How large is a cat's territory?

The wild counterpart of the domestic cat has a huge territory, with males patrolling up to 175 acres. Domestic cats which have gone wild and are living in remote areas where there is unlimited space also cover impressively large areas. Typical farm cats use nearly as much space, the males ranging over 150 acres. Female farm cats are more modest, using only about fifteen acres on average. In cities, towns and suburbs, the cat population becomes almost as overcrowded as that of the human citizens. The territories of urban cats shrink to a mere fraction of the home range enjoyed by their country cousins. It has been estimated that cats living rough in London, for example, enjoy only about one-fifth of an acre each. Pampered pet cats living in their owners' houses may be even more restricted, depending on the size of the gardens attached to the houses. The maximum density recorded is one pet cat per one-fiftieth of an acre.

This degree of variation in the size of feline territories shows just how flexible the cat can be. Like people, it can adjust to a massive shrinkage of its home ground without undue suffering. From the above figures it is easy to calculate that 8,750 crowded pet cats could be fitted into the territory of one wild cat living in a remote part of the world. The fact that the social life of the crowded cats does not become chaotic and vicious is a testimony to the social tolerance of cats. In a way this is surprising, because people often speak of the sociability of dogs, but stress that cats are much more solitary and unsociable. They may be so by choice, but given the challenge of living whisker-by-tail with other cats, they manage remarkably well.

They achieve this high-density success in a number of ways. The most important factor is the provision of food by their owners. This removes the need for lengthy daily hunting trips. It may not remove the urge to set off on such trips – a well-fed cat remains a hunting cat – but it does reduce the determination born of an empty stomach.

If they find themselves invading neighbouring territories, they can give up the hunt without starving. If restricting their hunting activities to their own cramped home ranges makes them inefficient prey-catchers, it might prove frustrating, but it does not lead to starvation and death. It has been demonstrated that the more food the cats are given by their owners, the smaller their urban territories become.

Another factor helping them is the way in which their human owners divide up their own territories – with fences and hedges and walls to demarcate their gardens. These provide natural boundary-lines that are easy to recognize and defend. In addition there is a permissible degree of overlapping in feline territories. Female cats often have special areas where several of their home ranges overlap and where they can meet on neutral ground. The males – whose territories are always about ten times the size of those of the females, regardless of how great or small the crowding – show much more overlap. Each male will roam about on an area that takes in several female territories, enabling him to keep a permanent check on which particular queen (female) is on heat at any particular moment.

The overlapping is permitted because the cats are usually able to avoid one another as they patrol the landmarks in their patch of land. If, by accident, two of them do happen to meet up unexpectedly, they may threaten one another or simply keep out of one another's way, watching each other's movements and waiting their turn to visit a particular zone of the territory.

The numbers of pet cats are, of course, controlled by their owners, with the neutering of adults, destruction of unwanted litters and the selling or giving away of surplus kittens. But how does the territorial arrangement of feral cats survive the inevitable production of offspring? One detailed study of dockland cats at a large port revealed that in an area of110 acres there were ninety-five cats. Each year they produced about 400 kittens between them. This is a high figure of about ten per female, which must mean that on average each queen gave birth to two litters. In theory this would mean a fivefold increase in the population each year. In practice it was found that the population remained remarkably stable from one year to the next.

The cats had established an appropriate territory size for the feral, dockland world in which they lived, and then kept to it. Closer investigation revealed that only one in eight of the kittens survived to become adults. These fifty additions to the population each year were balanced by fifty deaths among the older cats. The main cause of death here (as with most urban cat populations) was the fatal road accident.