European wildcats and domestic cats have coexisted since farmers entered Europe 6000 years ago. Weirdly, humans made surprisingly little difference. Research in @PNASNews finds huge overlap in diet among Neolithic domestic and wildcats. doi.org/10.1073/pnas.1… 
When human farmers entered Europe, they started altering the landscape. Manuring fields and growing crops shifted the isotopic signature of the soil. Higher nitrogen-15, which concentrates up the food chain, is even more enriched in humans and our domesticates.
The shift in isotopes is detectable in human bones and teeth, and dogs, sheep, and cattle. High 15-N means people and dogs look like the absolute top of the food chain, even compared to wild carnivores like foxes and wolves. Results from Krajcarz et al doi.org/10.1073/pnas.1…
So what about cats? Domestic cats evolved from wildcats from southwest Asia, became commensal with people, and came into Europe with early farmers. People liked them for many reasons, including control of crop and granary pests like rodents.
You might expect that early European domestic cats would have a dietary niche aligned with people, eating lots of crop pests. But actually, Krajcarz and coworkers found that the domestic cat 15-N values were the same as wildcats of the same time.
The domestic cats were more constrained in niche compared to wildcats, and that shows up in the wider spread of wildcats in carbon-13. Why? Maybe eating more wild birds (which have high carbon-13). But both kinds of cats were clearly eating lots of non-commensal small animals.
There's a big underlying message here for cat-lovers. Even in the early days of domestication, domestic cats relied enormously on predation of wild birds and small mammals. They were dietary wildcats that tolerate being close to people. They still are.
There's a message here for people, too. Early Holocene people had such an huge landscape impact that we created new niches for predators living in our midst. Cats were among the most rapid to evolve in our wake. That evolution of wild species is still happening.
