Domestic cats are widespread worldwide and often threaten local wildlife. A study now shows that velvet paws are by no means picky when choosing their prey. More than 2,000 species are on their menu, including many species that are threatened with extinction. According to the research team, a better understanding of the dietary habits of domestic cats can help take more targeted measures in the future to curb the damage they cause.
Since cats were domesticated over 9,000 years ago, they have traveled with us humans to all parts of the world. Today they are found on every continent except Antarctica. However, stray cats and outdoor cats pose a problem for the respective ecosystems because they hunt small mammals, birds and many other animals, raid nests, spread diseases and displace other small native predators. The ecologically devastating effects of velvet paws have already been assessed for many individual areas. However, a comprehensive overview has so far been missing.
More than 2000 species on the menu
A team led by Christopher Lepczyk from Auburn University in Alabama has now compiled previously available studies and documented on a global level which animal species are eaten by domestic cats and what this means for the respective ecosystems. Lepczyk and his team evaluated a total of 533 studies from all parts of the world. They came up with 2,084 species that are on the diet of domestic cats. “These 2,084 species represent a conservative estimate,” write the researchers. “We expect that we will discover many more prey species as further studies are carried out.”
While widespread species such as house mice and sparrows often end up in cats’ stomachs, free-roaming or feral house cats also eat many other, often rarer animal species, including 981 species of birds, 463 species of reptiles, 463 species of mammals, 119 species of insects and 57 species of amphibians. Fish, snails, spiders and other arthropods accounted for 33 other species. Birds make up the largest proportion of species eaten by cats on every continent. However, there are differences in second place. Reptiles were the second most common prey in Africa, Asia and Australia, while mammals were the most common prey in Europe, North and South America. According to previous studies, cats in Africa eat more insect species than mammal species, to the researchers’ surprise – even though many African insect species have not yet been systematically recorded and are therefore probably still underrepresented.
Extreme generalists
“Of the species consumed, 347, i.e. 16.65 percent, are on the IUCN Red List as at least potentially endangered,” the team reports. 2.21 percent of the species are at acute risk of extinction. Eleven species that were identified as cat prey in previous studies are now extinct in the wild, including the Hawaiian crow, which now only exists in human care. “On islands, the proportion of endangered species in the cat diet is even higher at 25.22 percent, perhaps due to the lack of coevolution between prey and predator and the fact that many endangered species only occur on certain islands.”
In addition, Lepczyk and his team found that cats do not only eat small animals. “Although 97 percent of the species consumed have a body weight of less than five kilograms, cats also eat much larger species,” reports the team. These include emus, green sea turtles and even cows. Cats do not usually hunt such large animals themselves. Instead, they capture them from other predators or humans. In some cases they do not eat the adults, but instead feast on the eggs or young animals. “Our results show that cats are extreme generalists,” write the researchers. “This has implications for understanding their impact on ecological systems and is crucial for developing management solutions.”
Source: Christopher Lepczyk (Auburn University, Alabama, USA) et al., Nature Communications, doi: 10.1038/s41467-023-42766-6