(Bloomberg) --

Kitty-cams, cameras strapped to cats, have allowed scientists to determine that Cape Town’s felines are slashing populations of some of Africa’s rarest frog and bird species.

The city’s domestic cat population, estimated at 300,000, kills some 27.5 million animals a year, according to a study by researchers at the University of Cape Town in collaboration with the South African National Biodiversity Institute.

“The average Cape Town cat kills 90 animals a year, which can include a number of threatened or endemic species including western leopard toads, cape rain frogs and orange-breasted sunbirds,” the university said Thursday. “The research highlights the need to address the impact of cat predation on Cape Town’s wildlife.”

Kitty-cams are far more effective than traditional predation surveys that are based on questionnaires about the prey the cats bring home. For every five animals killed, only one is brought home by the cat, the study showed.

Reptiles constitute 50% of prey, and the animal most impacted by cat predation is the marbled leaf-toed gecko. A cat-free zone around the borders of the Table Mountain National Park would help, as well as the use of catios, or enclosures that keep the felines in their gardens, according to the researchers.

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