Feline Territorial Behaviour

Territory The size of the territorial range of cats (home range) varies between feral and pet cats, male and female cats and neutered and entire cats. Although evidence regarding the absolute size of home ranges is inconsistent between studies performed in different countries and habitats, intact male home ranges are, on average, three times larger than intact female home ranges (Liberg et al., 2000). The same author found that pet females in Sweden had home ranges of around 30-40 hectares and rarely roamed further than 600m from their homes (Liberg, 1980), and feral females had home ranges that were about four times larger than those of pet females (Liberg, 1984). It appears that male home range size is determined by the availability of reproductive opportunities, whilst that of females is governed by the availability of food. Range size has been found to vary between 0.1 hectare in a Japanese fishing village to 170 hectares in the Australian bush (Bradshaw, 1992), indicating that cats do not have a specific need to maintain a large territory, only to hold sufficient territory to satisfy specific survival needs. A larger territory will also be needed if suitable resting sites are distant from hunting locations.

The home ranges of neutered male and female domestic pet cats are likely to be smaller than their feral counterparts, and in one UK study were found to be 0.45 and 0.27 hectares respectively (Bradshaw, 1992). This reflects the high-density food resources, the close proximity of hunting, resting and latrine locations, and competition for space between the numerous cats in a typical suburban area. Home range size is inversely proportional to population density (Bradshaw, 1992).

Within the home range, the cat will also have a smaller core territory that is primarily used as a secure site for resting, feeding, and self-maintenance behaviour. In wild cats this core territory is typically around 100m in diameter and makes up 0.2 to 4% of the total home range (Turner & Bateson, 1986). This core territory is away from direct view or intrusion by other cats that are not part of the social group.

The extent to which female cats will defend their home range relates to the abundance of food resources. Studies by Foley et al (2005) and Driscoll et al (2009) indicate that cats defended their territories, whilst a study by Corbett (1979) identified a lack of competition between cats due to the reliable excess of food in the abandoned farms on the Scottish islands where the study took place.

Conflict is avoided by the use of scent marks and cats following strict timetables for their movements around their territories. Urine spray marks provide a signal between cats that a particular area is likely to be in use by different individuals at certain times of day. The degradation of a urine mark over time provides other cats with an indication of when the depositor was last in that location. With regular re-marking, this provides cats with a geographical and temporal map that enables them to pass through an area without encountering one another. Claw marks are used to indicate firmer territorial boundaries that discourage the presence of non-resident cats.

Apart from providing other cats with information about ownership and usage of territory, scent marks also convey information about the identity of the depositor, its sex, health and reproductive status. This enables more complex social organisation than merely avoidance, with cats choosing to avoid an area or attempt to gain control of it, depending on the threat posed by the current resident and the need to gain access to the resources included in that area.

Facial and flank marks are deposited in core territory where a cat does not anticipate meeting unfamiliar cats. In areas where facial and flank marks are left, other forms of marking (spraying and clawing) are reduced or absent.

Scent marks are not only a signal to other cats, but also carry meaning for the depositor. In the core territory, cats are more likely to be in a parasympathetic sate of arousal, in preparation for activities such as resting, feeding and grooming. Outside the core territory, some degree of sympathetic arousal is always required, as the individual is either vulnerable or engaged in hunting. Facial and flank marks may provide a chemical signal to the cat that favours a parasympathetic state in all individuals that are present, reducing the likelihood of conflict in colonies where several cats share a common core territory.

The natural organisation of territory in cats poses some problems for domestic pet cats.

In a domestic setting, the difference in area between the home range and core territory may be minimal, and for indoor-only cats that have a view of a garden, the boundaries of the indoor space are the absolute limits of territory, leaving no opportunity for conventional territorial organisation or distance maintenance from neighbourhood cats that are easily visible from indoors.

In urban areas the density of cat populations may be high, exceeding 50 cats per square kilometre. In a study by the author, 81% of 734 UK cat owners whose cats were allowed outdoor access indicated that their neighbours also had at least one cat that was allowed outside, and 66% reported seeing a neighbour’s cat in their garden at least once a week. Owner reports of the number of different cats regularly seen in the garden and the frequency of cats visiting the garden were both correlated significantly with the frequency of injuries due to conflict with non-resident cats.

Forty-one percent of those households reported some level of home entry by neighbourhood cats, with 18.7% reporting that cats came in to fight with their cat and 25.6% reporting that cats came in to steal food. For households that had a plain cat door without security features (as opposed to a selective entry cat door that only allows resident cats in and out) the figures were significantly higher; 24.8% of cat owning households reported that neighbourhood cats came into their home to fight with their cats, and 39.4% reported that cats came in to steal food.

Given that the territorial marking behaviour of cats has evolved to reduce direct conflict, and maintain distance, it is worrying that so many domestic pet cats regularly experience home invasions and injuries from fights with non-resident cats. This ought to be a significant source of stress for domestic pet cats. The fact that cats commonly take the risk of entering each other’s core territory in order to get access to food indicates that there are serious problems with the way that pet cats are being kept.

Cats that had experienced injuries due to conflict with other cats showed 3.9 times that rate of indoor spray marking compared with cats that had not experienced injuries. They also waited by the cat door before going out, and became agitated and afraid when they saw another cat in the garden.

There was a strong, and significant, correlation between cats entering the home for food, and fighting with resident cats in the home. Only 45% of owners in the survey fed their cats ad libitum, indicating that a lack of availability of food may be a strong motivation for many cats to enter homes seeking sources of food, and thereby ending up in conflict with residents.

Cats who had experienced home invasion of any kind showed 24% higher levels of scratching behaviour compared with cats that had not experienced home invasion. They also waited by the cat door before going out, became agitated and fearful when they saw other cats in the garden, and showed significantly higher rates of hair loss and skin disease.

Domestic gardens also often lack suitable landmarks for scent marking, such as posts for scratching. As a result, the boundaries between the necessarily small territories of domestic cats become blurred. There are few clear indicators of territory ownership to deter a cat from approaching another cat’s home.

Forty-one percent of cat owners that gave their cats outdoor access did not provide a cat door. So, these cats are reliant on a person to let them in and out of the house. Cats follow a strict timetable of movement around their territories so that they can avoid contact with other. By being tied to the owner’s routine, the cat is unable to follow this kind of pattern.

However, even though outdoor access is fraught with problems due to a lack of owner understanding of the actual needs of cats, there is evidence that a lack of outdoor access contributes to problem behaviour. Heidenberger (1997) found that cats that were allowed to go outside when they wanted, or at least 2-3 times weekly, were less problematical to their owners.

Key points: • The size and layout of a cat’s territory is adapted to the availability of resources, such as food. • Cats will choose to occupy small territories if food resources are sufficient. • In the UK, suburban environments often have a high cat population density and a lack of suitable marking locations, so that territorial boundaries become blurred and unclear. • Since many cats are not fed ad lib, their need for food may drive them to investigate and invade the core territories of other cats.