Cats' catastrophic impact on biodiversity

Various international studies have found that domestic cat predation has a negative impact on mammals, reptiles, birds and other animals. Mike Burgess looks at the findings of a South African study done in 2020.

- Mike Burgess

Despite domestic cats (Felis catus) being much-loved pets, they also double as the most widely distributed carnivore on earth. For this reason, cat owners should keep them in at night.

Most house cats rely on pet food for sustenance but their instinct drives them to hunt. For example, studies done in the US show it is likely that domestic cats kill up to 3,7 billion birds and up to 20,7 billion mammals each year, while another study indicated that about 460 million mammals are killed annually by cats in Australia.

SOUTH AFRICAN STUDY

A 2020 study by the University of Cape Town and the South African National Biodiversity Institute collected similar statistics about the predatory impact of domestic cats on the biodiversity of the Western Cape and South Africa as a whole.

The study, based in Cape Town, found that domestic cats occurred at an average density of 150 to 300 individuals per square kilometre in the suburbs of Cape Town – 300 times the density of caracal and African wild cats in the wild.