In the not too distant future there will be two alternatives to TNR as a means to manage the feral cat population in any country but I am mainly thinking of America and Australia where the authorities are more concerned about the impact that the presence of feral cats have on wildlife and people.
Science has developed to the point where governments can consider editing the genes of feral cats to stop the production of females. It will be a humane alternative to trap-neuter-release (TNR). Currently TNR is the only humane method to control feral cat numbers in the long term. It is a slow process but it is a moral process.
Scientists at the University of Edinburgh’s Roslin Institute are investigating a technique called X-shredder. It involves trapping thousands of male grey squirrels and injecting them with a substance which destroys the X-chromosome during sperm production. Their gametes would only carry the Y chromosome resulting in their offspring being male only.
These would be gene-edited squirrels. The objective: to gradually reduce the number of grey squirrels in the UK to protect trees and red squirrels and to consequentially enhance the project to tackle climate change.
This technique, I would submit, might be applicable to the “feral cat problem”. It would certainly reduce feral cat numbers over time in a controlled way and could be incorporated into TNR projects. When an individual male cat is trapped and neutered by a veterinary technician that person could inject the substance which means that the cat can only produce male offspring. If the only offspring are males then it’s impossible for procreation of feral cats to take place in the longterm.
As for squirrels they say that under this technique the grey population will be reduced by more than 60% within 10 years of the gene drive starting. Within 20 years the grey squirrel population would be eradicated they say. Could those projections apply to feral cats. Nice thought if they did.
Males would be targeted because they’re more promiscuous. Another option would be to edit genes so that any female feral cats born would be infertile. This would result in more and more males in comparison to females until the population reduces dramatically in numbers.
An existing alternative to managing squirrel numbers is to use oral contraceptives. This is being studied by the Animal and Plant Health Agency. Has this been considered for feral cats in the USA?
It’s a way that science can find a solution to the problem that feral cats present. Personally, I am untroubled by the presence of feral cat except in respect of their welfare and well-being because it’s a tough life and a short one, normally. And, of course, a better solution would be to ensure that feral cats are not created through human carelessness. Improvements in cat ownership would be the better method but that’s an ideal which might be unattainable. There will always be some careless people. They will always be in sufficient numbers to allow domestic cats to procreate, those cats become unwanted and then they become feral and then they further procreate to create a large population.
In America, it is thought that the population of feral cats is similar to the size of domestic cats which would mean that there are about 90 million of them in America but people don’t know. I’ve seen various estimates of the numbers from something around 15 million to 90 million as stated. Let’s say there’s a large number of them.
There are many brilliant volunteers who operate TNR programs and on ther side of the coin there are many people who hate feral cat. They are sometimes cruel to them. Further there are many local authorities who scratch their heads about how to deal with them and they nearly always come back to TNR as the best method because there is no decent alternative. The one mentioned on this page may be a decent alternative which they can consider now and going forwards.