Foxes’ diets have been found to be influenced by humans, with the small carnivores estimated to being witnesses to human activity over time, according to a new study. Published on July 22, 2020 in the open-access journal PLOS ONE by Chris Baumann of the University of Tübingen, Germany and colleagues, found that foxes also shifted to eating food left behind by humans whenever the latter inhabited an area in prehistoric times.
While Foxes love leftovers, in the wild, they regularly feed on scraps left behind by larger predators like bears and wolves. This predisposition towards scrap food shifts to humans when foxes live closer to human civilization. Their diet begins comprising foods that humans leave behind, based on the existing observations. Considering this tendency of foxes to source their scrap food from humans whenever the latter were nearby, Baumann and colleagues hypothesized that this commensal relationship might go back to pre-historic time as well. Moreover, with further studies, the human-fox relationships and fox’s diets might be a useful indicator of human activity and human impact on ecosystems over time.
Comparing ratios of Carbon and Nitrogen isotopes between the remains of various herbivores, large carnivores, and red and Arctic foxes from several archaeological sites in southwest Germany dating to the Middle and Upper Palaeolithic Ages, foxes diets have been found to be similar to large carnivores with whom their shared their habitat. This is at sites older than 42,000 years, when Neanderthals sparsely occupied the region. But at the younger sites, as Homo Sapien populations grew and became common, foxes’ diet transitioned to reindeer meat, a much larger animal to hunt for a small fox, but was an important game for pre-historic humans of the time.
Based on the findings, the researchers concluded that during the Upper Palaeolithic, these foxes shifted from feeding on scraps left behind by local large predators to the remains left behind by humans. This indicates that foxes’ reliance on human food is a good 42,000 years old. The authors say in the research: “Dietary reconstructions of ice-age foxes have shown that early modern humans had an influence on the local ecosystem as early as 40,000 years ago. The more humans populated a particular region, the more the foxes adapted to them.”