What are the consequences of killing feral cats in large numbers? Many people want to eradicate them entirely from North America. They say they are an invasive species but overlook the reasonable argument that home sapiens could also be defined as an invasive species in countries and continents other than Africa. They say that the feral cat slaughters millions of birds yet overlook research that indicates that the cat prefers ground dwelling animals (rodents) and catches old and dying birds. The say that the feral cat breeds at fantastic rates and produce simplistic calculations yet overlook high mortality rates of feral cats.
Another important factor that these people overlook is they have no idea what the consequences will be to native species including birds of removing large numbers of feral cats.
They naively presume that all will suddenly and automatically be well. A new utopia will be born. No feral cats, plenty of beautiful birds. But will that be the case?
Cats were originally domesticated to control rodents some 9,000 years ago. Feral cats have been in the United States for hundreds of years. They are part of the ecosystem. If you remove one element of that ecosystem you may well unleash unexpected consequences.
We don’t ask what the consequences might be. We don’t assess the whole thing holistically. What if the population of rats and mice surged as a result of the extermination of feral cats. Rats sometimes attack and eat young birds. Mice are known to eat young chicks on the nest too. It may well be that more birds will be killed by rodents if feral cats were exterminated. What about other small mammals in the USA that are preyed upon by feral cats and which can cause damage to property? Apparently chipmunks burrow in walls and can undermine foundations. Chipmunks also prey on bird eggs and nestlings. I am sure there are other examples and perhaps more complicated ecosystem scenarios that may be upset in ways that are yet to be assessed if the feral cat is removed from the ecosystem.
I am not a scientist but it is clear that feral cats can serve a useful purpose that is largely unrecognised. As mentioned they perform their original role of 9,000 years ago – keeping the rodent population down. This is an almost invisible role until we remove the feral cat.
I am not trying to predict an outcome. I don’t know what would happen if feral cats were removed. I am just saying that people who want to kill feral cats to save birds are oversimplifying the matter and failing to assess the situation properly.
I haven’t mentioned the obvious fact that gassing and shooting feral cats is inhumane and I think immoral. That alone should be good enough reason not to try and exterminate them. But thinking through the consequences in a holistic and thorough manner may also prove to be another very good reason to reassess the simplistic notion that you can just kill feral cats to improve the environment.