In this pilot study, hair samples from wildcats, domestic cats, and their hybrids from the Taunus (Hesse) and the Kaiserstuhl (Baden-Württemberg) will be analysed. The aim of the study is to reconstruct dietary niches based on stable carbon, nitrogen, and sulfur isotope values (δ¹³C, δ¹⁵N, and δ³⁴S) and to assess trophic niche overlap among the different cat taxa. This approach allows the reconstruction of average dietary niches over approximately six months of an individual’s life, whereas conventional ecological monitoring methods, such as stomach content analysis, reflect only the most recent feeding event.
Through this project, we aim to gain first insights into the impact of free-ranging domestic cats on the ecology of small wild carnivores using stable isotope analysis. To obtain a more comprehensive picture of dietary preferences and ecological niches, isotope results will be compared with data from existing ecological monitoring methods (e.g. stomach content analysis and telemetry). Where possible, multiple subsamples will be taken from individual hair strands to improve temporal resolution.
For this pilot study, 15 cat hair samples from each of two regions in Germany (30 samples in total) were selected, both of which have been subject to active cat monitoring in recent years. All samples were genetically identified at the Senckenberg Centre for Wildlife Genetics (SGN, Gelnhausen). The Taunus serves as a reference region representing natural wildcat behaviour, as the species has never been completely extirpated there. In contrast, wildcats have only recently recolonised the Kaiserstuhl region from France. The Kaiserstuhl is also characterised by a very high hybridisation rate between wildcats and domestic cats (~40%), which is not observed in most other regions of Germany.
This pilot study therefore compares two contrasting scenarios using stable isotope data: (1) the influence of domestic cats on an established wildcat population (Taunus), and (2) the recolonisation of wildcats into a region dominated by domestic cats (Kaiserstuhl). The latter scenario is currently a major focus of research by geneticists (Dr. Carsten Nowak, Senckenberg Centre for Wildlife Genetics) and wildlife ecologists (Dr. Sabrina Streif, Forest Research Institute Baden-Württemberg), with whom we are in active exchange.
