Domestic cats hunt 2,084 species of animals – 12/13/2023 – Science

“They are among the most problematic invasive species in the world”, “they have had a destructive effect on many of the ecosystems into which they were introduced”, “they have driven many species to extinction”: the phrases, coming from a study that has just been published, refer to the simple domestic cat (Felis catus). The work mapped for the first time the global impact of cats when they act as predators, and the result is not pretty: they hunt at least 2,084 species of animals, of which 347 are at some risk of extinction.

In a sense, the apocalyptic numbers are expected: previous research, carried out on a regional or continental scale, had already shown that cats are capable of causing considerable damage to the biodiversity of the places where they live. In American territory alone, previous calculations had shown that animals kill a few billion birds every year.

The team led by Christopher Lepczyk, from the College of Forestry, Wildlife and Environmental Sciences at Auburn University (USA), gathered and analyzed more than 500 previous studies on the feline threat, giving preference to those that more accurately identified the species preyed upon by cats. domestic animals. More than half of the data comes from research carried out in Australia and North America – in tropical regions, such as South America and Africa south of the Sahara, studies on the topic are still relatively rare.

Almost half of the species normally captured and devoured by domestic cats are birds (981 in total). This means that almost 1 in 10 of the birds that exist today are eaten by animals. Then come reptiles (22.22% of preyed animals) and mammals (20.68% of species on the list), followed by insects and amphibians, says the research, which has just been published in the specialized journal Nature Communications.

On the one hand, most studies list species seen as pests among cats’ prey, probably the reason why they were domesticated thousands of years ago. Among the usual suspects are mice (Mus musculus) and two types of mice (rattus rattus It is Rattus norvegicus), as well as sparrows (Passer domesticus) and European rabbits (Oryctolagus cuniculus). The latter are also an invasive species that has multiplied beyond control in places like Australia.

The problem is that the feline menu is not restricted to these very common animals. Among the other prey consumed by them are 7% of the birds threatened with extinction on the planet, as well as 5% of mammals in the same situation. In fact, there are records of cats devouring 11 species that are now classified as extinct or extinct in the wild (that is, they only exist today in captivity), including the Hawaiian crow (Corvus hawaiiensis).

As you would imagine, the animals captured by cats are normally small (weighing, on average, 50 grams), but there are records of predation on much larger animals, such as the American bullfrog (Lithobates catesbeianus), which weighs up to half a kilo.

The damage caused by cats in most ecosystems around the world derives, in large part, from the fact that they are a newly arrived species (as they originally evolved in North Africa and the Middle East before being domesticated). This means that in many places, its prey have not developed natural defenses against it. This is especially true in the case of islands and archipelagos where there was no native fauna of terrestrial mammals, or where there were only marsupials and monotremes (such as kangaroos and platypuses, respectively) – the latter is the case in Australia.

Minimizing the problem is possible with some simple measures. Cat owners must prevent their animals from leaving the house unsupervised, for example. It is also important to encourage neutering to avoid the birth of unwanted puppies, which could end up living freely and multiplying the feline population even further.