Early Americans Relied Primarily on Megafauna Across the Americas, Study Finds
Analysis of 50 archaeological sites shows that the first Native American groups obtained most of their calories from large herbivores such as mammoths and ground sloths, supporting a model of dietary specialization rather than generalist foraging.
A study of 50 sites spanning Alaska to South America indicates that the continent's earliest inhabitants derived the majority of their food from large herbivores. Researchers examined animal bones from campsites associated with Eastern Beringians, Clovis people and Fishtail Projectile Point groups, finding that 83% to 88% of the edible biomass came from megaherbivores such as mammoths, gomphotheres and giant ground sloths.
The team, led by University of Alaska Fairbanks anthropology professor Ben Potter and McMaster University researcher James Chatters, compared the archaeological record with estimates of natural animal abundance. Even when models were adjusted to inflate the presence of small animals, megaherbivores remained the dominant source of food.
"One of two competing ideas is dietary generalization: exploiting a wide variety of resources that would differ based on region," Potter said.
"The test of dietary specialization isn't just how many of a given animal you find at an ancient campsite. It's what the record looks like relative to natural abundance. If early people were dietary generalists, you'd expect to find the most common animals would be more common in peoples' campsites," he added.
"Animals like mammoths and ground sloths, which were actually quite rare in the landscape, completely dominate the archaeological record. Rabbits and mice, which would have been everywhere, barely register," Potter explained.
The prevalence of large-game hunting is reflected in the similarity of stone tools across widely separated regions, with fluted projectile points and butchering implements common, while fishing gear and plant-processing tools are largely absent. Co-author Mat Wooller noted that megafauna such as mammoths occupied extensive ranges, allowing specialist hunters to expand rapidly without needing to adapt to local small-game ecosystems.
The research also links the timing of megafauna extinctions to human arrival, showing a southward wave of disappearance that mirrors the spread of people. Mammoths and horses vanished in Alaska around 13,300 years ago, North American megafauna were gone by 12,800 years ago, and South American species persisted until about 11,600 years ago. The authors suggest that slow-reproducing, predator-free megaherbivores were especially vulnerable to sustained hunting pressure, compounded by climate-driven habitat loss.
