European wildcats are actually shy forest dwellers, but their habitats are increasingly changing, for example due to the expansion of agricultural areas. Researchers have now examined how much human intervention in the landscape and environment influences the animals’ everyday lives and their prey range.
The European wildcat (Felis silvestris) has been protected in Germany since 1935. In the past few decades, this wild relative of our domestic cats has spread again in this country and in Europe. The crepuscular animals, which are considered local loners and usually avoid humans, are increasingly coming into contact with human-dominated environments such as settlements, streets or fields.
“Undisturbed forest areas as ideal habitats for wild cats are becoming smaller, and there is a great risk that they will be run over on our roads,” reports lead author Chris Baumann from the University of Tübingen. Stray, feral or free-roaming domestic cats (Felis catus) also pose a threat to wild cats, as they can transmit diseases or influence their genetic population through cross-breeding.
Searching for traces in the fur of wild cats
However, it is difficult to determine how strong and long-term these developments will have an impact on the way of life and behavior of wild cats. The animals are shy, live in seclusion and can only rarely be observed directly. Baumann and his team therefore chose an indirect approach: They collected tufts of fur and hair from the wild cats in order to subject them to isotope analyses. Some of the fur samples came from an earlier study on wild cats in the Taunus region. In addition, the team used archived hair samples from wild cats in Thuringia that had been collected over many years.
By analyzing the isotopes stored in cat hair, the researchers were able to gain information about the animals’ diet. The ratios of the isotopes of carbon, nitrogen and sulfur are typical for certain food sources and regions. This enabled Baumann and his team
determine which environmental conditions the wild cats have adapted to, where they live and which species they compete with for resources. The long-term samples from Thuringia also made it possible to track changes in diet over a longer period of time.
Narrow niche in undisturbed forest, wide in human-dominated landscapes
The evaluations showed: Wild cats in typical forest habitats such as the Taunus have very similar isotope values. This indicates a stable and comparatively narrow ecological niche, as the researchers explain. Accordingly, these wild cats primarily hunt small forest-dwelling mammals. In contrast, domestic cats and hybrids of domestic cats and wild cats occupy a broader ecological niche and more commonly feed on prey from human-dominated environments.
The long-term data from Thuringia also show a change in the hunting behavior of wild cats. Baumann and his team found that isotope values that indicate prey from agricultural areas are increasingly found, particularly in the fur that grows in the summer. The wildcats now hunt more often outside of their traditional forest habitat in fields and fields. “This result is consistent with recent ecological studies that show European wildcats are increasingly using agriculturally dominated landscapes,” report the biologists.
The team sees these wildcat behavioral changes as a response to pressure from human influences such as the fragmentation or destruction of forest areas and agricultural intensification.
Source: Eberhard Karls University of Tübingen; Specialist article: PLOS ONE, doi: 10.1371/journal.pone.0343705