Differential predation patterns of free-ranging cats among continents

Co-evolutionary relationships associated with biogeographical context
mediate the response of native prey to introduced predators, but this
effect has not yet been demonstrated for domestic cats. We investigated
the main factors influencing the vulnerability of prey species to domestic
cat (Felis catus) predation across Australia, Europe, and North America,
where domestic cats are introduced. In addition to prey data from
empirical records, we used machine-learning models to compensate for
unobserved prey in the diet of cats. We found continent-specific patterns
of predation: birds were more frequently depredated by cats in Europe and
North America, while mammals were favoured in Australia. Bird prey traits
were consistent across continents, but those of mammalian prey diverged,
notably in Australia. Differences between prey and non-prey species
included mass, distribution, and reproductive traits, except in Australian
mammals where there was no evidence for a relationship between mass and
the probability of being prey. Many Australian mammal prey also have a
high extinction risk, emphasizing their vulnerability compared to European
and North American counterparts. Our findings highlight the role of
eco-evolutionary context in assessing predation impacts and also
demonstrate the potential for machine learning to identify at-risk
species, thereby aiding global conservation efforts to reduce the negative
impacts of introduced predators.