This sort of pet cat study about predation on wildlife in the UK is another example of pressure being placed on domestic cat owners to keep their pets inside 24/7. There is a shift towards this sort of cat ownership. As studies constantly highlight the high numbers of wild animals killed by domestic cats, cat owners are pressured to keep their cats inside. This is the intention of the study authors. Keeping cats inside 24/7 places extra obligations on owners. Can and do they meet those obligations?
In general, cat owners do not consider the damage caused to wildlife by their domestic cat’s predation. If they keep their cat inside it is to protect the cat from road traffic accidents, in Britain, and from other predators such as coyotes in America. The motivation is to protect the cat not wildlife. This needs to change in the minds of millions of people. You don’t need to be a conservationist to want to protect wildlife.
I can refer to a recent study which has been reported in the Times today. In summary, the scientists found that pet cats in Britain’s suburbs may be killing up to 270 million animals a year. They state that “the 9.5 million pet cats in Great Britain may kill in the region of 160-270 million prey individuals per year” in their words.
They state that cats that live in urban areas but near non-urban areas i.e. on the boundary between these two types of landscape kill more wildlife because they venture into the non-urban areas when they roam. Cats near the natural landscape wandered over 8.5 acres whereas those in urban areas wandered over 5 acres.
They found that some “boundary cats” (those cats living on the boundary between urban and non-urban areas) travelled up to 300 meters inside the natural area. On average they travelled about 65 meters into these natural habitats. Boundary cats preyed on more animals but the increase was always on ground dwelling creatures. There was not an increase in predation on birds by boundary cats. They killed three times more mammals, however.
The scientists decided that Britain’s domestic cats kill 270 million animals by extrapolating their study which involved tracking and assessing 79 owned cats to the entire British population of domestic cats. This is always problematic. I’m not sure that this has been critically examined by the experts.
A further potentially problematic aspect of this study is that they do not refer to the usefulness of predation on mammals such as mice and other rodents. What about rats? Domestic cats deter rats and sometimes they kill rats. They kill lots of mice. They kill more mice than they do birds. Not long ago Australia had a plague of mice and I wondered whether the cause was the ongoing mass extermination of feral cats on that continent. Do we know what would happen if there were no predation by domestic cats in the UK? Would there be an explosion of pest animals?
Another aspect of the study which is open to criticism is that they don’t tell us whether the predation by domestic at on animals harms in any way the population sizes of these animals on a permanent basis. In other words, can the population of these prey animals absorb predation by domestic cats and still thrive?
A further issue is that domestic cats have an impact on the survivability of wild animals not through direct predation but by the cats’ presence. This is called a “sub-lethal fear effect”.
Dr. Tara Pirie, the lead author of the study, said “Just the presence of a predator can cause wildlife to change their behaviour, either reducing feeding through heightened vigilance or staying away from a nest leaving it exposed, for example. This can reduce the survival of both adults and offspring.”
She also mentions the zoonotic disease Toxoplasma gondii and its transference from domestic cats to wildlife which she says reduces their survival rate.
The study is published in the journal Landscape and Urban Planning as the study’s findings can I have an impact upon urban planning.
The study has been published, as mentioned, in The Times. This is mainstream reporting of just another study about domestic cat predation. But I sense that there is a buildup of pressure against domestic cat owners to think about conservation when they allow their cat to go outside in addition to the safety of their cat.
Below are some more pages on predation.