Cats kill much more prey than wild predators of similar size and do not have to travel great distances to do so. The territory of a domestic cat is about 100 meters around the house where they live.
Roland Kays, the lead author of the study and zoologist at the Museum of Natural Sciences of North Carolina, said that “We were able to find that domestic cats have a 2 to 10 times greater impact on wildlife than wild predators, a very surprising effect.
To carry out the study, 925 domestic cats used to go out to six different countries were equipped with GPS devices, allowing them to monitor their behavior and track them. Besides, scientists and citizens used the data obtained to track the movement of cats, as well as any prey caught and taken home in rural and urban areas in the United States, the United Kingdom, Australia, and New Zealand.
Roland Kays explains that “Many people feed domestic cats, which is why they should kill less prey a day than wild predators, but because their field of action is smaller, their action on prey has a greater and more concentrated impact. Not only that, but the population density of domestic cats in some areas also has a major impact, thus putting the population of birds and small mammals at risk”.
The study found that domestic cats on average kill an amount of prey ranging from 14.2 to 38.9 per 100 acres in a year, the equivalent of about 3.5 prey per cat each month. The researchers believe that the high number of prey is because inner-city neighborhoods have a high density of domestic cats, many more than wild predators living in the wild.
Roland Kays explains that “We knew that domestic cats kill a large number of prey, ranging from 10 to 30 billion wild animals a year, but we didn’t know the extent of the area in which they act, nor the comparison with the wild free ones in nature. The area most affected is the one that already suffers disturbances on wildlife, among the causes are the housing development that disturbs natural habitats.
Cats, unlike other predators such as the coyote, have not been discouraged by other predators within their range in the areas where they live.
The authors of the study explain that “domestic cats worldwide have a significantly greater ecological impact than native predators and are concentrated as an area about 100 meters from their homes. researchers are unable to say which native species might persist and be able to recolonize urban areas if domestic cats were not present.
In short, domestic cats are probably the most numerous carnivores on Earth, reaching 600 million pet cats worldwide. This large number of cats could lead to the ruin of native species. Fortunately, domestic cats have no impact on species living in larger protected areas, but only in urban and suburban habitats.
The study found that among the most endangered native species are Brushtail possums in southern Australia and endangered rodents and rabbits in North America. Domestic cats, given their size, hunt small mammals that can be easily caught and killed. Researchers explain that one way to prevent the impact on wildlife would be to keep domestic cats in their homes.
Rob Dunn, co-author of the study, and William Neal Reynolds, professor of applied ecology at North Carolina State University, explain that “As the negative impact of cats develops locally, an area should be created where the positive aspects of wildlife such as bird song or the beneficial effects of lizards on pests can proliferate, as they are becoming less common where they would be most valued. Humans find joy in biodiversity, but by leaving cats out in the open air, a world has unintentionally been designed where the joys of wildlife are increasingly difficult to live in.