What is a feral cat?
Feral cats are different from wild cats. A wild cat, such as 'Felis Sylvestris' in Britain, is a part of the native fauna, and neither it nor its ancestors has ever been a domestic pet (at least not to anyone who managed to keep a whole skin). On the other hand, feral cats are cats, or the progeny of cats, which have either been abandoned by their owners, or which have abandoned their owners (the process works both ways). In many countries wild cats are protected by law, yet feral cats are regarded as little better than vermin. The problem is compounded by irresponsible cat owners who believe that, if abandoned, their pet will 'revert' to the wild, and happily adapt to looking after itself. In fact, the majority of abandoned pets lead unhealthy, miserable and short lives.
Whereas wild cats are a part of the local ecology, and are generally solitary, feral cats sometimes form colonies (also known as 'clowders') the size of which is limited only by the available food supply. If that food supply consists of an endangered small mammal or bird, the effect of feral cats on the environment can be devastating. Indeed, it has proven necessary for some smaller islands off the coast of New Zealand to be carefully cleared of feral cats. As a result, ground-nesting seabirds are making an appearance to breed on those islands for the first time in decades, or even centuries. In some countries, such as the UK, feral cats easily outbreed the domestic population, so many a house cat has been obtained as a kitten from a feral colony. Most feral cats are short-haired, and even long-haired breeds tend to revert to short-hair after a few generations of living wild.
Where are feral cats found?
The short answer is almost anywhere. There are, for example an estimated million feral cats (at least) in the United Kingdom, and several times that number in the USA. The cat is a highly adaptable species, and has the advantage of being able to live on rodents, which are themselves able to live almost anywhere. Cats adapt easily to open countryside and woodland, but because they have a high-protien diet, they fare least well in areas where their prey disappears in winter. Also, having evolved in a warm, dry climate, cats in a cold damp environment tend to have shorter and more miserable lives. Cats do particularly well in open grassland, as they have evolved to get their body moisture from the prey they consume, and so need very little water.
By definition, feral cats are accustomed to humans and a human environment, so almost every city in the world has a population of feral cats. These cats are often blamed for tearing up rubbish bags and digging up gardens, and there can be no doubt that their faeces, urine spraying, and noisy mating and fights cause distress to many urban humans.
However, it should be noted that feral cats in cities do a job of rodent control which in a fairer world would get them reclassified as unpaid health and sanitation workers. Furthermore, those who accuse cats of ripping up rubbish bags might be surprised at the number of urban foxes and even large birds such as magpies which also regard rubbish sacks as goody bags of useful diet supplements.
Cats (and not just feral cats) have been accused of massacring the songbird population of the suburbs. However, it has been shown that the number killed by cats is much smaller than the number of birds killed directly by humans who erect glass windows for birds to fly into, drive cars at them faster than the birds expect, or hack down their nesting areas for car parks and patios.
What can be done about feral cats?
For centuries, the human response to having feral cats about has been to kill them. There are of course many exceptions to this - some farms positively encourage a small number of feral cats for help in keeping down rodents, and many factories like to have a few cats about for the same reason. There are also many animal lovers who actively encourage the presence of feral cat colonies by feeding their members.
The fact is that, after centuries of attempts at extermination, the feral cat has proven more wily and resilient than its would-be exterminators. One reason is that feral cats are relentless breeders. Cats are sexually active within 12 months of birth, and the menopause is unknown to feline females, which breed throughout their lives (though litters tend to be smaller with old cats). In consequence, cat colonies tend to remain at the size of the available food supply, since for every cat shot, poisoned, trapped, or even killed with a crossbow (something which is apparently becoming more common) there is another litter of kittens which would otherwise have starved waiting to step into the paw-prints of their murdered cousins.
In consequence, some communities are realizing that the best way of controlling the size of cat colonies is to leave it up to the colony members themselves. Cats are territorial beasts, and will keep outsiders out of their territory. If those cats have been trapped, neutered and returned to their colony,(a process known as TNR) they become effective immigration officers for the neighbourhood.
Colonies of such cats can become a local feature, such as the cats of Parliament Hill in Canada and the Colosseum cats of Rome. Volunteers make sure that the cats are given worming powder in their food, and have their bedding areas dusted with flea powder. Vets who neuter the cats often anesthetize and cut off the tip of an ear so they know which cats they need not bother trapping again. In many areas where cats are not a threat to the local wildlife, having a managed feral colony seems to be the best solution. Some cat charities, such as SNIP have been established for just this purpose. (SNIP was originally formed as the Society to Neuter Islington's Pussies, but its reach has since extended further.) However, feral cats are such prolific breeders that it has been estimated that about 75% of a colony has to be sterilized before the population stabilizes.
What is the life of a feral cat like?
It depends on the environment. This means both whether the vegetation and weather are suitable and how well the cats are tolerated by the human population (British holiday-makers in Spain often infuriate the natives by leaving food for feral cats). The idea that the life of a feral cat is one of unadulterated misery has developed partly because feral cats generally revert to being nocturnal; so a feral cat out in daytime may already have a problem. Injured, old or very ill cats are less effective at avoiding humans, so these are the ones which are seen more often. Most feral cats live alone, begging their food, hunting what they can and raiding the rest from domestic pets and rubbish bins. Many of these cats interact socially with domestic cats, to the extent where a genetic survey of cats in one English town established that the paternity of a large percentage of the town's kittens was probably due to feral toms.
However, those charities which actively monitor feral colonies report that though many feral cats live two years or less, some feral cats live into their teens, and even a 26-year-old has been reported. That some feral cats live so long is less because the life of a feral cat is easy than because cats are much tougher and resilient than the bone-idle sack of fur on your sofa would have you believe. There are cases of feral cats which have lost a leg to traps put out by landowners but then have gone on to live for years, sometimes raising a few litters of kittens along the way.
Can feral cats readjust to life as pets?
It is becoming increasingly recognized that feral cats should be regarded as wild animals, rather than domestic pets gone bad. As with all wild animals, attempts at taming them have had mixed results at best. Cats born wild seldom adjust to domestication after their first year. In fact, unless adoption into a human household is done within a month or two of birth, many attempts to domesticate a feral kitten will fail - which is perhaps unsurprising, as feral cats seldom see humanity at its most attractive.
Nevertheless, there are many cases of older feral cats which have been adopted after first going through a transition period in a rescue shelter, and which have then settled down to happy lives as domestic cats. Such cats are unfortunately an exception, and animal lovers working at rescue centres have the heartbreaking job of killing a large proportion of the feral cats which are brought to them.