Tilly Blyth

Jake, aged eight months.

Under natural and semi-natural conditions, cats will form strong social relationships with familiar individuals, usually close kin. From an early age, the mother is recognised and greatly preferred to unfamiliar females. The young also recognise other adults in their own group and readily accept care from them. In groups of feral cats and those reared in large outdoor enclosures, the kittens are often allowed to suckle from females other than their own mother. Social relationships such as these, which depend so much on familiarity, are most readily formed in the first two months after birth in domestic cats. When the process by which strong social attachments are formed was first described in precocious birds, it was called 'imprinting' because it happens quickly and leaves a long-lasting effect on social preferences. Cats are much less well developed at birth and form social attachments more slowly than do geese or ducklings.

Humans and members of other species may also be incorporated into the social group and responded to with affection if they were encountered by the cat when it was young. Despite a basic ability to respond socially towards people, adult cats and kittens show considerable individual variation in their friendliness towards humans, whether familiar or unfamiliar, and even kittens from the same litter can differ considerably in their friendliness.

onship is crucial to the kitten's development, particularly in view of the domestic cat's relatively slow development and long period of dependence on maternal care. From the outset, interactions between mother and kittens regulate suckling. During the first three weeks after birth, the mother initiates suckling by approaching her kittens and adopting a characteristic nursing posture in which her nipples are easily accessible. At this stage, kittens can orient towards the nest, using olfactory and, to a lesser extent, thermal cues. Nest orientation starts to decline during the third week, following eye-opening and the development of visually guided behaviour.

Kittens will suckle from a non-lactating female in the same way as from a lactating female until about three weeks of age, which means that a milk reward is not necessary for either initiation or maintenance of suckling. After three weeks of age, an absence of milk reward leads to a reduction in the duration of suckling, although the frequency with which suckling is initiated remains unaffected. In the absence of their mother, kittens of 12 weeks will suckle from the teats of intact adult males. Clearly, suckling is a rewarding activity in its own right, irrespective of whether the kitten obtains milk from so doing.

Later, as the kittens become more mobile, they become increasingly responsible for approaching the mother and initiating suckling. In the later stages of the weaning period, towards the end of the second month, the kittens become almost wholly responsible for initiating suckling and the mother may actively impede their efforts by blocking access to her nipples or by removing herself from the kittens' proximity. The increasing role of the kitten in initiating suckling develops in close parallel to the kitten's improving sensory and motor abilities.

Kittens which have been reared since birth on an artificial brooder are perfectly capable of suckling from a brooder nipple, but fail to suckle when given access to a lactating female because they show inappropriate social responses to her. Kittens which are artificially separated from their mother much earlier than normal (at two weeks of age) subsequently develop a variety of behavioural, emotional and physical abnormalities. They become unusually fearful and aggressive towards other cats and people, show large amounts of random undirected locomotor activity, and learn less well. Some develop asthma-like respiratory disorders.

Tara Montgomery

Zoe (10 weeks) and Zelda (14 weeks) acquiring predator skills.

Predatory behaviour
The importance of social relationships in the behavioural development of cats is perhaps best seen in the development of predatory behaviour. Under natural conditions, cat mothers gradually introduce their young to prey, providing them with a series of situations in which their developing predatory skills can be expressed. Early on, the mother will bring dead prey to her young; later she will bring live prey and release the prey near the kittens, intervening only if the kitten starts to lose control. Rather than 'teaching' her kittens to catch prey, the mother creates situations in which their own responses will lead them to learn to acquire behaviour that serves to increase their chances of survival and reproducing successfully. The predatory behaviour of cat mothers is beautifully meshed with the improving capabilities of their developing kittens and, as their predatory behaviour develops, so her role declines. In the short term, the mother's responses to prey which she has brought back to the nest are finely tuned to her kittens' responses. The longer the kittens pause before interacting with the prey, the more likely the mother is to attack the prey, for example. Kittens show increased rates of predatory behaviour in the presence of their mother, and the mother's behaviour tends to lead the kittens to interact with prey. When dealing with live prey, laboratory studies suggest that kittens tend to follow their mother's choice. For example, Kuo ('The genesis of the cat's response to the rat,' in Journal of Comparative Psychology, vol. 11, pp. 1-35,1930) found that kittens usually killed the same strain of rat that they had seen their mother kill.

Social experience when young plays an important role in determining the range of stimuli eliciting predatory, as opposed to social or fearful, behaviour. In a pioneering set of experiments, Kuo (1930) raised kittens and rats together in the same cages. Kittens raised with rats never killed rats of the same strain when they grew up, although some would kill rats of a different appearance. The implication of Kuo's results was that kittens whose social companions during early life were rats formed social attachments to rats, inhibiting later predatory responses to them. However, when given the opportunity to form social attachments to other kittens as well as rats, other kittens were preferred. Kittens raised both with siblings and rats formed clear social attachments to their siblings. Nonetheless, these kittens did show a distinct tolerance of rats and a reduced predatory response towards them, although some eventually became rat-killers (Kuo, Z.Y., 'Further study on the behavior of the cat toward the rat', in Journal of Comparative Psychology, vol. 25, pp.1-8, 1938).

New foods
Willingness to try new foods, and preferences for particular types of food also appear to be strongly influenced by the mother. Wyrwicka & Long ('Observations on the initiation of eating of new food by weanling kittens,' in Pavlovian Journal of Biological Science, vol. 15 pp. 115-22, 1980) reported that laboratory kittens which were presented daily with a novel food, tuna or cereal, whilst their mother was present started to eat the new food on the first or second day of exposure. However, kittens which were presented with the novel food whilst on their own did not start to eat it until about the fifth day of exposure. The readiness of a kitten to take novel food is, of course, likely to depend on how long it has been deprived of food as well as on the range of its previous experience.

Wyrwicka ('Imitation of mother's inappropriate food preference in weanling kittens,' in Pavlovian Journal of Biological Science, vol. 13 pp. 55-72, 1978) trained mother cats to eat banana or mashed potato. She then tested their kittens' food choice. When offered a normally preferred food (meat pellets) and an unusual food (banana or mashed potato), most of the kittens followed the example of their mother and ate the unusual food rather than the meat pellets. The kittens' preference for the unusual food persisted even when they were tested on their own. The kittens started to share their mother's food choices soon after weaning commenced (at about five weeks of age), and the effect was most marked towards the end of the weaning period (7-8 weeks).

Social learning
Young cats are well adapted to learning from their mother, and show a strong interest in, and ability to learn from, the behaviour of other cats. This general phenomenon, of being able to benefit from observing a conspecific's experiences, is found in many species and is referred to as social learning. Kittens usually kill the type of rat they have seen their mother kill when young (Kuo, 1930).

Chesler ('Maternal influence in learning by observation in kittens,' in Science vol. 166 pp. 901-3, 1969) found that kittens which were allowed to watch their mother perform an operant response (pressing a lever to obtain food) were able to acquire the response quickly, whereas kittens who were given the opportunity to acquire the response by trial-and-error never did so. Moreover, kittens who watched their own mother acquired the response sooner than kittens who observed a strange female, suggesting that social learning is facilitated if the 'model' cat is familiar to the observer.

Adult cats also show social learning. Anecdotal observations of cats letting themselves out of rooms by jumping up at door handles might be explained as simple trial-and-error learning when the door handle is a lever since their response is rewarded by release from the room. However, such an explanation is much less plausible when the handle is a knob which the cat cannot turn and, therefore, its response cannot be rewarded. In such cases, it seems more likely that the cat has observed the actions of humans leaving the room. Systematic experiments have demonstrated that cats can acquire some learned responses faster by observing another cat perform them than by conventional conditioning procedures. Observing another cat acquire the response is important, and has a more beneficial effect than watching another cat perform a skilled response that has already been learned.

The mother is, of course, not the only source of social experience during a kitten's development, and increasing evidence indicates that siblings play an important role in social development. During the early suckling period, for example, competition between littermates for access to nipples can be an important regulator of suckling. Kittens establish distinct and consistent preferences for suckling from a particular teat during the first few days. The establishment of teat preference is one of the earliest forms of learning shown by kittens.

Social experience with siblings also seems to play at least a facilitating role in the development of later social skills. Kittens which have been reared on an artificial brooder, with no experience of siblings when young, do eventually form social attachments, but are generally slower to learn social skills than normally-reared kittens. Brooder-reared kittens do not appear to form substitute social attachments to their brooder. However, the mother may provide a substitute source of social experience for single kittens raised without littermates. She plays much more when she has a single kitten than she does when she has two kittens which play with each other. She acts as a substitute sibling. The presence of siblings encourages young kittens to interact with prey. Caro ('Predatory behaviour in domestic cat mothers,' in Behaviour vol. 74 pp. 128-48, 1980) found that pre-weaning kittens were more likely to watch prey if their siblings were also watching the prey. Social experience with littermates is, therefore, yet another factor influencing behavioural development.