Updated: Oct 9, 2020
There is a killer stalking the forests and glens of Argyll. He can strike at any time, carefully studying his victims before pouncing.
All of the deaths have common features: they occur randomly, without warning – the bodies left exposed. The victims too share characteristics. They are nearly always diminutive types, the kind that most people wouldn’t even register, let alone notice.
And the killer himself is unnoticeable, quietly going about his everyday activities. He too would hardly receive a second glance in the street.
His name is Tom and he is my cat.
Well, when I say my cat, I mean that he lives under the same roof as me, is petted by me and relies on me to open up his cans of cat food – at least until he works out how to use a tin opener. He can be amazingly affectionate, when he feels like it of course, but he leads a double life: one as a charming, funny, affectionate and purring bundle of fur and the other as a nasty, vicious and marauding rodent molester.
I have done just about everything to stop him: given him a collar with a bell; kept him indoors during the evening; rescued countless small furry lives in the nick of time; kept him well-fed and given him toys.
It’s not enough though, because even a short time outside ends with rodent bodies being left in various states of dismemberment on the lawn somewhere. This seems to be his preferred prey, because I have not to date seen him with a bird or found one dead. It hasn’t stopped him trying, of course, although he really doesn’t have a clue about size ratio, having tried to tackle crows and even a raven that was big enough to make mincemeat out of me, let alone a small cat. His ambitious attempts to stalk other animals have even seen him trying to take on a Sika deer - which promptly turned on this interloper and chased him into a pond.
But his antics are more than just a little annoying. It got me considering what effect his activities are having on the local wildlife. I don’t just mean the obvious one of killing mice, but the combined effect on the food web.
Cats are notorious killers and there are millions of cats. The RSPB estimates there are 8 million of them in the UK alone; another 30 to 80 million feral cats in the United States. Each one is definitely going to kills small animals at some time although hard evidence is difficult to come by. By my estimates, my cat alone is on track to take out anything from 250 to 700 or more mice or voles and the more occasional shrew a year. This in a relatively small area of grassland and woods alone. The mind boggles to consider the collective killing capacity of the world’s population of felines.
So let’s not beat about the bush. The loss of hundreds of rodents will have some kind of impact on other wildlife; the issue is ‘what’?
Other animals eat small mammals too and these include raptors, such as buzzards, foxes, badgers and owls. Quite how many each species relies upon as part of its food sources is unclear, although sources suggest that barn owls, for instance, will take up to 3 voles a night (for more info read about the work of The Barn Owl Trust HERE). It follows, then, that a reduction in rodent populations, including shrews (which are not actually rodents but belong to a group of insectivores called Eulipotyphla) will have an impact on populations of their predators.
Such impacts might vary, of course. It may be that in the absence of their favourite prey these animals will turn to other sources. Owls, for instance, may increase their reliance on amphibians. In turn this may drive down frog or newt populations, affecting other ecosystems and their natural predators. It may also be argued that a reduction in rodents allows for reduced competition amongst them, driving up their numbers and thus actually increasing their populations, or at least counterbalancing your cat’s instinct to hunt everything that is small, squeaky and crunchy.
It is without a doubt that human activity directly and indirectly affects ecosystems across the globe. Our ability to do everything from dragging natural resources out of the ground, remove entire forests and cover the planet in concrete affects, changes and often wipes out species and their habitats.
Your cat, small as it is, is another symptom of these activities and we as humans are ultimately responsible for introducing them. Let’s try and mitigate our destructive behaviour and at least begin to understand what we are doing.
At least then will we be in a position to try and reverse the damage.
©Nick MacIneskar 2020