Studies such as the Kitty Cams Project, which attached webcams to free-ranging pet cats’ collars, have answered the question that long tantalised cat owners:

Where does Felix go when he slips under the garden gate, and what does he get up to?

Well, he does a lot of lazing about, maybe under cars or on rooftops in the sun. Cats spend 16 hours out of 24 resting.  Felix may also be two-timing you, visiting your neighbours for snacks and snuggles. More seriously, he takes risks: crossing roads; facing off with strange dogs, cats and wildlife; exploring drains and crawlspaces; and sampling unsanitary substances. Male cats are more prone to risky behaviour than females, as are frisky youngsters.

Even more seriously: Felix is probably killing things. Lots of things.

The Kitty Cams Project found that 44% of their feline subjects hunted, bagging on average two prey animals a week. Of these, they left 49% where they’d caught them; ate 28%; and brought 23% home.

Unfortunately, cats don’t limit their hunting to rodent pests; their haul worldwide includes indigenous wildlife species too.

A study in Nature Communications estimates that free-ranging cats (owned pets and feral cats) in the USA kill 1.4-3.7 billion birds and 6.9–20.7 billion mammals annually, making cats the single greatest source of anthropogenic (human-linked) mortality for US birds and mammals.

It’s clear cats pose a biodiversity threat, but many cat owners don’t want to restrict their pets to indoor life. There are simple measures that reduce both the impact of predation and risks to cats from the outdoors:

  • Put a bell on your cat’s collar. This reduces the kill rate by 50-60%.
  • The CatBib interferes with cat’s ability to pounce on prey, but not with other normal activities.
  • Feed your cat regularly.
  • Keep your cat in at night.
  • Keep your cat confined to your garden.
  • Schedule regular play sessions to keep your feline companions entertained and exercised.

It also depends on the cat; some are fearsome hunters while others are mellow fluffballs; some need stricter control because they live on nature reserve borders while inner-city cats seldom encounter wildlife. Older cats also venture out less and most stop hunting by age 13.

–          Olivia Rose-Innes, EnviroHealth Editor, Health24