily impacted than Africa. As we saw previously, Africa was less heavily impacted than other continents during this period. We might expect this since hominids had been interacting with mammals for a long time before this. These interactions between species would have impacted mammal populations more gradually and to a lesser extent. They may have already reached some form of equilibrium. When humans arrived on other continents – such as Australia or the Americas – these interactions were new and represented a step-change in the dynamics of the ecosystem. Humans were efficient new predators.

There have now been many studies focused on the question of whether humans were a key driver of the QME. Many suggest that the answer is yes. Climatic changes might have driven an initial decline in large mammal populations — small population crashes — but human pressures are likely to have thwarted their recovery. Large mammals survived previous periods of climatic change, but the arrival of humans put pressure on already-depleted populations.

Human impact on ecosystems dates back tens of thousands of years, despite the Anthropocene paradigm implying this is a recent phenomenon. We’ve not only been in direct competition with other mammals, but we’ve also reshaped the landscape beyond recognition.

A world map illustrating human migration and the extinction of large mammals from 52,000 to 9,000 BC. Various regions are marked with key information regarding human arrival and extinction rates of large mammals. - **Europe**: Human arrival occurred 35,000 to 45,000 years ago, with 35% of large mammal species going extinct between 23,000 to 48,000 years ago. - **Arabian Peninsula**: Multiple waves of human migration began 50,000 to over 100,000 years ago. - **Africa**: Home to hominids that evolved alongside large mammals, with 21% extinction. - **Madagascar**: Human arrival occurred 4,000 to 10,000 years ago. - **Indo-Malaya**: Humans arrived 44,000 to 73,000 years ago. - **Japan**: Human arrival happened 20,000 to 24,000 years ago. - **North America**: Human migration occurred 12,000 to 20,000 years ago, with 72% of large mammal species going extinct. - **South America**: Human arrival was between 8,000 to 16,000 years ago, with 83% extinction. - **Australia**: Human presence began 40,000 to 60,000 years ago, leading to an 88% extinction rate. - **New Zealand**: Humans arrived 1,000 to 2,500 years ago. Data sources listed: Koch and Barnosky (2006), Barnosky (2008), Andermann et al. (2020)

Data sources and evidence

The main figures used in the chart and map above are sourced from Barnosky (2008) and Andermann (2020). Here I’ll document these figures more clearly, and provide some supporting literature and evidence.

Number and share of mammal genera that went extinct

This data comes from Barnosky (2008), with Koch and Barnosky (2006) being the underlying data source.

As Barnosky (2008) states:

“Extinction intensity varied by continent, with Australia, South America, and North America hard-hit, losing 88% (14 extinct, 2 surviving), 83% (48 globally extinct, 2 extinct on the continent, 10 surviving), and 72% (28 globally extinct, 6 extinct on the continent, 13 surviving), respectively, of their megafauna mammal genera. Eurasia lost only 35% of its genera (4 globally extinct, 5 extinct on the continent, 17 surviving). Africa was little affected, with only 21% loss (7 globally extinct, 3 extinct on the continent, 38 surviving), including at least three Holocene extinctions.”

These figures can also be found in Table 2 of Koch and Barnosky (2006) which I’ve copied below.

Number globally extinct genera

Number extinct genera surviving on other continents

Number Holocene survivors

% extinct

Africa

7

3

38

21

Australia

14

—

2

88

Eurasia

4

5

17

35

North America

28

6

13

72

South America

48

2

10

83

Specific mammal extinctions (included in the map)

  • Ground sloth: Using radiocarbon dating, Steadman et al. (2005) reported that the “last” appearance of ground sloths in South America was likely 11,000 years ago and 10,500 years ago in North America.4 They were, however, present on the West Indian Islands until around 4,500 years ago. The authors also note that “the chronology of last appearance of extinct sloths, whether on continents or islands, more closely tracks the first arrival of people.”
  • American mastodon: Zazula et al. (2014) report that the American mastodon went extinct 10,000 to 11,000 years ago. Prior to that, its geographical range shrunk substantially.5 There is much more mixed evidence on whether the main driver of its extinction was climate change or human pressures. The paper above strongly infers that climate change played a bigger role. And other research suggests that mastodon migrations due to climatic changes reduced their genetic diversity and made them more vulnerable to extinction.6
  • European lion: The European cave lion (Panthera spelaea) is thought to have gone extinct around 14,000 years ago. There is some suggestion that it survived in very localised populations for several thousand more years.7 Climate change is thought to have played some role in its contraction of range — in particular, a change in habitat — but there is also clear evidence of human hunting and pressures, which might have been a tipping point into extinction.8
  • Giant kangaroo: Arman et al. (2025) report that several species of giant kangaroo went extinct during the wave of Quaternary extinctions in Australia.9 They note that “Thus, their demise was likely not driven by climate change, leaving humans as the probable cause.”.

Timing of extinction events

The exact timing of the Quaternary extinction events in different is uncertain, and it’s thought that these extinctions could happen in multiple “wave” events. In the map above I’ve mostly used estimates from Barnosky (2008), with exact quotes below. Most other literature is broadly in line with these dates, but the exact start and end dates can vary.

  • North America: “In central North America, extinctions corresponded with the second Eurasia–Beringia pulse, starting at 15.6 kyr B.P. and concentrating between 13.5 and 11.5 kyr B.P.” (Barnosky, 2008)
  • South America: “In South America, the extinction chronology is not well worked out, but growing evidence points to a slightly younger extinction episode, between 12 and 8 kyr B.P.” (Barnosky, 2008)
  • Australia: “Beginning by 50 kyr B.P. in Australia and largely ending there by 32 kyr B.P., possibly concentrated in an interval between 50 and 40 kyr B.P.”
  • Eurasia: “In northern Eurasia and Beringia, extinctions were later and occurred in two pulses, the first between 48 and 23 kyr B.P. and the second mainly between 14 and 10 kyr B.P., although some species lingered later in isolated regions (Irish elk until 7 kyr B.P. in central Siberia and mammoths until 3 kyr B.P. on Wrangel and St. Paul Island)”

Timing of human arrival

The exact timing of human arrival on different continents is still debated, with new genetic or archaeological evidence narrowing or extending the potential timelines.

In the table below, I provide a list of estimates — measured as modern human arrival, in thousands of years ago — from various sources. All have significant uncertainty, which is why they are given as a range in the map above.

Region / country

Andermann et al. (2020)

Barnosky (2008)

Koch and Barnosky (2006)

Additional sources

Australia

44,000 - 65,000

“≈50 kyr B.P.”

44,000 - 72,000

65,000 (Clarkson et al. 2017)10

Europe / Eurasia

40,000 - 48,000

“≈40,000”

24,000 - 50,000

Arabian Peninsula

Estimates from 50,000 to over 100,000 years depending on extent of settlement (Groucutt et al. 2018)11

Indo-Malaya

44,000 - 73,000

Japan

20,000 - 24,000

North America

12,000 - 20,000

11,500 - 13,500

South America

8,000 - 16,000

“Near 14.6 kyr B.P.”

11,500 - 18,000

Madagascar

4,000 - 10,000

New Zealand

736 - 2,216

Endnotes

  1. Barnosky, A. D. (2008). Megafauna biomass tradeoff as a driver of Quaternary and future extinctions. Proceedings of the National Academy of Sciences, 105.

    Koch, P. L., & Barnosky, A. D. (2006). Late Quaternary extinctions: state of the debate. Annu. Rev. Ecol. Evol. Syst., 37(1), 215-250.

  2. Andermann, T., Faurby, S., Turvey, S. T., Antonelli, A., & Silvestro, D. (2020). The past and future human impact on mammalian diversity. Science Advances, 6(36), eabb2313.

    Smith, F. A., Smith, R. E. E., Lyons, S. K., & Payne, J. L. (2018). Body size downgrading of mammals over the late Quaternary. Science, 360(6386), 310-313.

  3. Smith, F. A., Smith, R. E. E., Lyons, S. K., & Payne, J. L. (2018). Body size downgrading of mammals over the late Quaternary. Science, 360(6386), 310-313.

  4. Steadman, D. W., Martin, P. S., MacPhee, R. D., Jull, A. T., McDonald, H. G., Woods, C. A., ... & Hodgins, G. W. (2005). Asynchronous extinction of late Quaternary sloths on continents and islands. Proceedings of the National Academy of Sciences, 102(33), 11763-11768. Mason (2005). Humans Drove Giant Sloths to Extinction. Science.

  5. Zazula, G. D., MacPhee, R. D., Metcalfe, J. Z., Reyes, A. V., Brock, F., Druckenmiller, P. S., ... & Southon, J. R. (2014). American mastodon extirpation in the Arctic and Subarctic predates human colonization and terminal Pleistocene climate change. Proceedings of the National Academy of Sciences, 111(52)

  6. Karpinski, E., Hackenberger, D., Zazula, G., Widga, C., Duggan, A. T., Golding, G. B., ... & Poinar, H. N. (2020). American mastodon mitochondrial genomes suggest multiple dispersal events in response to Pleistocene climate oscillations. Nature communications, 11(1), 4048.

  7. Stuart and Lister (2011). Extinction chronology of the cave lion Panthera spelaea. Quaternary Science Reviews.

  8. Cueto, M., Camaros, E., Castanos, P., Ontanon, R., & Arias, P. (2016). Under the skin of a lion: unique evidence of Upper Paleolithic exploitation and use of cave lion (Panthera spelaea) from the Lower Gallery of La Garma (Spain). PLoS One, 11(10), e0163591.

  9. Arman, S. D., Gully, G. A., & Prideaux, G. J. (2025). Dietary breadth in kangaroos facilitated resilience to Quaternary climatic variations. Science, 387(6730), 167-171.

  10. Clarkson, C., Jacobs, Z., Marwick, B., Fullagar, R., Wallis, L., Smith, M., ... & Pardoe, C. (2017). Human occupation of northern Australia by 65,000 years ago. Nature, 547(7663), 306-310.

  11. Groucutt, H. S., Grün, R., Zalmout, I. A., Drake, N. A., Armitage, S. J., Candy, I., ... & Petraglia, M. D. (2018). Homo sapiens in Arabia by 85,000 years ago. Nature ecology & evolution, 2(5), 800-809.

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Our articles and data visualizations rely on work from many different people and organizations. When citing this article, please also cite the underlying data sources. This article can be cited as:

Hannah Ritchie (2022) - “Did humans cause the Quaternary megafauna extinction?” Published online at OurWorldinData.org. Retrieved from: 'https://ourworldindata.org/quaternary-megafauna-extinction' [Online Resource]

BibTeX citation

@article{owid-quaternary-megafauna-extinction,
    author = {Hannah Ritchie},
    title = {Did humans cause the Quaternary megafauna extinction?},
    journal = {Our World in Data},
    year = {2022},
    note = {https://ourworldindata.org/quaternary-megafauna-extinction}
}
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