Prehistoric wild boars had a plant-based diet

Research by zooarchaeologist Nathalie Brusgaard of the University of Groningen’s Faculty of Arts has revealed that prehistoric wild boars primarily ate plants. She is the first person in the Netherlands to have identified the diet of the wild boar by examining the chemical composition of its bones. The results of her research may help to determine more accurately the moment when humans switched from hunting to animal husbandry. Brusgaard’s findings were published today in the scientific journal PLOS ONE .

Around 5450 BC, people lived a nomadic lifestyle in small groups. Some of these groups spent the winter in what is now the Alblasserwaard, a region of Netherlands located in the provinces of Zuid-Holland and Utrecht. Those who settled there were part of the Swifterbant culture, which covered a large part of the Netherlands and extended into parts of Germany and Belgium. Numerous sites of this culture, rich in artefacts, have been uncovered in the Netherlands, including near Hardinxveld-Giessendam, where a great deal of archaeological research has already been carried out.

Studying the wild boar

But while many studies focus on prehistoric people, Brusgaard set her sights on the prehistoric wild boar that roamed the earth at the time when humans switched from hunting and gathering to animal husbandry. ‘That transition was a complex and lengthy process lasting perhaps 1,000 to 1,500 years – although that duration is still debated among archaeologists,’ Brusgaard says.

How big were wild boars?

Changing hunting habits

Around 5000 BC, humans gradually started to change their habit of moving around from place to place; they stayed in the same area for several seasons. Their hunting habits also changed. ‘They stopped hunting adult animals that mainly lived alone and started hunting younger animals that lived in groups,’ says Brusgaard. This shift in behaviour may reflect human changes: perhaps the young animals were easy prey, or there was a need for more meat. ‘But it is equally possible that it was the wild boar that changed their behaviour, for example, in response to the presence of humans or a change in the environment. Perhaps this forced humans to change the way they hunted.’  

Swimming from island to island

The area where wild boar lived some 7,000 years ago was quite large. Brusgaard: ‘They had a fairly large habitat in what is now known as the Alblasserwaard. It was an area with a lot of water and river dunes, which are little islands formed by sand deposits. They could swim and probably moved from island to island.’

A plant-based diet

What does the diet tell us?

Brusgaard believes that determining the diet of wild boar is an important basis for subsequent research. ‘The next step is to examine pig bones from a slightly later period using the same chemical technique to determine the diet of these pigs and to compare it with that of the wild boar. We know that domestic pigs in the prehistoric era often ate humans’ food waste, which also contained meat or fish. So, their diet differed from that of the wild boar.’ Brusgaard hopes that her new research will enable her to more accurately determine the moment at which humans started keeping animals. ‘This ultimately led to people staying in the same place. This transition marks a change in the way people lived.’

About the research

Brusgaard’s research is part of the project ‘ The Emergence of Domesticated Animals in the Netherlands’ (EDAN), on the domestication process of pigs and cattle, at the Groningen Institute for Archaeology.