Red foxes and Arctic foxes are already 42 thousand years ago, feed residues produced by man of large herbivores. To reconstruct the diet of these small carnivores managed through isotopic analysis of their bones discovered in the caves of southwestern Germany. The opening not only allows us to understand how members of the genus foxes have learned to get along with people, but also points to the influence of the influence of our ancestors in the Pleistocene ecosystem. The results of a study published in the journal PLoS ONE.
Ordinary, or red Fox (Vulpes Vulpes) are thriving in a world transformed by man. Some populations have even mastered the city, where he adapted not to be afraid of people and look for food among the debris. Arctic foxes (V. lagopus) are also often settle near human habitation in the Arctic. However, how long these two species have begun to benefit from the proximity of the man remains unknown.
To answer this question is decided by a team of archaeologists led by Chris Baumann (Chris Baumann) from the University of Tubingen. They conducted an analysis of fossil bones of foxes and Arctic foxes discovered in the caves of the Swabian ALB (southwest Germany). The findings relate to two time intervals: middle Paleolithic period (more than 42 thousand years ago) and early upper Paleolithic (42-30 thousand years ago). It is believed that in the first period the area was inhabited by Neanderthals, and the second — people of modern type, which belonged to orinyansky and Hrvatskoj cultures.
The aim of the researchers was to determine the diet of Pleistocene foxes and Arctic foxes, for which the team had to turn to the analysis of the concentration of stable isotopes of carbon (13C) and nitrogen (15N) in bone collagen. Two of these marker allow you to set the position of the animal in the food chain, and preferred food. In addition to the estimates for the two species from the genus of foxes in the analysis included the results of isotope analysis of collagen extracted from the bones of a number of species of large predators, large herbivores, hares and rodents. They also lived on the territory of South-West Germany during the Pleistocene.
The analysis revealed in part Pleistocene foxes and Arctic foxes high content of 15N, which indicates that the meat of large herbivores. Of course, this production of the Fox not in the teeth: they just ate food for the more skilled predators. They do so today: for example, Arctic foxes follow polar bears and feed on the remains of their meal. Individual foxes and Arctic foxes was marked by low levels of the isotope 15N. This indicates that they ate mainly rodents, which are caught on their own.
However, some individuals the content of 15N was intermediate, that is, they supplemented the diet of meat reindeer rodents. This diet was typical for foxes and Arctic foxes, who lived in the early upper Paleolithic. Because the isotopic composition of their collagen is not the same as that observed for large predators, it is unlikely they was their the commensals. Most likely, these foxes from time to time fed on the remains of animals killed by people. They could how to pick up the pieces, the split of production in places of hunting, and steal scraps of food near the caves. This hypothesis seems especially compelling when you consider that the reindeer people have mined the most.