Ancient Foxes Relied On Human Leftover Foods for 42 Millennia

Researchers have found that ancient foxes have relied on people's leftover foods for at least 42 millennia, their diets being influenced by the game hunted by ancient humans. Their study's conclusions mean that these small and ancient carnivores could be used as tracers of ancient human activity.

These findings by Universität Tübingen, Germany professor Chris Baumann and his co-authors Hervé Bocherens, Dorothée Drucker, and Nicholas Conard were published in a paper entitled, "Fox dietary ecology as a tracer of human impact on Pleistocene ecosystems" last July 22, 2020, in PLOS ONE, an open-access journal.

Foxes enjoy eating leftovers. Foxes in the wild are known to feed regularly on the scraps left by wolves, bears, and other larger predators. However, as foxes start to live closer to humans and human civilization, their diet becomes more and more composed of the leftover foods that humans regularly discard.

Based on the findings of the new study conducted by the research team, they put forward the hypothesis that if such a commensal relationship already existed thousands of years ago, this may mean that foxes can be used as indicators of the environmental impacts of ancient humans.

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In the study, the researchers compared nitrogen and carbon isotopes in the remains of different species of large carnivores, herbivores, Arctic foxes, and red foxes obtained from various archaeological sites. These sites were all located in southwestern Germany. The artifacts have been dated to come from the Upper to Middle Palaeolithic Period.

At sites dated over 42,000 years old, at a time when the Neanderthals have not yet fully occupied this region, the diets of ancient foxes have been found to be the same as those of local ancient large carnivores. However, in the younger sites, at a time when Homo sapiens have already colonized the area and were already common there, the diets of the foxes were found to have changed.

Their food preferences became more unique, and it primarily consisted of reindeer meat. Reindeer are too large for foxes to prey on; however, they are known to be an essential part of the diet of ancient human hunters of that period.

The results of the study are suggesting that in the Upper Palaeolithic Period, the ancient foxes shifted their dietary preference from larger predators' scraps to that of the leftover food of ancient humans.

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This is an indication that foxes already relied on leftover food from humans for at least 42,000 years. The study authors proposed that pending further studies and more evidence, this relationship between ancient humans and ancient foxes may mean that fox diets in the past could be used as an indicator of the impact of ancient humans on natural ecosystems from the prehistoric past to the present.

The authors also added that the study's reconstruction of the diet of ancient foxes has demonstrated that ancient Homo sapiens already had a notable influence on the local natural ecosystem as far back as 40 millennia. They concluded that as more humans populated a particular area, the more ancient foxes correspondingly adapted to them.