The first inhabitants of the Americas may have crossed two continents by hunting giants

A new study has shown that early human groups in different parts of the Americas specialised in hunting large animals — mammoths, gomphotheres, giant ground sloths and other large herbivores. These animals provided plenty of meat and fat, occupied vast territories and may have served as a kind of ‘survival strategy’ for ancient hunters in these new lands.

The study has been published in *Science Advances*.

The authors analysed data from 50 archaeological sites across the Americas — from Beringia and North America to South America. They concluded that for three early groups — the Eastern Beringians, the Clovis culture and the users of South American Fishtail-type arrowheads — the largest animals may have accounted for the bulk of their dietary biomass.

What the scientists found

Archaeologists have long debated how the first humans were able to spread so rapidly across two continents. One theory suggests that they were versatile hunters and gatherers, meaning they utilised whatever food was available – small animals, fish, plants, birds and local resources. Another theory suggests that early groups relied on megafauna — the largest animals in the landscape.

New research supports the second theory. According to the authors’ calculations, 83–88 per cent of the dietary biomass of the early groups studied came from large herbivores: mammoths, gomphotheres and giant ground sloths.

Put simply, if we consider not just the number of bones but how much food each animal provided, the giants of the Ice Age dominated the diet by a wide margin.

Why is this surprising?

Mammoths and giant sloths were not the most numerous animals in the landscape. Small mammals — such as hares or rodents — would have been far more common.

But the archaeological record tells a different story: rare large animals left a far more noticeable mark than small prey. According to Ben Potter of the University of Alaska in Fairbanks, if early humans had been omnivorous, the most common animals would have been found more frequently at the sites. Instead, mammoths and ground sloths dominate the record, whilst hares and mice are almost absent.

This does not mean that people did not eat anything else at all. But the research suggests that the largest animals may have been the main source of calories and fat.

How hunting helped them cross two continents

When people find themselves in unfamiliar territory, they usually need time to understand the new landscape: where to find water, which plants are edible, which animals are best to hunt, and where they appear in different seasons.

But large animals change this dynamic. Mammoths and other giants occupied vast territories and behaved in a relatively predictable manner. If hunters already knew how to track such prey, it was easier for them to move on — without having to learn each new ecosystem from scratch.

Study co-author Mat Wooller explains it this way: specialised hunters could use their knowledge of megafauna, such as mammoths, to successfully expand across continents, rather than having to relearn about local plants and small game each time.

This is precisely why the headline ‘Hunting giants helped them cross two continents’ works: it is not that mammoths literally ‘led’ people, but that large prey could have provided them with a clear and repeatable survival strategy.

The study also explains why early toolkits in different parts of the Americas look similar. If people hunted large animals across different landscapes, they did not need to radically alter their technologies for each specific area.

Large arrowheads associated with the hunting of large game, as well as specialised tools for butchering carcasses, are found at these sites. At the same time, fishing gear and tools for processing plants are conspicuously absent from these early assemblages.

What this tells us about the extinction of mammoths

The study touches on another major debate: why the Ice Age megafauna disappeared from the Americas.

The authors note that the disappearance of large animals proceeded in waves from north to south. In Alaska, mammoths and horses disappeared around 13,300 years ago, in North America, the Clovis-era megafauna disappeared around 12,800 years ago, whilst in South America, gomphotheres and giant ground sloths persisted until around 11,600 years ago.

This coincides with the spread of humans across the continents. The authors therefore believe that hunting may have been a significant factor in the extinction of these giants. However, they do not attribute everything to a single explanation: climate change may also have reduced the animals’ habitats and made them more vulnerable.

Why the giants were vulnerable

Large herbivores reproduce slowly. They have long intervals between births, few offspring, and adult individuals usually have almost no natural predators.

This made them particularly vulnerable to a new type of predator — humans with effective weapons and organised hunting methods. According to Potter, such animals lacked ‘learned caution’ in the face of technologically advanced hunter-gatherers.

Even relatively low hunting pressure could become a serious problem if populations were already experiencing climatic stress.

Background

The settlement of the Americas remains one of the most hotly debated topics in archaeology. Scholars disagree on migration routes, the timing of the arrival of the first humans, the role of the Clovis culture, and how early groups adapted to new landscapes.

This new study does not resolve all these questions, but it does offer an important insight: early humans may have been able to move across different natural zones because their primary prey was not local small game, but large animals found across vast expanses.

In other words, hunting these giants may not simply have been a means of obtaining food. It may have been a strategy for settlement.

Source

Study: Ben Potter et al., “Hemisphere-wide evidence of Early Paleoindian megaherbivore specialisation”, Science Advances, 2026.