Diet of the feral cat, Felis catus, in central Australian grassland habitats: do cat attributes influence what they eat?

The house cat Felis catus was introduced to Australia as a pet and means of rodent control over 200 years ago, but now has established feral populations and has become a serious threat to native wildlife. Using stomach content analysis of 73 feral cats from semi-arid grassland habitats in Queensland, Australia, we aimed to identify dominant prey groups in the cats' diet and to explore associations between the diversity of prey eaten and attributes of the cats including body size, condition, sex, age and coat colour. We also sought to determine any relationships between cat size and the size of the dominant prey in the diet, the long-haired rat Rattus villosissimus. Mammals and reptiles were the dominant prey, with R. villosissimus occurring in 60 % of samples and comprising more than half of all prey by volume. Birds and terrestrial invertebrates were the next most important contributors to the diet, but fish, frogs and freshwater crustaceans also were surprisingly well represented. The dietary diversity of cats was largely unrelated to any of the cat attributes that we measured, although a positive relationship emerged between cat head width and the range of prey types eaten. Our study was conducted during a population irruption of R. villosissimus and confirms that cats are able to exploit an abundant focal prey resource when the opportunity occurs. Further research now is needed to explore associations between diet and cat attributes during periods when rats are scarce.