Cape Town's killer cats prey on 27 million local animals every year, study finds

The average Cape Town house cat kills about 90 animals a year, according to researchers.

Local scientists have published a new paper looking at how domestic cats may be contributing to the extinction of indigenous species in Cape Town.

The study, titled Caught on camera: the impacts of urban domestic cats on wild prey in an African city and neighbouring protected areas, was published last week.

The study compares existing data with video footage of some of the cats wearing animal-borne video cameras (KittyCams).

The KittyCams reveal that most cats prey on animals at night. Only 18% of prey recorded on video were returned home.

This suggests that cats kill at least 5 times more animals than the kills they return home with.

A co-author of the study, Dr Robert Simmons says the average domestic cat kills about 90 animals a year in Cape Town.

According to Simmons, there are approximately 300,000 cats in homes across the city.

This means that between 27 to 28 million animals are killed by domestic cats annually in Cape Town.

Thousands of these wild animals are killed on the edges of Table Mountain National Park, and many of them are endangered.

The study reveals that 80% of all kills are never taken home or even consumed.

Cats enjoy killing reptiles the most followed by small mammals and birds.

Dr. Simmons says 14 million reptiles are killed annually, many of which are geckos.

Cats are also targeting squirrels, geckos, and even hadedas.

Worryingly, he says the felines are killing the endangered western leopard toad, the Cape rain frog, sugarbirds, the orange-breasted sunbird, and the Cape weaver.

The study showed that some cats were not bringing home any of the prey, but they were killing on camera.
Dr Rob Simmons, Senior lecturer - Percy FitzPatrick Institute of African Ornithology at UCT

If your cats haven't brought anything home, that's not a guarantee that your cats aren't killing quietly in the background.
Dr Rob Simmons, Senior lecturer - Percy FitzPatrick Institute of African Ornithology at UCT

We've got about 300,000 cats in Cape Town altogether. If 300,000 cats take about 90 prey per year, then we're talking about 27 to 28 million animals killed per year in Cape Town.
Dr Rob Simmons, Senior lecturer - Percy FitzPatrick Institute of African Ornithology at UCT

Cape Town's cats are actually reptile specialists. The poor little marbled leaf toed gecko is their favourite snack.
Dr Rob Simmons, Senior lecturer - Percy FitzPatrick Institute of African Ornithology at UCT

They don't bring these things home, in general. They either eat them in situ, abandoned them in the field and don't bring them home.
Dr Rob Simmons, Senior lecturer - Percy FitzPatrick Institute of African Ornithology at UCT

Dr. Simmons says it's difficult to tell how much this predation by domestic cats is threatening the existence of the endangered prey species.

He believes that Cape Town authorities should start limiting the number of domestic cats in households due to the impact on animal populations.

Researchers are engaging with SANParks about building ecological buffers to create cat-free zones, especially along Table Mountain National Park, he tells CapeTalk.

Listen to the discussion on Afternoon Drive with John Maytham: