Based on a scientific study carried out in America over the period November 2010-October 2011, it was found that 44% of domestic cats allowed outside (free-roaming cats) hunted wildlife. Of course, this is one study about domestic cats in a suburban area of the south-eastern USA. I believe it took place in suburban Athens, Georgia, USA.
However, it is these kinds of studies that the anti-cat brigade use to denigrate the cat. They extrapolate small studies like this one and generalise on them. Well, here we have a study which says that four out of every 10 domestic cats kill wildlife primarily reptiles, mammals and invertebrates.
When people are assessing the impact of the domestic cat on native species it would seem to be unwise to presume that all domestic cats hunt wildlife. If they presumed that about half of domestic cats hunted you would probably halve the estimated number of birds and other animals killed by domestic cats annually.
The study monitored 55 cats over a 12-month period. They say that “successful hunting cats” captured an average of 2.4 prey animals during seven days of roaming. Most of the predation occurred during the warm season namely March-November. Thirty-three percent of the prey items were brought back to the home while 49% of the items were left at the place where they were attacked and captured. Twenty-eight percent were eaten.
At that time, they concluded that the predation rate of domestic cats was higher than expected. Over the intervening 11 years, I would suggest that there has been an exaggeration of the impact on wildlife by domestic cat predation and therefore these figures would indicate that it is less than currently believed.
The study: Quantifying free-roaming domestic cat predation using animal-borne video cameras.
Another study on stray cat predation
In a separate study published in 2018, they found that stray cats living in a colony hunted far more frequently. We don’t know whether this colony was managed by TNR volunteers who fed the cats. I suspect not which would account for the higher predation rate. They monitored 29 cats using Kittycam video cameras (video cameras on collars).
In total, 24 of the cats hunted and, of those, 18 captured prey animals. In percentage terms, 83% of the stray cats hunted while 62% killed wildlife. The success rate of those cats that hunted was 44%. The most common animal captured was an invertebrate, mainly insects followed by amphibians and reptiles. Eighty-three percent of the kills took place between dusk and dawn. This supports the view that domestic cats are crepuscular and they hunt at night primarily. Although they do sometimes hunt during the daytime as well.
This study is called: The use of point-of-view cameras (Kittycams) to quantify predation by colony cats (Felis catus) on wildlife.
I find it intriguing that the main prey animal was an insect. That certainly goes against the grain. This might surprise ornithologists. Incidentally, the insects were mainly grasshoppers, crickets, aphids, cicada, or leafhopper (Orthopteran and Hemipteran insects).
Comment: the main prey animals of the domestic, stray and feral cat must depend on the location where they live and prey abundance but as a whole, they will be mice, reptiles, insects and birds.
Contextualizing the predation of reptiles by cats in Australia