A new report in Nature suggests that domestic cats, primarily un-owned, are responsible for an estimated 6.9 to 20.7 billion animal deaths every year. While the majority of animals killed were by strays, feral and farm cats, a significant number were from pet cats.

Here we conduct a systematic review and quantitatively estimate mortality caused by cats in the United States. We estimate that free-ranging domestic cats kill 1.4–3.7 billion birds and 6.9–20.7 billion mammals annually. Un-owned cats, as opposed to owned pets, cause the majority of this mortality. Our findings suggest that free-ranging cats cause substantially greater wildlife mortality than previously thought and are likely the single greatest source of anthropogenic mortality for US birds and mammals.

This number is comparable to the nine billion chickens that are eaten every year in the US. To put it in further perspective, this is 250 – 800 times the number of animals used each year in the US for medical research. To put it another way, in 2013, cats will kill a larger number of animals in one year than have ever been used in research in the US.

We have already pointed out that food, hunting and driving are all activities responsible for far more animal suffering than animal research.

The timing of this report coincidentally came a few days after the animal rights activist, Rick Bogle, wrote an article where he discussed whether or not we could measure, in a comparable way, different types of animal suffering. Bogle’s objective was to show that animal research would be more cruel than many other common deaths suffered by animals. He notes:

The suffering of a squirrel who darts out in front of a car and is hit might be as horrible as the suffering of a rat whose spine has been crushed in a lab, but on a cruelty scale, a scale of hideousness, they do not seem to be very similar.

Bogle, as usual, neglects to mention that any research studying spinal damage could only legally occur if the animal was anaesthetised. Furthermore, such experiments would offer hope to the many humans and pets who suffer paralysis from spinal injuries. He also fails to acknowledge that many squirrels hit by a car are not killed outright, and, whereas a suffering animal in a lab will be put down, nature has no such compassion.

Bogle also picks examples of animal suffering that are linked to human activity, choosing not to mention the rampant bloodshed that occurs in nature. Few non-domestic animals in their natural settings will live to old age; instead they will be finished by starvation, predation or disease. The many mice and birds killed by cats (not to mention those who escape injured), will suffer considerably more than in almost any lab experiment.

Put together, we can see an absurdity in any animal rights philosophy which gives animals a right not to suffer. Such a right would entail human intervention to prevent it – not just an abatement of our uses of animals, but a war on nature itself.

Tom Holder

Loss, S.R., Will, T. & Marra P.P., 2013. “The impact of free-ranging domestic cats on wildlife of the United States” in Nature Communications.