A new study from the UK debunks the claim that cats need access to the outdoors to supplement their diets with wild kills.
Cats who spend a significant amount of time outdoors and regularly kill local wildlife still get 96 percent of their nutrition from meals provided by their humans, according to research by a team at the University of Exeter.
The scientists connected with cat owners through ads on social media, TV and in print publications, specifically seeking out “cat owners living throughout southwest England whose cats regularly captured wild animals and brought them back to the house,” the study’s authors said.
They gave the owners a questionnaire to collect some basic information on the kitties — age, sex, breed, whether they had unrestricted access to the outdoors, and how much time they spend outside — then split the 90 participating cats into six groups.

To set a baseline, the scientists trimmed small sections of whisker from each of the cats, then trimmed a second sample at the end of the study.
By comparing stable isotope ratios in the whisker samples, they were able to determine what the cats were eating. Despite regular access to the outdoors and successful hunts, pet food accounted for the vast majority of their diets.
As a result, the researchers concluded, outdoor cats hunt because they’re driven by predatory instinct, not hunger.
“When food from owners is available, our study shows that cats rely almost entirely on this for nutrition,” said Martina Cecchetti, the study’s lead author.
“Some owners may worry about restricting hunting because cats need nutrition from wild prey, but in fact, it seems even prolific hunters don’t actually eat much of the prey they catch,” Cecchetti said. “As predators, some cats may hunt instinctively even if they are not hungry – so-called ‘surplus killing’ – to capture and store prey to eat later.”
A second component of the study was designed to find the best mitigation strategy to change the behavior of outdoor cats.
Each group was given a different strategy: In one group, cats were outfitted with bells on their collars, while another group wore reflective break-away collars and cats from a third group were fitted with BirdBeSafe collars. The other groups were told to make habit changes inside the home. For example, one set of cats was fed a higher-protein diet without grain filler, another group was fed with puzzle feeders, and the last group was given extra interactive play time.
While high-protein diets and play time helped cut down on hunting, the BirdBeSafe collars had the biggest impact on hunting success. The collars come in bright colors designed to stand out to avian eyes, taking away stealth and the element of surprise from cats.
The study was sponsored by Songbird Survival, a British non-profit that funds bird conservation research and looks for ways to mitigate the dwindling numbers of many avian species.
Susan Morgan, Songbird Survival’s executive director, said her group hopes cat owners will do their part to help: “Pet owners can help us reverse the shocking decline in songbirds via three simple, ‘win-win’ steps: fit collars with a Birdsbesafe cover; feed cats a premium meaty diet; play with cats for five to ten minutes a day to ‘scratch that itch’ to hunt.”
Of course there’s an obvious solution the study didn’t include: Keeping cats indoors. While keeping cats indoors is common in the US, cat ownership culture in the UK is different — another subject for another post.
Read the full text of the study here. Header image credit Pexels. Body images credit BeSafeCollar.
Previously:
- Reason #53 To Keep Your Cats Indoors: Vigilantes
- Reason #138 To Keep Your Cats Indoors: Mountain Lions
- Reason #127 To Keep Your Cats Indoors: Bad Guys
- Reason #246 To Keep Your Cats Indoors: Coyotes
