The Behaviour of the Meerkat, Stcricata suricatta (Schreber)

By R. F. Ewv.i<’)

With 20 Figures Received 27. 2. 1963

“. . . in biology, to see things as a whole is to recognise on the one hand that there is no limit to the physical and chemical investigation of living mechanisms, and yet, on the other hand, no limit to their biological synthesis into the complete and intelligent, the wonderful and beautiful, living creature.”

A. V. HILL

Contents: Introduction p. 570. - General habits and mode of life p. 571. - Language p. 572. - Gaits and postures p. 574. - Behavioural heat regulation p. 576. - Toilet behaviour and comfort movements p. 577. - Micturition, defaecation and marking p. 579. - Food cap- ture and feeding p. 580. - Attack and defence p. 583. - Sexual behaviour p. 587. - Repro- duction and parent-young relationships p. 588. - Play p. 597. - Following p. 597. - Miscellaneous p. 598. - General intelligence and learning abilities p. 599. - Discussion p. 600. - Summary p. 605. - Zusarnmenfassung p. 606. - Acknowledgments p. 606. - References p. 606.

Introduction

There has, in the immediate past, been a tendency to believe that while species specific patterns form a major component of the behaviour of other vertebrates, they are relatively unimportant in mammals, or that their study in mammals is not likely to be rewarding, since learning so complicates the picture as to make fixed action patterns very difficult to recognise. Two fac- tors seem to have been mainly responsible for this attitude. Firstly, it is not always easy to keep wild mammals in conditions of sufficient freedom to allow them to display their fu l l complement of patterns; secondly, familiarity with domestic species has tended to blunt rather than to sharpen, awareness of patterned behaviour. O n the one hand, a pattern may be so familiar that it is accepted almost unnoticed and, on the other, the average cat or dog owner devotes more attention to training the animal to behave in a domesti- cally convenient manner than he does to observing its natural habits. It is therefore no wonder that it is the learning capacities of mammals, rather than their endogenous patterns that impress him. If, however, a wild mammal can be kept in domestic conditions, given the maximum possible freedom and observed over a long period, then the wealth of species specific patterns that can be seen is truly surprising. This is particularly true of carnivores, for here the behavioural repertoire is exceedingly rich and varied. This is to be expected since, being killers, their patterns of food capture and of attack and defence will be complex. Since prey killing is not possible for the very young, the

and because he also thought these animals wonderful and beautiful. 1) For Dr . KONRAD LORENZ, on his 60th birthday, as a token of admiration and respect

The Behaviour of thc Mcerkat, Suricata suricatta (Schreber) 571

period of dependence on the parents must be relatively prolonged and paren- tal bchaviour well developed. In the case of social carnivores, patterns whose function is to prevent mutual destruction must also be present.

The prescnt study is purely descriptive: an attempt has been made to catalogue as fully as Fossible the characteristic patterns of a single species and to understand thcir role i n the normal life of the animals in natural conditions. The observations were made on two females, Fa and Fb, caught a t difierent times when each was only a few weeks old, on a male, M, obtained at the age of approximately nine months from a zoo, where he had been in captivity for soinc months, and on two litters of young born in the home.

The animals were kept as domestic pets, having the free run of the house whilc I was at home and at other times being confined on an open veranda. They very casily became used to a lead and were reqularly taken out for walks. This made it possible to observe their normal foraging for food and their behnviour towards other species and in a variety of situations, natural and unnatural.

Fa was ltept alone unt i l she was P//J years old, when M was obtained as a mate for her : the litter of young; were born a few months later. Approxima- tely a year aftcr the advent of the male. Fa died as the result of a road acci- dent and was replaced shortly after by Fb. H e r first litter was born when Fb was a little over a year old. At the time of writing M is approximately 3 years and Fb about 18 months old. In addition a few observations have been made on another femalc, Fc, also captured at a few weeks old. This animal belongs to a colleague and is ltept a t t h e laboratory.

This paper had already been written when DUCKER’S (1962) study of Sr,iuicutn appeared. Apart from noting a few points of difference I have thought i t best to make no alterations, for the two studies are largely com- p!enientary. DUCKER’S main concern is with the ontog;eny of behaviour, mine with its cthological and biological interpretation. While this may, to some ex- tent, reflect our differing; interests, it is also conditioned by the different circumstances in which the observations were made. DUCKER’S animals were caged and i n a foreign land, while mine were in their home ranqe and had considerable freedom: the resulting; contributions to our knowledge of the behaviour of a single species reflect the different types of information that can be acquircd by the two methods of study and are therefore of some interest from the point of view of comparative niethodology. Since the number of individuals studicd is st i l l very small it is not always possible to decide how far the few pointc in which our observations are not in agreement reflect individual variability and how far they are correlated with the different env i ron ni en t a I situations .

General habits and mode of life

Sur icntn suricnttn (Schrcbcr), one of the comnionest small cnrnivorcs of South Africa, belongs to the family Viverridac, subfamily Herpestinac. The common name, niccrkat, dcrivcs from the somcwhat monkev-likc face, with l a r x eyes and reduced pinnac on the cars. Mccrkats arc hiqhly soc;al and livc in communities. frequently to:cther with the ground squirrcl. Gcocciirrus inauris (Zimm.). Suricuta has long claws on thc fore feet and is certainly capnblc of diz$iiig its own burrows, but in mixed communities sccins to leave most of thc work of cxcnvation to the squirrels, taking posscssion of as much of the burrow system as required. Tlic squirrels give ground to thc mccrliats without a fiB1it and the latter behave as though the squirrels were invisible to them. Mcerkats vcry readily become tame, and this scenis to be rclntcd to their social habits (together with the fact that they are extremely pugnacious 2nd not easily frightened). Thc need for social contact is so great that in the absence of their fellows a human substitute companion is very readily accepted. Thcy bccomc extremely attached to the people they know, but are oRcn liable to attack strangers.

572 R. F. EWER

This also relates to their natural life, for while they live communally, strangc conspecifics are not accepted a t once, but are attacked, and driven of€. Another habit shown in domcstica- tion which is related to their natural habit of living communally in burrows is the fact that meerkats like to creep into their owner’s clothing, u p a trouser leg or inside a shirt or jersey. I n this behaviour social contact as well as physical contact with the burrow wall substitute is probably important.

Suricutu is entirely diurnal: meerkats emerge from their burrows shortly after sunrise and retire to them to sleep at dusk. I have made no direct measurements of sensory acuity, but numerous observations allow a rough comparison with human capabilities. Meerkats are predominantly visual animals. In bright light vision is acute and form recognition is of the same order as human capability in this respect. A dog is recognised from some hun- dreds of yards away and a hawk is noticed at a height where i t appears to the human eye as a small speck. O n the other hand, at low intensities of illumination vision is poor and an insect is easily lost sight of in dim light. The behaviour suggests that the retina may be a pure cone one. The sense of smell is also acute and the nose is used extensively during foraging for insects. When I have handled Fc a t the laboratory the male reacts to her smell on my clothing when I come home and meerkats can at once detect by smell the place where a strange person has been sitting. Out of doors, dog faeces, even when not very fresh, are carefully sniffed a t and the alarm call is given a t low inten- sity, but cow dung, even if fresh and highly odorous, is passed over without comment. Hearing is no more acute than in man and sound location is ex- tremely poor, presumably the result of the combination of reduced pinnae and small inter-aural distance.

In domestic conditions the fact that meerkats are predominantly visual animals is very clearly shown. They will take up any position of vantage offering a wide field of view, such as a window sill and be content there for long periods watching all that goes on outside. The fact that it constitutes such a good lookout post is also one of the reasons why they like to climb on one’s shoulder.

Language

Meerltats make a variety of sounds and vocal communication plays an important part in social life. The newborn young make small bird-like cries practically all the time they are awake. Similar “nest-chirping” is recorded by DUCKER (1957) in young genets and by HERTER (1952) and HERTER 8r OHM-KETTNER (1953) in young polecats and martens. This constant vocalisa- tion gradually diminishes and more differentiated cries corresponding to spe- cific situations develop during the first few months. It was noticeable that the two females studied remained much more noisy than the male. In them, almost any activity tended to be accompanied by little “conversational noises“, human sounds. Distinctive sounds are made in the following situations:

Most of the sounds are made with the mouth closed. Thus they have no distinct initial consonant and are extremely difficult to describe or equate with whereas the adult male is silent except in certain definite situations.

A g g r e s s i v e o r m i x e d t h r e a t . An enemy, such as a dog, is threatened with growls and, if i t approaches sufficiently closely, by violent explosive spitting. These sounds accompany postures and movements charac- terised by a combination of conflicting tendencies to attack and to refrain from doing so. In intraspecific encounters growling is sometimes used when defending the food against possible theft.

The Behaviour of the Meerkat, Suricata suricatta (Schreber) 573

D e f e t i s i v e t h r e a t. This is a sharp, rapidly repeated, violent clucking noise. No human observer hearing it for the first time would have any doubt about its significance: it is a “cross noise” in any language. Its de- fensive character is shown by the fact that while it is being made there is very little tendcncy to deliver a serious bite and that it is the normal accompani- ment of the purely defensive belly-up posture to be described later. It is used if the animal is picked up against i ts will, by the mother if the young attcmpt to obtain milk from her when she is not prepared to suckle them ot if onc adult disturbs another. I have never heard this noise used in serious threat against a genuine enemy, but I believe that this is because I have never seen a gcnuine enemy press an attack home to the point where the meerkat abandons offensive or mixed threatening behaviour and is forced to its last line of defence, the belly-up posture. If this occurred i n an encounter with an enemy, i t is virtually certain that i t would be accompanied by the defensive threat cry.

F e e d i n g. Little “wurruck-wurruck” sounds and grunts of satisfaction accompany feeding. This noise also is easily comprehensible to the human ear as signifying “lovely grub”. The domestic cats learned its significance and the sound made by the litter of young eating would quickly bring them to the scene of activity to share the meal.

D a n g e r W a r n i n g. Anxiety is expressed by a clear drawn out note. At higher intensity this becomes the fear note, which serves as a warning cry. As danger becomes more imminent, the cry becomes louder and more rapidly repeated. The note evoked by an aerial predator is, however, different from the sound made i n response to a terrestrial enemy. For the aerial predator it is a drawn out “wauuk - wuauk”, a clear liquid note: for the ground predator the sound is more abrupt and gruffer. I believe that this difference in the cry reflects differences in the animal’s general behaviour i n the two situations. A tendency to attack is always present with a ground predator, and the gruff- ness of the warning note reflects fear mixed with aggression. There is, how- ever, no possibility of attacking a distant aerial predator and such an enemy is not normally threatened: the “hawk-warning” is thus the purc undiluted fear sound. I have, however, once heard Fb growl at a hawk. This was an occasion when she was in the garden accompanied by her young. I n response to her warning the young had gathered close beside her and the hawk then came closer. Fb gathered her young under her, gazed up at the hawk and growled.

G e n e r a 1 i s e d a 1 a r ni b a r k i n g. A repetitive short sharp bark expresses a sort of general defiance. A very similar short yelping bark is used by the young, aRer the stage when they have left the nest, as a distress call if one is left alone, but in the adults the cry has almost always been heard in response to certain types of auditory stimuli. The male barks in this way in response to the sound of Fb making the “cross noise” at high intensity; if there is an outburst of barking amongst the dogs of the neighbourhood this may also set him barking. I have not been able to find out whether the barking of one meerkat will cause another to follow suit, but this seems very likely. Cer- tain types of unnatural noise may also evoke alarm barking; for instance Fa would respond in this way to the sound of a typewriter or an egg-beater in usc and at the agc of 6 months Fc started to bark in response to the typewriter. I have once heard this type of barking in response to a visual stimulus. This was when Fb, from a window sill lookout post had seen a dog enter the gar- den. She returned to her young giving the alarm call very loudly and was clearly in a state of indecision as to the safest place to take them. She thcn gave a brief burst of alarm barking before quieting down.

574 R. F. EWER

A characteristic of alarm barking is that it is not usually directed towards the source of the sound, but at the same time it is not undirected. Its orienta- tion can best be described by saying that it is directed “outwards”. T ~ L I S a meerkat may sit on the desk beside the typewriter which is evoking barking, but the animal barks towards the window; similarly the male, if he is 011 my shoulder will sit erect and bark his defiance to the world in general.

It thus seems liltely that in natural conditions this cry serves as a general alerting call to the entire colony and that if one animal starts barking the alarm will spread rapidly, exactly as is the case with barking dogs.

S e t t 1 i n g d o w n. The females, when settling to sleep, frequently make a little clear plaintive cry, repeated with a inarlted diminuendo and gradually fading out.

D i s s a t i s f a c t i o n. The male makes a curious low crow-like cawing sound when he is dissatisfied. Frequently this cry is used as a signal to a human companion indicating that action should be taken to set things right: for instance, he will sit at one’s feet crowing as a sign that one is i n a position malting it impossible for him to climb on one’s lap. I have not heard any of the females make this sound and it remains uncertain whether it is a natural call or has been produced as a result of the U I I L I S L I ~ ~ relationship with human companions.

One curious point that has been noted repeatedly is that no cry of pain is made. Although paws and tails have often been trodden on and feet caught i n doors, in a way which would certainly cause vocalisation in any dog or cat, a meerltat makes no sound at all. This has been found to be true of all the four individuals known to me. VOSSELEII (1928) notes that the same is true of Nan- dinia binotata (Gray).

Gaits and postures

As in most herpestines, the body is long and low and the legs short. The pelvis is broad and strone and the shoulders narrow. The hind legs are thus rather widely spread. which gives the animal a rather clumsy gait, whether walking or running. The shortness of the legs makes trotting a very inefficient nieaiis of progression and it is very little used, avpearing only briefly duritig the transition from wallting to the canter or gallop used when greater speed is required. On flat ground, the body remains low at all speeds, but when galloping through long grass the animal bounds high in the air so as to increase its ranqe of vision. The gallop is of the normal carnivore type, with the back arched after the hind feet have left the ground so that the latter are set down again slightly in advance of the fore paws. Even a t fu l l g a l l ~ p how- ever, meerkats cannot attain much speed and are easily overtaken by c~ human runner. Although locomotion is digitigrade, the whole lower sur fx . of the pes is covered by a thickened hairless foot pad. This is utilised in the sitting up posture which is very frequently adopted.

When they are young, ineerkats are moderately good at jumping, but as they attain their fu l l weight, they become less adept at this. The claws are not adapted for tree climbing, but by means of them the animal can pull itself up onto any ledge which offers a suitable grip; wire netting, for instance, is easily scaled in this way and Fa frequently climbed up slatted wooden shutters. Adults will not jump down from a height of more than about half a meter, and do not turn round to climb down but descend backwards.

L o w s i t. In this posture (Fig. 1) the animal supports itself on the whole plantar surface of the pes. The tail is stretched out behind and the back is held vertically with a slight concavity just above the pelvis. In this position

The Behaviour of the Meerkat, Suricata suricatta (Schrcbcr) 575

f i g . 1; Low sir posture. n) adul t male, in front of fire. b) female, aged 5 weeks. This and all the following tracings from cin6 films taken a t 17 framesiscc.

the animal is extremely stable and may remain for a con- siderable time. Low sit is used both as a lookout posture and i n sun-basking when the sun is low, particularly in the early morning. I n domestic conditions low sit is frequently adopted in front of an electric fire.

I3 i g h s i t. In this posture the animal rises on its hind feet so that only the digits arc in contact with the ground (Fig. 2). The tail is held rigidly against the ground to give extra support and the wholc body extended vertically as fully as possible. This is mainly a lookout posture, giving

Fig. 2: High sit posture. Adult male

Fig . 3: Adult male and three young (7 weeks) basking in front of a fire: the young are showine hirh sit.

0 --- - - - >

low sic and hearth rugging postures

576 R. F. EWER

maximum visual range, and is not much used in basking. Positions interme- diate between low sit and high sit with maximal vertical extension may also occur but are not maintained for l m g (Fig. 3).

L a z y s i t. This is a posture (Fig. 4) less frequently seen than the two previous ones. It is used as a sort of intermediate, when the animal is resting, but sufficiently alert not to sleep. It has often been seen in the two females,

Fig. 4 : Adult female Fb in lazy sit posture

but very rarely in the male. The animal sits on its hind quarters, with the tail turned forwards between the hind legs and the body held rather loosely in a somewhat slouching manner. It is used only when the animal is quite at ease and is not watching its surroundings with great attention.

S 1 e e p i n g p o s t LI r e . In the normal sIeeping posture of a single individual (Fig. 5) the animal sits on the hind feet, with the tail directed for- wards. The head is bent down and tucked under the body with the top of the head resting on the ground between the hind feet. The paws are flexed at the wrist and laid alongside the snout, between the hind feet. This is clearly a position in which heat loss is minimised. The animals normally sleep together in groups and a second will curl itself over the first, and a third add itself to the pile, always with the ventral surface covered. In warm situations, how- ever, such as in front of a fire, the animals may sleep in a variety of positions, lying stretched out on the belly, back or side.

Fig. 5: Sleeping posture (adult nialc)

Behavioural heat regulation

A number of distinctive patterns serve to facilitate either warming or cooling, according to the circumstances. Since the hair on the belly is much sparser than on the back, heat exchange occurs most readily in this area and the heat regulatory postures all concern the relation of the ventral surface to the environment.

(1) W a r m i n g. Warming is achieved by maximal exposure of the ven- tral surface to a heat source. In the early morning sun, or in front of a fire, this is done by adopting the low sit posture, with the belly towards the source of warmth. When the sun is high, or if the fire has a downward throw, the animal may lie flat on its back, or slightly on one side, with the legs spread (Fig. 6a). If the floor in front of the fire has become warm the animal may indulge in “hearth-rugging” (b). In this posture the meerkat lies on its belly, with the body flattened, the hind legs spread sideways and the fore paws

The Rchaviour of thc Mccrkat, Suricata suricatta (Schreber) 577

stretched out forwards on either side of tlie head. I have seen this position adopted to facilitate heat uptake only in tlie abnormal domestic situation of a floor warmed by a fire, but presumably a sun-warmed flat rock surfacc might be sim- ilarly used in natural conditions.

( 2 ) . C o o l i n g . In hot sunlight meerkats rarely persist in ac- tivity long enough to cause panting, bu t re- sort to cooling be- Iiaviour. As soon as they become hot they seek out a patch of shade and adopt tlie hearth-ruggi!ig pos- ture. If a suitable cool surface is not avail- able, the animal will sometimes scratch away

F i g . 6: Adult male, a) lying on side, b) hearth riiggiiig; both i n front of electric fire.

the warm surface soil and lay itself down on the cooler area t h u s exposed.

Toilet behaviour and comfort movements

In natural conditions a nieerltat’s rather coarse fur is kept extremely clean by frequent passage through the burrow. Extensive care of the pelage is thus not required and no elaborate toilet ritual exists. Any irritation of the sk in is, however, dealt with either by scratching with the hind foot or by nibbling a t it with the incisors - “fleaing” (Fig. 7a). Licking is relatively un- important as a toilet activity and is seldom used except for cleaning round the genitalia and anal region (b). There is, however, considerable individual varia- bility in this and Fb is much more prone than any of the other animals studied to combine some licking with incisor nibbling when removing a piece of dirt from her fur. Fleaing can very easily be evoked by tickling almost any part of the animal’s body, but the back just in front of the root of the tail is particularly sensitive. In response to such tickling the meerkat does not nibble a t the area stimulated, but makes fleaing movements wherever its mouth happens to be at the time: it is very easy thus to induce the animal to flea one’s hand. When this response was observed in Fa it was concluded that in normal circum- stances mutual grooming would occur. This expectation has been borne out, for she and the male did groom each other and mutual grooming now constitu- tes an important social activity between him and Fb (Fig. 8). Either animal may begin the grooming session by coming up close and starting to flea the partner. The latter a t once reciprocates and mutual grooming continues for sometime. It clearly has a social bond-maintaining function. Mutual grooming

578 R. F. EWER

is not confined to pairs of opposite sex, for in the wild I have seen it occurring in a group of three sub- adults.

DUCKER (1957) notes that i n Mungos mungo and Herpestes edwaudsii the teeth are cleaned with the claws of the fore feet. In Suuicatu the teeth are also cleaned in this way, but only if food particles have becoinc lodged between the teeth; it is not a regu- lar post prandial acti- vity. Similarly, the face is not washed but any pieces of adhering dirt or food are brushed off with one, or sometimes both, fore paws, using a movement which is made forwards and slightly downwards from the eyes to the snout .

When emerging from the sleeping box after a night's rest meerkats often yawn and stretch i n a high- ly characteristic man- ner. The animal yawns widely and at

Fig. 7: Adult male toilet behaviour. a) ,,fleaing" at the root of the tail. b) licking the genitalia

Fig. 8: Mutual grooming between M and Fb. (frames from a single sequence)

The Behaviour of the Meerkac, Suvicata srtricatta (Sdireber) 579

the same timc the fore legs are extended far forwards and the back is thrown into a downward arch just behind the shoulders. The rump is then thrust somewhat upwards by extension of the hind legs. This usually completes the process, but occasionally the body is thcn brought forward, so that the forc limbs are almost vertical aiid the hind limbs are stretched out behind. Somctimcs, when lying in front of the fire, the animals may stretch by extend- ing fore and hind limbs simultaneously in front and behind. I have once seen the malc stretch in this way from a standing position: the legs were simultane- ously extended before and behind so that the belly lay. flat on thc ground: thc young of the second litter quite often stretched in this way: This “simul- taneous long stretch” would appea! to be the complete, high intensity form of thc pattern with both fore and hind limbs simultaneous and maximally in- volved, while i n the other lower intensity forms the extension of the hind limbs is slower and less complete.

Micturition, defaecation and marking In defaccation and micturition a hole is iiot dug, the faeces and urine are

not buried and if an earth box is provided it is seldom used. A few rather ill- dcfincd scratching movements were, however, occasioiially seen before defae- cation. There appears to be considerable individual variation in this behaviour, for DUCIKR (1962) records much more definite scratching in her aiiiiiials, although no burying was done.

Thc animals select favourite places for defaecation and micturition, prc- ferably in a corner or a t lcast with a vertical surface a t their backs. In de- faecation both sexes squat slightly with the hind legs wide apart and thc base of thc tail arched upwards. The female adopts the same posture in micturition. In thc male, however, thc micturition posture is like that of a dog, one hind leg being raised and the urine directed against some vertical object. The faeces normally form an elongated pellet of firm consistency which comes away cleanly from the anus. If, however, some slight digestive irregularity causes thc faeces to be softer, the anal region is cleaned by wiping it on the floor two or three times in a half squatting position but this is not normally done by fully healthy animals. The fact that DUCKEK’S (1 962) animals always cleaned thc anal rcgion in this way iiidicates that their fluid balance was slightly a t fault; a very common occurrence in captive animals. DUCKEK quotes this anal cleaning pattcrii as being restricted to mustelids and viverrids, but I consider that shc attaches too much phylogeiietic importance to it, for dogs will readily use the same pattern if necessary to remove a piece of faeces clinging to the anus aiid I have seen a cat d o the same.

Whcn the litters of young were about 10 weeks old defaecation took on a social character. The young did not necessarily defaecate i n the same place each day, but once one had selected a place, the rest of the litter would defae- cate therc too, so that a communal pile of dung was produced.

The male Sid~icutu has anal glands which produce a strongly. smelling sccretion, which is used to mark various objects. In marking, one hind leg is slightly raised, the rectal wall everted to expose the openings of the glands aiid the anal region wiped along some solid object (Fig. 9.). He frequently then rubs his body along the mark so as to smear the secretion on his own fur. Although projecting objects such as corners of walls or edges of doors are preferentially marltcd, flat surfaces are also used. In the house, marks on particular places are frequently renewed. In addition, a few corners of walls in the neighbour- hood have becomc marking points. When out for a walk, if the male passes close enough to one of these, he will snifl i t and then renew the mark. The

580 R. F. EWER

F i g . 9: a) Adult male, marking entrance to sleeping box, b) young approximately 6 weeks old: the adul t markings are now well developed

smell is still detectable by him after the elapse of a fortnight. Females have no anal glands but may perform the marking pattern although, of course, no smell is produced. Their readiness to do this is extremely variable: Fb, now a year old, has never been seen to mark; Fa did so on a few occasions when she was much agitated, while Fc, at the age of 6 months, marks very fre- quently as did the female kept by D ~ ~ C K E R (1962).

In conditions of captivity it is impossible to decide what the normal significance of marking may be, but a few points are clear. Firstly, the entrance to the sleeping box is marked so regularly and so frequently that i t seems certain that similar behaviour would occur near the entrance to the burrow and that it would serve to indicate occupation. Secondly, whenever the male is thrown into a state of excitement or agitation he marks extensively on the nearest vertical object. Although in these circumstances marking may have a displacement character, i t might serve as a warning signal to others visiting the spot later.

Food capture and feeding The main natural food consists of insects and other small invertebrates

which are dug up with the long claws of the fore feet. In foraging, the surface of the ground is rapidly scratched, the nose continually investigates the area and if the presence of food is detected, then digging is continued until the food is unearthed. In normal digging of this sort the feet are either used alternately or else a few successive movements are made with one paw, then with the other. The two fore feet are not usually used simultaneously unless an obstacle is encountered and it is necessary to exert greater force. If, however, a major excavation is being made, both may be used to throw the soil out between the back legs.

Scratching with the fore feet is a pattern with a very low threshold and one " which seems to be almost inexhaustible. In captivity, where true foraging is usually neither necessary nor possible, the scratching pattern is, nevertheless, shown very frequently. Any small crevice or hole is scratched a t and the activity is persisted in even when the animal can have no possible expectation

The Uchaviour of the Meerkat, Suricata suricatta (Schreber) 581

of finding food. Such “scratching for its own sake” can be distinguished from true foraging by the fact that the nose is not kept busy investigating the area being worked. Scratching is, however, most persistent a t crevices from which something can be extracted, regardless of the fact that the material extracted is not edible. For example, I have seen Fa devote a great deal of effort to removing gravel from a barrel through a small hole. Meerkats will industri- ously demolish a patch of loose plaster i n a wall; if they get on the dining table they will empty every salt cellar and sugar bowl of its contents and for them a pipe containing ash constitutes an irresistible invitation to scratch out the contents.

It is not surprising that this appetitive component of food finding should be so persistent and so independent of obvious external reward. In fact, on teleononiic grounds one might expect that any relatively complex appetitive behaviour concerned in food finding would be “self-rewarding”. If this were not so, then in conditions of scarcity an animal might simply “give up” - i ts pattern exhausted - and starve to death before it had met with sufficient reward to reinforce the pattern. That a well fed dog will hunt is a common observation and the behaviour of human anglers also has all the objective manifestations of n pattern performed with little relation to reinforcement by reward.

In genuinc foraging, although the meerkat’s nose is continually a t work as the prey is being dug out, the jaws are kept tightly closed and the prey is not bitten until it has been fully disinterred. If it is large or unfamiliar it is givcn a thorough knocking about with the claws of the fore feet before being bitten, and even then a few rapid test nips may be made before true eating starts. The first genuine bite is usually accompanied by a characteristic side- ways shake of the head - the “death shake”. This is so much a part of the fecding pattcrn that it is normally shown when a fully experienced animal is given iion-living food, even if , as with ripe tomato or jelly, the shake merely results i n scattering the food.

Although digging for insects is the main food-finding pattern, larger prey is readily taken if opportunity occurs. Mice, small birds, lizards or snakes are quickly killed and eaten. The claws are used to assist the teeth in coping with such large prcy. The pattern here is highly characteristic: the claws are inserted into the prey close to the mouth and pulled downwards, the head meanwhile being held high. Once the claws are on the ground they may retain their hold on the prey while further movements of the head help to tear it in pieces (Fig. 10). LEYHAUSEN (1956) records a somewhat similar tearing of the prey in Puradoxurus hermuphroditus. I have never seen any tendency to “play” with the prey after the manner of a cat.

Fig. 10: Use of the claws to assist in tearing up a mouse. (b) and (c) are successive frames

%. f . Ticrpsychol. B d . 20. H e f r 5 3R

582 R. F. EWER

It is unlikely that Fb and Fc, captured very young, could have had prc- vious experience of mice as prey; even the male, who was not fed live prey a t the zoo, was probably without experience of this type of food. Tests of the responses of all three animals to mice were therefore made. There was no innate recognition of a mouse as prey, but once the mouse ran away, pursuit was immediate. No innate tendency to kill by means of the neck bite was shown: the prey was bitten more or less a t random aiid in fact was very soon killed, more rapidly by the full grown male than by Fb, then not quite mature. In a number of tests with these two animals the mouse was always eaten from the head down and devoured completely without leaving any remains.

The tests with Fc require separate consideration. A t 3, 31 /2 and 4 months old her responses to a mouse were tested. O n each occasion she chased the mouse when it ran, but showed no recognition of it either as “prey, to be killed” or “food, to be eaten”. This failure to respond may possibly be abnormal. H e r sleeping quarters in the laboratory were i n the same room as the mouse and rat cages, and she may therefore have become conditioned to their smell. Certainly a t a stage when her only rcsponsc to a mouse was to chase it, shc would readily kill and eat a lizard of larger size. A t the same time, it must bc noted that there is clearly great individual variation in the response to live mammals, for DUCKER (1962) found great differences in two identically treated female litter mates. Although the reason for Fc’s deficient killing behaviour is thus uncertain, the following observations arc of some interest. When she was seven months old, Fc was offered a mouse, and her bchaviour was as it had been i n previous tests. However, the niousc was rather a small one and was ultimately killed, not in a purposive manner, but by the same sort of random biting as might have been given to any plaything. There was still no recognition that the mouse was food, but by teasing her with it she was presently induced to puncture the skin and tasted the flesh. The mouse was then eaten, not from the head down, but from where the first incision happened to have been made. I t was intended to let a week elapse bcforc the next test, but on the following day an escaped mouse was discovered i n a wooden box in my laboratory. Before I had time to remove it, Fc jumped into the box, chased the mouse with more decision than had previously been shown and in a matter of seconds had killed it and was eating it from the head down. This “learning” had about it a trigger-like, all-or-none quality, which made it quite unlike normal trial-and-error learning. One could not avoid the impression that the whole pattern was in fact already there, but requiring sonic form of facilitation, which the first killing and eatin? provided.

When she was 8 months old F a was given a slightly damaged small bird. She sniffed a t it and then lost interest but returned when the bird squeaked and fluttered. After a few half hearted bites and some pulling about with the fore feet she ultimately seized it by chc head and started to eat. As usual with large prey, she used the fore paws to assist in tearing it up. This resulted in some feathers being torn off but this was purely incidental, there was no sign of organised plucking, although the feathers wcre very troublcsoine and made eating the prey very difficult.

In the case of lizards and snakes the orientation of biring was determined by the movement of the prey, the most actively moving par t being attacked. With lizards aiid a small non-poisonous snake, this was usually the tail, but whenever the snake reared u p its head, but it is clear from the responses to lizards that this is not an ininate pattern involving ing to strike this pattern would result in the meerkar’s attack being directed towards the head, but it is clear from the responses to lizards that this is not an innate pattern involving any true orientation towards the head as such, but a more general response to movement of the prey. In contradistinction to mice, snakes and lizards wcre catcn from any end, head or tail, apparently quite randomly. DUCKER (1957) has made similar observations on the responses of Herpestes to snakes and limbless lizards and also concludes that the celebratcd snake versus mongonse duel involves nothing more complex than siniplc responses on the par t of the mongoose to the characteristic movenienrs of the snake.

The unlearnt responses of Suricata to large prey thus seem to comprise three things: the tendency to chase any small object running away; the ten- dency to bite a t the most actively moving part and an orientation of eating from the head down in the case of hairy prey.

H a r d shelled objects, such as snails and eggs are bitten. If they are so large tha t the teeth cannot get a satisfactory grip, then after some vain attempts, they are abandoned. A number of viverrids deal with objects of this sort b y throwing them down until they break: At i fux pafudinosus (G. Cuv.) grasps them in the fore paws and throws them vertically down on the ground while Myonax pufverulentus (Wagner) hurls them backwards between the

The Bchaviour of the Mccrkat, Suricuta sttricatta (Schreber) 583

hind legs. Mungos rnungo ( D U C K E R (1957) niay use either vertical o r backward throwing but Suricuta was never sccn to do cithcr of these things. Thc animals would, however, when fnccd with a hen’s cgg, sometimes push it slightly backwards with thc fore fect so that sevcral times I thought they were about to show thc Myonax pattern, but they never did so.

In the wild, nicerkats have been sccn digging u p and eating various bulbs and tubers and I hnvc seen my domesticated ones do the same. Fa’s litter of young chewed the leaves of a species of Gastrriu (a succulent, much appreciated by goats) growing in the garden and Fc ate thc juicy white lowcr srcms of grass. I n the wild these types of vcgetablc food must be important as a source of moisture in drought conditions. In captivity meerkats become cxtrcmely omnivorous and as well as nicat, poultry, eggs, checsc and milk, come to accept rcadily a vnricty of fruits and vcgctnblcs such as grecn pcas, carrot, tomato, banana. Avocndo pear is a great favourite and I have heard of wild nieerkats coming into a farm garden to eat fallen avocados. Considerable individuality in food prefcrcncc is, however, shown.

Mccrkats show a vcry high degree of food envy. They attempt to snatch food from cadi othcr, o r from thc domcstic cats and cvcn i f they are not hungry the sight of another animal caring is quitc sufficient to make thcni snatch away the food. H o w strong food envy cnn be is illustrated b y the following incident. Fc was once given a fcw Cape gooseberries, which she atc, but promptly vomitcd up again after a few minutcs. Thc following day shc was oriered n gooscbcrry, to scc whcther she had lcarnt not to eat it. She smelt a t it, but rcfuscd to ent it, cvcn when it was enticingly rolled along the floor so that she chased after it. A t this point the laboratory cat entered the room, canic ovcr and sniffcd at the fruit. The mccrkat instantly dnslicd up, seized the gooscbcrry from under the eat’s nose and ate it.

Thc biological significance of food envy will be discussed later, when dealing with parent-young relationships. When two meerkats are feeding together each may t r y to steal the other’s food. The defence against this is to turn round vcry rapidly so as to present the hindquarters to the would-be thief and keep the piece of food out of his reach. In feeding from a dish, the same rapid turning movement is used to attempt to push others away from the feeding dish. If one animal gets his head well into the dish, he mayl by rapidly spinning round, succeed in keeping the rest from the food for a time, fending thcm off with his hindquarters.

Attack and defence

In purc defence the meerkat adopts the normal carnivore posture, throw- ing itself on its back, with claws and teeth directed towards the aggressor and the vulnerable nape of the neck protected. Except in prey killing pure attack is not often seen, but consists of a quick rush at the enemy and a power- f u l bite delivered with great speed. More usually the presence of an enemy or source of danger produces a situation where tendencies to attack and to avoid conflict are united and a number of characteristic patterns may then be shown.

Inter-specific encounters

(1) G r o LI n d p r e d a t o r s. The sight of a terrestrial enemy, such as a strange dog, usually evokes pilo-erection. This is combined with extension of the legs and arching of the back, the tail is held stiffly erect and the head is slightly lowered. The result is a very dramatic change: what was a long- bodied, low-slung animal suddenly becomes converted into an almost spherical object of greatly incrcased apparent size. The meerkat now frequently ap- proaches thc enemy with a highly distinctive gait which I have called “stiff- legged rock”. I t moves forward at a gallop, but keeps the legs very stiff and the back arched. This gait is clearly a compromise, combining tendencies to attack and to refrain from doing so. Although in fact a gallop, forward pro- gress is extremely slow, thc animal jumping high in the air at each step, but moving forward very little. The result is that it see-saws up and down a t each step and presents a truly alarming appearance (Fig. 11). The advance is usually nccompanicd by growling. Should the enemy approach closely, the meerltat

3 x *

584 R. F. EWER

F i g . I f : Successive framcs showing F a performing stiff-legged rock. I n the scrics taken from behind (a to h) the intensity is less and the hind legs arc not raised so high RS in the scrics taken from the side (1 to 9)

growls furiously and stands in the arched-back position with hair erect. It may then alternately move slowly backwards and advance again and dar t the head towards the enemy with a sudden explosive spit. Although a real bite may be delivered in these cicumstances, this does not usually occur, but I have seen a dog put to flight by a bite on the nose.

When an enemy is near, but not dangerously so, the meerkat frequently performs displacement digging. This differs form normal digging i n that i t is carried out with both fore feet together and the gaze is directed towards the enemy instead of the excavation. Displacement digging occurs very frequently in any situation where the animal is agitated and the sight of a potential enemy or a strange person is usually sufficient to evoke it. Correct afferent feedback from the feet is, however, necessary. Displacement digging is per- formed only on a suitable substratum: on a tarred road or similar hard surface it does not occur. This is easily demonstrated with the animal on a lead, for i t can be manoeuvred from the tarred road to the grassy verge and back again and displacement digging stops and starts according to the character of the substratum. Two factors are probably important in determining that digging should be the pattern resorted to as a displacement activity. Firstly, as pre- viously mentioned, digging is a low threshold pattern and almost inexhaustible: the animal is almost always ready to dig and the centre concerned requires very little extra excitation to bring it into activity. Secondly, the motor pat- tern involved in stiff-legged rock, which includes simultaneous movement of the fore legs with little forward progression, bears considerable resemblance to the digging pattern. LIND (1959) has pointed out the importance of such similarity of motor pattern in the initiation of displacement activities and DUCKER (1957) notes that in genets stretching may be triggered of€ if some other activity happens to bring the animal into an appropriate posture. Although the displacement digging pattern is so regularly shown in any dan- ger situation, it has not been in any way ritualised to serve as a warning to conspecifics and this for a very simple reason: vocal warning cries already deal adequately with the situation and a further signal is not required.

The Uchaviour of rhc Mccrkat, Suricata suricutta (Schrcbcr) 585

SPUR\VAY (1953) has suggested that in domestication there is a sort of hehavioural symbiosis between dogs and cats. Not only does the cat provide the dog with something on which to expend his pent-up hunting drive, but it is eqiially important for the cat to have some releaser for its escape pat- terns. Introspectively and from observation one knows that in inan situations involving a certain danger element are often deliberately sought out. Some- thing similar seeins to be true of meerkats: they deliberately leave the shelter of the garden, where foraging facilities are adequate, and go on the road where esperience has shown that dogs are always met, and one gets the im- pression that there is a pleasurable component in hostile encounters.

(2) A e r i a I p r e d a t o r s. In natural conditions hawks are a inecr- kat’s commonest enemies. The responses to aerial predators are extremely complex and clearly embody an innate component, maturation and learning by experience. To unravel the roles of these three factors requires a detailed experimentiil study, but the observations that have been made are here re- corded as they give a few indications of the complexity of the behaviour.

\Vhcn out of doors niaturc adults keep a sharp look out and periodically scan the sky for potcnri.il predators. HECK (1956) remarks on their vigilance in this respect. A hawk is noticcd cven whcn high i n the sky, thc alarm call is given and the hawk is carefully watched for a considcr.tble time until it either moves away or is quitc clearly not about to attack. I-fnrmlcss spccics s u c h ns storks or ibiscs arc mcrcly givcn a quick glnncc and thcn n o furthcr notice is tnkcn of them. O n one occasion the young female, Fb, and tlic malc, thcn fully ndult, were o u t together. A stork flew ovcr and the female gavc the alarm. Thc male responded h y luoking up, saw tlic stork but paid no furrhcr attention to it. Thc young fcinnlc, liowcvcr, continued t o watch it and gavc the alarm call until it disappeared from sight. O n another occ:isioii Fn, thc male and their family of young (thcn 9 wecks old) were in the gardcn when an ahdidah ibis flcw over quitc low. The young flcd, panic-stricken, for covcr but the adults merely glniiccd nt thc bird and took no action.

These observations suggest that the meerkat’s innate behaviour includes a tendency to look upwards and to respond by flight or alarm calling to the presence of any bird and that they later learn by experience which species are harmless. There is, however, a complication. The adult animals have frequent- ly seen hawks, but have never been attacked by them. They nevertheless still give the ;ilarm call and remain vigilant in the presence of a hawk, although harmless species have ceased to evoke these responses. This might be taken to suggest that there exists some innate mechanism which prevents the waning of the response to a hawk even in the absence of attack, whereas with birds of a different shape, experience unaccompanied by attack leads to waning of the response. There is, however, another possibility. Although hawks are relatively common i n the neighbourhood, they seldom fly low, whereas the harmless species sometimes fly over a t little more than tree top height. It niay therefore be that before a bird is accepted as harmless the nieerkat must have experience of its flying low and failing to attack: merely seeing it at a distance without being attacked may not suffice.

Some observations on responses to acrop!anes havc also bccn made. Until M was over a ):car old ncithcr he nor Fa (thcn 3 years old) had seen aeroplanes. At this atage a local twicc wcckly air scrvicc was cstablishcd. Their first sight of an aeroplane threw thc two niiimnls into complete panic and they fled precipitately to the shcltcr of their slccping box. After a few cspcricnccs, howcver, flight gave way to vigilant watching, the hawk warning hcing givcn all thc tinic the plane was within sight. The male very soon Icarnt to rccognisc the sound of the planc and whcn he heard it would run to a look-out position whcrc i t was visihlc to him and would watch it carefully, giving the alarm call, until it vanished from sight. His rcsponsc, howcvcr, is diffcrent whcn he is out walking and thus not within reach of the familiar refuges which arc available a t home. I n this situation a n approaching planc still cvokcs flight to the nearest covcr. I t is also noticeable that sight is much more important than sound i n the respoiisc to planes; moreover, the animals can judge as accurately as I can whcther a plnnc is coining straight towards us, or is veering off to onc side. The intensity of the nlnrm c:ill falls off thc instant an approaching plane alters coursc.

586 R. F. EWER

Intra-specific encounters

Two zoo keepers have told me that i f a strange meerkat is introduced to a group in the confined conditions of captivity the intruder will be attacked and probably killed and on one occasion, in my absence, a young female was put in the enclosure with Fa and M and was killed. Nevertheless, it is possible to bring strangers of opposite sex together without this happening. The male, not quite fully grown at the time, was successfully brought into the home of the original female, Fa, then 3 years old and later, after her death, the young female, Fb, was accepted by the male. In both cases there was considerable aggressive behaviour, but two very distinctive patterns served to prevent serious consequences.

(1) B a c k a t t a c k . In “back attack ” the m eerk at turns round and moves to- wards the partner rump first. In fact this behaviour is used in defence as well as i n attack, for an animal that is being di- rectly attacked may spin round and present its quarters to- wards the aggressor. Back at- tack was first seen being used by Fa against the domestic cats and was later often used by the young male in play fighting with a kitten (Fig. 12). It is also common in intraspecific encounters, both between the adults and amongst the voung. It has, however, never been

Fig 12: Back attack by M in play fight with half grown cat cat and is clearly normally used only with conspecifics, the domestic cats having been accepted niore or less as fellows or a t least not regarded as dangerous enemies. The pattern appears to represent an elaboration of the normal back turning used to prevent food theft which has already been described.

DUCKER (1957) describes a similar back turning posture i n Herpestcs. Here the pattern seems not to have reached such an advanced stage, for it is used only in defence. In Suricata its use in attack as well would seem to represent an evolutionary advance. I am indebted to Dr. A. J. ALEXANDER for pointing out that the back-attack pattern, coupled with the ten- dency to mark when in a stage of high aggressive excitement provides the basis from which the skunk’s method of defensive attack on enemies might have been evolved. Although, apar t from its elaborated form in skunks, the back defence andJor attack pattern has to date been seen only in Herpcstes, Suricata and Martes (HERTER and OHM-KETTNEK 1953), it may be commoner in carnivores than these records suggest for I have seen a very similar form of back-attack used by a mongrel terrier dog.

(2) I n h i b i t e d b i t i n g. This is a very distinctive meerkat pattern, which is of great importance in preventing mutual destruction. In inhibited biting the jaws are held firmly closed, the head is darted forwards towards the partner and at the same time moved rapidly from side to side. When two animals perform this pattern simultaneously, the effect is reminiscent of two fencers sparring for an opening. In inhibited biting, as the side to side move- ments of the head are made, the animal will, if possible, bring its head into contact with the partner so that the chin or side of the face is rubbed against the latter‘s body. RENSCH 8: DUCKER (1959) describe a homologous pattern in

seell towards a strange dog or

Thc Uehavlour of the Mccrkat, Surtcata wr tca t ta (Schrcbcr) 587

Hcrpcs tes cdwurdsii, but here it is the top of the head, not the chin or cheek, that is rubbed against the partner. These authors, however, consider that the pattern is an “invitation to play” and DUCKER (1962) interprets the Suvicatu pattern in the same way: This cannot be correct, since although the pattern may be shown in play, it also occurs in a variety of situations which have nothing to do with play. The thing common to all the situations in which this pattern was seen is that a strong tendency to bite i r combined with social inhibition against doing so.

Inhibited biting w a repeatedly observed i n Fa before the advent of the malc, always i n circumstances where she might have been expected to bite, but did not actually do so: for instance when a member of the family had rcturned after a period of absence, or while the animal was gradually beconi- ing accustomed to a stranger. When Fa and the male were first brought together inhibited biting and back attack occurred very frequently between thc two animals. Later on, when Fb was introduced to the male she was ex- tremely aggressive and attempted to drive him away with genuine attempts to bitc interspersed with inhibited biting. He, however, although he could easily hnvc killed her, responded by back attack and inhibited biting only. Aniongst the young both these patterns were also shown i n situations where fights over food tended to dcvelop.

Inhibited biting appears to be a pattern which has arisen by a process of claborntion from thc normal investigatory movements of the head that are madc as sniffing accompanies digging for food. This suggestion as to its origin is made for two reasons. Firstly, I have several times observed that if a mcer- kat is forasing for food, looks up and sees a dog in the distance and at the same time its chin comes in contact with the vegetation, it may go over into thc inhibited biting pattern and I have, i n these circumstances, seen all grades of intermcdiate bctween normal food finding head movements and clear in- hibited biting pattern. Since the sight of an enemy in an uncomplicated situa- tion never cvokes inhibited biting, I consider this observation to be of con- siderablc importance, as showing that the addition of the food finding compo- nent to the aggression provoked by the sight of the enemy results in inhibited biting. Secondly, the food finding situation is one in which a strong stimulus to bite given by the smell of the food is firmly inhibited. As has already been mcntioncd, food is not bitten until it has been completely dug out and, if iicccssary, rcndered harmless by preliminary attack with the claws.

Sexual behaviour

In copulation the male grasps thc female round the body with his fore paws, vcry much as a dog does (Fig. 13). The neck grip is not used during actual copulation, but was seen sevcral tinics before mo LI n t i n g occ LI r red. When thc male was introduced to the 3 year old Fa, he made attempts to copulatc aln1ost a t once, but she repulscd him. In this situation, hc grasped her firmly by thc neck without, however, closing his jaws sufficiently to wound her, and dragged her about. She became pas- ~ t g 1.3. Copulatory position: M mounting FL

588 R. F. EWER

sive when gripped in this way and presently allowed hini to mount. The neck grip seemed to be used purely i n order to induce passivity i n the aggressive female. A t other times sexual behaviour was always preceeded by a bout of semi-serious fighting. In this, one of the animals frequently bites a t the partner’s nose and grips i t between the jaws but does not close them suffi- ciently to cause damage. The significance of this nose biting is not understood. The female was not seen to adopt any specific posture facilitating mounting or intromission.

Passivity in response to a neck grip is not restricted to females. Aninials of either sex hang limply if lifted by the skin a t the nape of the neck. The role of the neck bite in prey killing, carrying of the young and copulation and the possible evolution of i ts use in these different contexts are discussed by LEY- HAUSEN (1956).

The male, a t 3 years old, became much less sexually active than he had been when younger. Fb frequently attempted to incite hini by nipping a t him, particularly a t the tufts of hair on the cheeks. This usually led to the same sort of semi-serious fighting as was observed to preceed copulation between him and Fa. When the male’s general level of excitation had been raised by the fighting he often attempted to mount. Earlier on it was also noticed that when he played with the first litter of young and became excited he would frequent- ly adopt the copulatory pose and I have seen the same thing happen during play in a group of half-grown individuals in the wild. A siniilar tendency for the generalised excitation of rough play to go over into sexual behaviour is frequently seen i n dogs. Both sexes are capable of reproduction towards the end of their first year of life. The male was just under a year old when he fathered Fa’s litter and Fb’s first litter was born when she was a little more than a year old.

Reproduction and parent-young relationships The period of gestation could not be determined accurately, but since

sexual behaviour between the male and Fa was much in evidence during the last few days of September and first week in October and their young were born on December 16/17, i t must be approximately 11 weeks. During thc latter part of gestation the female’s teats, normally very small, increase in size and become more prominent. The increase becomes noticeable approxi- mately a month before parturition. Fa’s young were born some time during the night of December 16/17th, 1960. The birth was not witnessed, as the female gave no sign of impending parturition on retiring to bed a t night and in the morning the four young, all females, had been born. The same thing happened with Fb’s litter, born on the night of November 22/23rd, 1962. Again there were four in the litter, one male and three females, bu t one (the male) died during the first day, apparently as a result of suffocation. Although there are six mammae, a female in the wild is rarely seen with more than four young and this is probably the usual litter number. Five days after parturition Fa had a brief period of oestrus and the male attempted to copulate with her. No pregnancy resulted, but this might have been because the two were not kept permanently together during this period. No post-partum oestrus was apparent with Fb.

Parental behaviour After the birth of, the first litter the male was separated from the female

and young for the first three weeks and allowed to be with them only for brief periods when I was able to be present. O n these occasions he showed interest in the young, but no signs of aggression. It was therefore concluded that the precaution of removing‘the male was not necessary and with Fb’s

Thc Uchaviour of the Mcerkac, Surlcata S N Y I C U ~ ~ U (Schreber) 589

litter this was not done. His parental behaviour was much more fully deve- loped with this second litter, partly, no doubt, because he was older, but his early deprivation of the company of the young in the first case probably had some effect. His presence may also have been partly responsible for the fact that Fb WJS calmer in her general behaviour and was content to keep her young in the L I S U ~ I sleeping box, whereas Fa was a t first much agitated. She would not Iteep her young in the sleeping box but carried them hither and thither and it was some time before a satisfactory nest was found and she settled there with them. Both females would retrieve scattered young either by picking them up i n the mouth or simply by pulling them in with the fore feet. Both would also carry a young one in the mouth if they wished to accom- pany a number of the family out of the room in which the sleeping box was situated. It is somewhat surprising to note that the methods of carrying the young adopted by the two females were different. Fa always took hold of hers by head or neck, very much as a cat carries a kitten (Fig. 14 a). Fb, on the other hand, a t first carried hers by the middle of the body, as a rat does (b).

Fig. I d : (a) Fa carrying 16 day old offspring. (L) Fb carrying 6 day old offspring

As the young grew larger, Fb seemed to have difficulty i n carrying then1 in this way and she altered her grip, now taking hold of them by the skin of the thigh. DUCKEK (1962) notes that although her female did not carry the young, a keeper a t the Miinster zoo reported having seen another female do so, grip- ping the young hy the middle of the back, as Fb did.

A t first the female crouches over the young to suckle them i n a posture somewhat resembling the sleeping position (see DUCKER 1962, Fig. 1). As they become larger it becomes increasingly difficult for her to accommodate them thus and by the third week she begins to lie on her back to feed them (Fig. 15 a). During the period of adjustment she may suckle the young a few times in the lazy si t position (b), which provides an easy transition between the original crouch and the final belly up pose.

When her litter was 10 days old, Fa became very il l for a few days and the young had to be bottle fed. After she recovered it was some time before her milk flow returned to normal. Detailed observations on the feeding be- haviour of the young were not made, as the situation could not be regarded

590 K. F. EWCK

Fig . 15: (a) Fa lying on her back to feed the young (5 wceks). (b) Fb feeding her young in lazy sit position (16 days)

as normal. With Fb, however, once she had taken to suckling the young lying on her back, observation of the behaviour of the young was easy. It was noticed that a t each feed the young would each suck from several teats in turn, so that all six mammae had usually been drained by the end of the feeding period. Teat constancy of the type found in domestic kittens (EWER 1959) was not shown, but each young one usually began a feed on a particular teat, al- though it might subsequently use the others in a random manner. This indicates that although no teat ever became the exclusive property of one young done, some ability to recognise individual teats does exist. This is of some interest, as this ability is a necessary prerequisite for the evolution of the more rigid and complex organisation of feeding behaviour in kittens. A fuller a x a u n t of these observations is given elsewhere (EWER, in press).

Movements of the fore paws against the maternal mammary glands were niade by the young as they fed. The movements were usually rather indefinite, but now and then a short series of alternate thrusts of the two paws occurred. These, however, never developed into the strong and definite “milk tread” characteristic of kittens.

DUCKER (1962) reports that the litter she studied purred, both when feeding and i f cradled gently in her hand. No purring was noticed in Fa’s litter but with Fb’s special attention was devoted to this point. I did not succeed in inducing purring by any form of handling but during their fourth week a very faint sound somewhat resembling purring was first heard. The sound was audible only if one listened carefully a t close quarters and I was unable to determine how it was made. It may have been rudimentary purring but, unlike the loud purring of kittens, was clearly without social significance and after a couple of weeks it ceased altogether.

In addition to suckling her young, the female also performs toilet duties for them. As with most nidicolous mammals, the young are a t first incapable of micturition or defaecation without external stimulation, which the female provides by licking the perineal region. Care of the rest of the body is provid- ed by fleaing (Fig. 16), but neither Fa or Fb cleaned her young by licking, apart from perineal licking. O n the other hand, DUCKER’S (1962) female cleaned her young by licking as well as fleaing and she also used her claws to part their hair so as to be able to reach the skin with her teeth. I have never seen the latter pattern.

Tlic Uchnviour of rhc Mccrkat, Suricata srrricafta (Schrebcr) 591

The iii,ile did not undertake any toilet duties for his first litter, but with the second he did so extensively. H e spent much time grooming the young by fleaing them but was never seen to lick them. His activities in this respect appeared to be important in ensuring his place as part of the socially inte- grated family group.

Although no animosity was shown towards the resident members of the family, all three adult rneerkats became much more aggressive towards any kind of intruders when young were present. This was particularly obvious with Fb’s litter. The day after their birth the male started to attack a domestic whose presence had never previously aroused hostility and the following day Fb, with great ferocity, chased off a strange tom cat whose previous visits to the house had met with no opposition from her. Another manifestation of the male’s tendency to defend the young was shown in an unnatural situation. H e came upon a litter of domestic kittens i n their nest box while the mother was absent. He cliinbed in beside them and when the mother returned to feed her yoiing, drove her off with great fury, clearly defending the helpless young against a dangerous predator.

In addition to direct defence of the young against possible enemies the male showed a general tendency to guard them. While they were sti l l too young to leave the sleeping box he would never be absent for very long and would return to them a t frequent intervals froin whatever part of the house he happened to be and briefly sniff them over. Towards the end of Fb’s preg- nancy she became rather inactive and the male was frequently taken for a walk on his lead alone. After the birth of the young, however, he refused to do this. H e would leave the house with his usual alacrity, go a few yards, then stop and run home again as fast as possible. Furthermore, when Fa’s young were finally given away at the age of 12 weeks the mother showed no sign? of being pertubed at their disappearance, but the inale ran uneasily hither and thither about the house, apparently searching for them.

When the young of the first litter started to play actively the male joined in their games, but Fa very rarely did so. This difference was partly due to the fact that the male was himself still quite young and playful, whereas Fa, a t three years old, was no longer prone to indulge in this activity. Never- theless, although the inale was three years old when Fb’s litter was born and had virtually given up play, once the young started to play, he joined in, although less freqiieiitly than in his younger days. Fb herself, although young, joined in the play only to a very limited extent.

One of the most striking pieces of parental behaviour that was observed concerns the female’s feeding pattern. Fa was normally an extremely greedy creature, showing great food envy. When the young were four weeks old she would snatch food froin them even though she had herself just been fed and could not have been very hungry. It should be pointed out here that I had started to give the young solid food as soon as they would accept it. One

592 K. F. EWER

would, of course, espcct rcad- iness to eat solid food to mature in advancc of the tiinc when i t nor ma I 1 y becomes a vai 1 ab I e : the female’s behaviour suggests that a t four wcclts of agc wcan- ing would not yet havc started i n natural conditions. During the next two wecks a radical change was observed. At first Fa merely secmed rather disin- clined to eat and T wondcred if she were ill. By thc time the litter was six wccI<s old, how- ever, it was clear that a ncw “feeding-the-young” pattern had developed. Shc would now take a piece of food i n her mouth but not swallow it. Zn- stead she would run up and down with it in her mouth as though inciting the young to come and take it. Since by this time they showed intcnsc food envy, their response was to /-\ dash up to her, snatch the food from her lips and devour it. T f the young were all busy cating when the feinale was given food, she still did not eat i t herself but would run from onc to another, vainly trying to get someone to snatch it. If they still did not do so, she would filially lay the morsel down besideone of theyoung(Fig. 17).

Fzg. 17: (a) Fa carries a piece of meat to one of She did exactly the Salllc w i th the young (9 weeks old). (b) The youngster has taken insects that she dug UP in the the meat and the inother watches it cat. (c) The garden. These were picked up youngster uses the claws to assist in tearing up the alld held in the mollt]l unt i l one meat. (Frames from a single sequcnce) of the young snatched t h cni

from her. That this is an innate pattern performed without comprehension was abundantly clear from her behaviour in the presence of excess food. The feeding dish might be full, every youngster eating, and yet the female would not herself eat, but would carry the food to the young regardless of the fact that they were already fully provided.

With Fb’s litter, knowing in advance what to expect, it was possible to observe the initial stages of the maturation of this pattern. The first indi- cations were shown when the litter was 22 days old. Instead of a t once eating a piece of banana, Fb held it in her mouth, then went to where the young were and ate it herself. During the following week this behaviour was seen more frequently and by the 30th day she had definitely started to give food

The Bchaviour of the Meerkat, Suricata snr ica t ta (Schreber) 593

to the young. During the next week the pattern became more marked and her behaviour was very similar to that of Fb, with one slight difference. Fa always fed her young first, indeed it was sometimes difficult to persuade her to eat herself and even her favourite foods were given to the young. Fb, how- CVCI’, would usually herself eat a little before starting to carry food to the young and a few delicacies she did not share with them. In the more natural situation o f foraging in the garden, however, most of the prey she caught was givcn to the young.

This bcliaviour made clear the biological significance of food envy. The young respond to the sight of another individual with food by attempting to snatch it away. As a result, not only are they easily fed by the mother, whose greater strength and experience make her much more adept a t finding insects, but i f she has discovered any slightly unusual type of food they too quickly learn to cat it. In such omnivorous creatures as ineerkats this may be of considerable importance. In the domestic situation this is easily demonstrated. The young of both litters, when first offered banana, did not recogiiise it as food and showed no interest in it. However, when the mother was given banana i n their presence they snatched it from her and ate and thereafter accepted it .IS food and soon became extremely fond of it. In this way “ food tiadrtronY i n relation to whatever happens to be locally available could easily be established and handed on. Fa continued to give food to her young unt i l they werc about 10 weeks old, when her tendency to feed them in this way, although it had not yet disappeared, was waning.

Thc behaviour of the malc was completely different. He showed not thc slightcst tendency to give food to the young and with the first litter would bnatch it away from them and push them out of the feeding dish (Fig. 18). With the second litter, although he never gave food to the young, he did not push them away from the dish. This was probably because he had become milch lcss voracious than in his youth and habitually gave way to FL i n food rivnlry. When foraging i n the garden he sti l l defended himself against attempts b y the young to steal his prey.

It thus nppcars that the family forms a social uni t i n which both parents are of importance. Although only the female is concerned with feeding the yoiiiig, after as well as before weaning, the role of the malc is by 110 means negligible. His greatest importance is probably as guard and defender, while his toilet xtivit ies and participation i n play have social bond forming func- tion.

F i g . 18: The malc pushes one of the young of tlic first litter (1 1 weeks) ou t of thc feedin:: dish

Fig . 19: Fb’s litter aged 6 days. Favouri tc contact position, viewed from above: each animal with its head lying over a litter mate’s neck

594 R. F. EWER

Growth and development of the young

The young are born with the eyes closed and with some hair present but it is sparse and short. For fear of upsetting the mother the young of the first litter were not handled until they were a week old. Weekly weighings were then carried out for 8 weeks. The young of the second litter were weighed at birth and thereafter each week. The values for both litters are given in Table 1. The young were at first unable to support their bodies clear of the ground but could crawl slowly and showed the same bunching behaviour as kittens do, only coming to rest if in contact with litter mates. Fb’s three young often arranged themselves very symmetrically, each with its head lying across its neighbour’s shoulders (Fig. 19). As mentioned before, the young are, from the time of their birth, extremely noisy, keeping up a continual bird-like twittering noise much of the time when they are not asleep. Fb’s litter were rather quieter than Fa’s. Their more rapid early growth (see Table I ) seems to indicate that their food supply was more abundant, which Table 1. Weights (in grams) of two litters of Suricata. I n each case solid food was first taken

during the fourth week. A full grown animal weighs approximately 1250 grams.

AGE (weeks)

A t birth 1

2 3 4 5 6 7 8

Fa’s litter

No. 1 2 3 4

_ _ _ _ 47 48 40 32 60 65 50 46

90 95 83 80

142 150 134 121 ;:. 214 180 172 - 272 243 236 - 314 279 279 - 400 364 364

Fb’s litter

No. 1 2 3 4 ~~~~ ~

32 36 29 25

58 65 58 ::.

100 98 100 -

148 148 148 - 215 209 225 - 259 253 275 - 295 290 298 - 352 346 380 - 408 412 436 -

::. Death by misadventure

may account for the difference. After a few days a more distinctive, rather high pitched repetitive note was frequently heard and this seemed to serve for contact keeping. At a somewhat later stage when they had become active outside the nest, if one of the young became separated from the rest it would make this call and its litter mates would at once run to it.

When, at the age of five weeks, Fa’s young were first permitted to follow her into the garden it was sometimes necessary to call them to attract their attention. I tried various calls and whistles with no result, but then realised that I should speak their language rather than expect them to respond to mine. Since I am very inept a t vocal imitations I tried a call which resembled the contact keeping noise only in its two major characteristics: i t was fairly high pitched and rapidly repeated, but otherwise totally dissimilar. Rather to my surprise the young responded to this pseudo-call instantaneously, re- gardless of what they might be doing at the time. From five to nine weeks this remained true: the imitation call instantly brought the young to my feet, but a t nine weeks the response started to wane and they would look up first and come only if there seemed to be a reason for doing so. Fb’s litter also responded to this call and she herself, now fu l l grown, still shows some

The Uehaviour of the Mcerkat, Suricata srcricatta (Schrebcr) 595

reaction to it. This response of the young was clearly an unlearnt innate one, released by the characteristics of the call. Its significance seems to be that of keeping tlie young together as a group, for I never heard either parent use a call of this sort to suninion the young. In fact the young always tended to rcmain near the parents and i n this the constant ”conversation” of the female may have been of some importance, not as a specific call, but rather as making it easy for them to locate lier, or possibly serving to indicate that all is well.

One very distinct response of the young to a specific parental call was seen. The first time Fa saw a hawk and gave the warning cry in their presence, her young instantly ran to her and remained pressed close against lier i n a tight group, moving with her as she finally made her way cautiously towards the protection of her human companion (Fig. 20). As long as the alarm call was being given the young remained as though tied by an invisible thread to the mother’s flanks. This response too was clearly innate.

F i g . 20: Response of the young (7 weeks) to Pa’s hawk alarm call. (a) The young stay closc to the mother whilc she watches the hawk. (b) She nlovcs cautiously to greater safety, thc young following closely. Frames from a single sequence

Fb’s litter showed exactly the same response to the parental warning call. On one occasion the inale alone gave the alarm (in response to a dog bar- king) and the young instantly ran to him although Fb was in fact nearer to them. In tlie more common situation of both parents giving a warning the young seemed to go preferentially to the mother. I never saw them separate and some go to one, others to the other parent. During their 6th week the young themselves frequently look upwards while they are out doors and at the age of 58 days gave the alarni call themselves on seeing a distant hawk. At this age, however, they still at once ran to the parents if the latter gave the alarni call.

The response of tlie young to a loud or unfamiliar noise or sudden niove- ment which did not evoke any warning from the parents was quite different. They did not orientate towards the parents but took cover immediately and remained motionless for some time. In the house this meant a dash to tlie sleeping box if it was i n sight, or otherwise under some piece of furniturc. Out of doors a hole in a bank or the nearest bush served as a refuge. This be- haviour was shown by both litters. On one occasion (already mentioned on p. 585) a natural experiment showed what happens when taking cover and a parental warning cry are in conflict. FL, on the window sill, had seen a dog and given the alarm. The young would nor reach her there and retreated to their sleeping box. Fb then came down from the window to the entrance of

596 R. F. EWER

7 8

10 13 14

15 16

17

20 21 22

23

24

25 26

27

29

30 31 32

33 35

37

40 42 43

44 45 49

50 5 2

58

62

66

Tablc 2. Development of the young and ages a t which various forms of behaviour were first observed

Fa’s litter

First sign of eyes starting to open

Eyes of all 4 fully open. Spit explo- sively i f disturbed

Legs support the body clear of the ground Scratching at crevices using 1 paw

Come to entrance of “burrow” All 4 accept raw beef

Eat raw meat, give death shake and run away with i t First efforts a t sitting u p - only lazy sit achieved Yawn-and-stretch First signs of play - biting at each other Make characteristic noise while eating. Spit with tail up and back arched when disturbed. Low sit and attempts a t high sit. Follow the female

Snatch food from female

High sit First allowed to follow fcinalc into the garden

Can now run as fast as parents Inhibited biting While out of doors often look upward a t the sky

Back attack/dcfcnce

First attack on domestic cats

No longer respond instantly when “called” Stiff-legged rock

Fb’s iittcr

Feeble attempts a t spitting Dcfinitc spitting accompanied by for- ward dar t of the head

Eyes of 2 young starting to open

Eyes of all 3 fully open First emerged from slecoing box. Legs now support body clear of ground. Scratching movements with one paw only Alternate scratching niovcnients of fore paws

Can now run actively 1 accepted raw beef and grasshoppers, other 2 refused them. Follow the female. Defaecate alone for first time All 3 cat checse. Low sit

Drink milk. Inhibited biting. Came with the parents into the gardcn to forage but returned to verandah very soon Active rough-and-tumble play

Accompanied parents to forage in garden

While out of doors look upward a t the sky

One seen sleeping alone in adult posture

Back attack/defence. Response to sight of a moving insect. First attack on domestic cats

One attempted to give warning cry on seeing a hawk All 3 gave the alarm call on seeing a hawk

When parents groom the young, the latter now reciprocate

The Behaviour of the Meerkat, Suricata suricatta (Schreber) 597

the sleeping box and again gave the alarm call. The young promptly left their refuge and followed her as she led them to the next room. Thus the response to the parental warning is made, even if this entails leaving the most favoured cover.

Fa’s young continued to suckle until they were about 9 weeks old but Fb’s had virtually ceased by the end of the 6th week. During their first 10 weeks of life a number of patterns developed. Table 2 gives the ages a t which each was first seen.

Play As in the majority of mammals, the young indulge in play very fre-

quently. As the animals become older, their readiness to play diminishes and by the time they are two years old play is seldom seen.

Fighting play is the commonest form. In this, the animals bite at each other, stand up on their hind legs and grasp each other with the fore paws, fall over and break loose and chase each other hither and thither. “Ambushing” by crouching flat on the ground ofken precedes a dash into the attack. In this rough-and-tumble fighting play two or more animals may be simultaneously involved and the male often used to join in it with the young of the first litter. At 12 weeks old the latter were given away and he was then deprived of a playing partner. With two successive litters of domestic kittens, however, he induced one kitten to become his sparring partner and bouts of fighting p1a.y between the two were common. During his second year he became more staid and no longer attempted to play with kittens although, as noted above, he did play to some extent with the second litter of young.

Presumably in relation to their burrow-living habit, meerkats like to crawl under any loose surface such as a sheet of newspaper lying on the floor, or the edge of a mat or carpet. From the shelter of such a refuge the young will dart forth to “attack” each other and will even run about with a sheet of newspaper on their backs and attack from this mobile shelter. The “mole play” described by RENSCH 81 DUCKER (1959) in Herpestes edwardsii is clearly very similar and KIPPS (1956) mentions behaviour of the same general cha- racter in an “Arabian mongoose”.

Inanimate objects are not extensively used as playthings although any suitable object niay be seized in the teeth and shaken about in a sort of “killing” or “worry-play”. The male, even after other forms of play had been virtually abandoned continued to show worry-play if a towel or some such object was dangled before him and when sweeping was in progress the broom was almost always attacked. Possibly, however, this should be regarded as a sort of substitute killing, shown only because he did not often have the oppor- tunity to kill large prey. Simple redirection worrying is certainly shown now and then. For instance, if the animal is being carried inside one’s shirt and sees a distant enemy, he may take hold of a piece of one’s clothing in his teeth and worry it.

Following The tendency of the young to follow the parents, or any other moving

object such as the feet of their human companions, is very marked. At 10 or 12 weeks old this response is waning and they become much more independent. Even the adults, however, when faken out on the lead, show a very strong tendency to follow any person walking away from them. They at once give chase, but if allowed to catch up, cease to run as soon as they have drawn level but will pursue again as soon as they are left behind. This behaviour has a strange compulsive air and I interpret it as a normal pattern being per- formed in an unnatural situation in response to an abnormal (probably super-

2. f. Tierpsyhol. Bd. 20, Heft 5 39

598 K. F. EWER

normal) releaser. Since meerkats forage as a group, i t is clearly desirable that some pattern should exist which ensures that stragglers join the main party and do not get completely left behind. This is exactly what the adult follow- ing pattern seems to achieve: functionally i t is not so much a following pattern as a “catch up” or a “don’t get left behind” pattern.

Miscellaneous A few pieces of behaviour whose significance is still obscure remain to be

recorded. The first concerns the aggressive responses of the females towards unfamiliar people. When they are young, meerkats are tolerant of strangers but aggressive tendencies develop as they grow older. In both Fa and Fb there was a rather sudden development of an extreme aversion to small children, without any associated unpleasant experience. The age a t which this happened was not noted in the case of Fa, but in Fb it began quite abruptly when she was five months old. In addition to this aversion to children Fa became ex- tremely hostile to strange human females. Although men were not often attacked, a strange woman entering the house was almost invariably attacked without hesitation or warning. At the age of 7 months Fc began to show exactly the same behaviour. Some women were more prone to attack than others, and in two cases repeated attempts to be accepted merely resulted i n bloodshed. There was no correlation of attack with stage in the menstrual cycle and no interest was shown in the female domestic cats when they were on heat. A colleague who once had a female meerkat reports that his animal, when she was on heat, would always attack women, but Fa did so regardless of whether she was on heat or not.

After her young had been born Fb, as noted above, became much more aggressive. A female member of the family returning after 6 months absence was viciously attacked and it was necessary to smack and speak threateningly to Fb before she would desist. Although refraining, after such discouragement, from direct attack Fb’s hostility was shown in a curious manner. When the “intruder” had left the room Fb would go to the chair she had been occupying, smell i t over extensively and then seize the upholstery i n her teeth and worry it with great ferocity. It was about a fortnight before Fb accommodated to the foreign smell and ceased to show this behaviour. She showed only transient hostility to a male member of the family returning after a similar absence and worrying of the chair in which he had been sitting only occurred once or twice.

A second strange piece of behaviour shown by Fa and Fb is that they both developed the habit of drinking human saliva. They would climb up and scratch at one’s mouth and then, if permitted to do so, avidly lick up saliva. The male, although he would scratch a t one’s mouth and sniff inside it, never took saliva. DUCKER (1957) describes the young of Generra suahelica licking saliva from the mouth of the mother, but the young meerkats were never seen to do this. Since saliva licking occurred when the young genets were beginning to eat solid food, DUCKER suggests that they may have been obtaining digestive enzymes from the maternal saliva. This, however, does not seem very likely since the only enzyme known to occur in saliva is an amylase and it is found only in vegetarian or omnivorous species (VONK 1941). An alternative explanation is that the function of saliva licking may be to provide fluid for the young if they are suffering from water deficit. This possibility suggested itself to me when on one occasion after Fb had been unusually importunate in her demands for saliva I noticed that she shortly afterwards took a very long drink of milk and must have been very thirsty when she solicited saliva.

The Behaviour of the Meerkat, Suricata suvicatta (Schreber) 599

General intelligence and learning abilities

I have madc no tests of S~i~ i ra ta ’5 abilities in problem solving and i n gencral have, as far as possible, refrained from attempting to teach the animals anything, since the main object was to study natural behaviour. Nevertheless, after having livcd with them for some years, some general ideas about their learning abilities have inevitably been acquired.

In lcarning, motivation is always extremely important. Unlikc dogs, mecrkats are not motivated by any desire to please their owners but, like cats, by their own requircnients. Like a cat, a nieerkat learns its name, but will answer to it only if reward is likely to follow: the response to a call that never signifies anything but food or to the sound of the refrigerator door bcing opened is as regular as i n cats and seems to be learnt with equal facility. Mecr- kats rapidly learn their way about the house and find out how to climb up to favourite lookout places. Like cats, they may learn that certain actions are not permitted but this will not necessarily result in their refraining from them in the absence of their owner. Thus Fb, although well aware that shc is not allowed on the dining table, will climb up at once if a chair offers a feasible route and she is left alone, but will jump off with a “guilty” air if discovered on the table.

In only one instance was severe punishment administered and the course of thc learning that followed is of some interest. When Fa first cncountered a litter of domestic kittens she attempted to bite them. I spent a whole evening smacking her severely every time she did so. The following evcning kittens and nieerkat were again allowed to be together and the meerkat a t once attempted to bite the kittens. She received the usual smack and thereafter ncver made another attempt to bite and, in fact, became much attached to the kit- tens. One got the impression that on the second evening she was quite aware that a bite was likely to be followed by punishment but was just trying it once to make quite certain. I have seen negative conditioning follow cxactly the same “2-session” course in a domestic cat.

A great deal of mammalian learning consists not of any change in patterns, bu t of learning in which situation to perform a certain pattern and in which to refrain from doing so. There are, however, cases in which new pattcrns appear. This happens i n problem solving, where elements from various con- texts such as prey capture and attack may be used to obtain the reward or surmount the obstacle. With repeated trials a sequence of such actions, con- stituting a new pattern, may be built up. In addition, a number of natural pat- terns require some learning before they are perfected. This is true of the meer- kats’ behaviour towards aerial predators and it frequently applies to prey capture. EIBL-EIBESFELDT (1961) has shown how in the polecat an innate response to chase the prey is combined with learning by experience how to make the effective death bite on the nape of the neck, to produce the final characteristic pattern as a whole. The adaptiveness of the arrangement in these two cases is readily apparent. To provide the animal with a built-in recogni- tion mechanism to cope with every harmless bird or every species of prey that might be met with over the whole geographical range of the species, quite apart from any problems as to how it might have been evolved, would almost certainly require a prohibitively large number of neurones. Natural selection has produced a much more economical solution: a generalised escape response to any aerial object above a certain threshold size and a general pursuit of any running object below a certain size, coupled with appropriate learning by experience.

39‘

600 R. F. EWER

Discussion The observations which have been made on Suricata suricatta show that

in this mammal patterned behaviour is as important as in any other vertebrate group. Since none of the animals studied was isolated from birth, it is not possible at this stage to say that all the patterns recorded are fully endogenous, but since they appeared in identical fashion in animals isolated at a few weeks old and since many of them were shown by the young without their having seen the parents behave in the same way, it seems clear that few of them can have owed much to parental example. Furthermore, it would seem that the types of interpretation which have been so fruitfully used by LORENZ and his school in dealing with the behaviour of other vertebrates can equally well be applied here: for instance, displacement behaviour occurs and certain patterns would seem to be most easily understood as being derived activities, having evolved by elaboration of patterns whose normal significance is another functional context.

It is, however, in relation to language that the most interesting points emerge. It is a commonplace to say that in animal language an utterance is not an objective statement about an external situation, but, like other forms of behaviour, a manifestation of the animal’s reaction to that situation and that the sounds made frequently come to have signal value intra- or sometimes inter-specifically. Moreover, both the sounds uttered and the responses made to them by conspecifics are frequently not learnt but endogenous. In etho- logical terms, the sounds act as releasers for corresponding endogenous pat- terns. Now one of the characteristics of releasers of unlearnt responses is that they are generally very simple: they do not comprise everything within the sensory compass of the responding animal, but instead a relatively small num- ber of very distinctive attributes; for instance, the male robin’s threat display does not require the presence of a rival male to release it, a bunch of red feathers is sufficient. One might therefore expect the same sort of simplicity to apply to vocal releasers. Meerkat language has provided two cases which appear to exemplify this principle. The “pseudocall” t o which the young responded so instantly was not an imitation of the animal’s own contact keep- ing sound, but an abstraction of some of its most obvious characteristics. Simi- larly, general alarm barking was evoked by such unnatural sounds as those made by the typewriter and the egg beater. The resemblance of these sounds to any meerkat utterance is slight. They have, however, the common characte- ristic, which they share w;th the “cross noise”, of being harsh and coming in rapid succession and this is sufficient to release a response. In these two cases it therefore appears that the releaser to which the meerkats are responding is not the call of a conspecific in its entirety, but a few of the most obvious cha- racters of the call.

Clearly in order to find out whether this interpretation is correct and, if so, how generally it may apply, a sound spectrographic analysis is necessary. The various cries must first be analysed and then, by producing suitable par- tial imitations, i t should be possible to dissect away the inessentials and find out which are the factors that have signa1,value in each type of utterance and which are irrelevancies or incidentals. In this way a “skeleton” of the language of a single species could be made out. A series of such skeletons might then provide the basis for a comparative linguistic study, for clearly a comparison based on characters of the languages other than those to which the animals are actually responding is unlikely to be very illuminating. The fact that conta- gious barking amongst dogs spreads to involve the meerkat suggests that such an approach may prove fruitful.

The Behaviour of the Mcerkat, Swricata suricatta (Schreber) 60 1

That behavioural characters may be extremely useful in taxonomy is now widely acknowledged, but such characters will not necessarily be equally useful in all types of taxonomic problems. A taxonomist is faced with two comple- mentary sorts of task: on the one hand he must draw distinctions and be able to separate closely similar species; on the other, he must unite related species into natural groups at the higher levels of classification in such a way as to represent as fully as possible their genetic propinquity. Since behaviour and structure are functionally interwoven and have evolved together under the directive force of natural selection it might seem that they ought to be equally applicable to any sort of taxonomic problem. This, however, need not be the case, for two quite different sorts of reason. As has been more fully elaborated elsewhere (EWER 1960) there are grounds for believing that behavioural changes will often take the lead in evolution, both because the adaptive value of an animal’s organs is decided by how it uses them and because behaviour has so much plasticity in relation to the immediate environmental circum- stances. From this it follows that where the problem is one of distinguishing species which have only recently become separate, behaviour is likely to be extremely useful. This is, in fact, the case: MAYR (1958) gives a number of examples where a behavioural difference separates with ease species that are difficult to distinguish structurally. On the other hand, when it comes to the question of dealing with the higher taxonomic categories, behaviour has attri- butes which may make it less useful than structure. Relatively simple techni- ques of dissection and sectioning are sufficient to allow us to apply the rule of relationships to assist in deciding whether two structures are homologous or not. In the case of behaviour the neural inter-relationships of any particular pattern are much more difficult to determine: we rarely know enough to decide whether two similar patterns have the same neural basis; we do not yet even know how reliable such similarity may be as an index of behavioural homology. On behavioural grounds alone, it may therefore be very difficult to decide whether similar patterns are homologous or analagous. Because behaviour is, as mentioned before, so directly adapted to the immediate environmental circumstances, analogies must be expected to be common when- ever there is similarity in mode of life and, conversely, some patterns will vanish without trace when there is a change in mode of life. Nevertheless, if there is no strong selective pressure to alter them, genetically controlled be- havioural characters should be no less phylogenetically stable than anatomical ones and even if their value Droves more difficult to asses, this is no argument for neglecting them in systematic studies.

Bearing these limitations in mind, we may now see what light is thrown on viverrid taxonomy by our present knowledge of their behaviour. Table 3 summarises the information we now possess on five species, and in Table 4 the patterns common to them all are listed. From the latter it will be seen that apart from “sitting up” and using the claws to tear prey, both of which are closely related to anatomical charac- teristics and are not restricted to viver- rids, the common patterns are ones that are extremely widespread amongst the

Table 4. Patterns shown by all 5 Viverrids

Scratching with hind leg Toilet nibbling with incisors (fleaing) Toilet licking Following moving prey Ambush posture Use of claws in tearing up large prey Growling Belly u p defence Bite snapping Sitting u p posture

602 R. F. EWER

Herpestes edwardsii

Table3. Patterns of behaviour shown in various viverrids. The da ta for the species othet than Suricata are taken from DUCKER (1957, 1960) and RENSCH & DUCKER (1959)

Mungos mungo Behaviour

Method of climbing down Sitting up postures

High sit Low sit Lazy sit

Sleeping posture

Turning round before going to sleep

Long stretch’)

Murid type walkstretch C a t type arch- stretch Stretch accom- panied by yawn Claw sharpening

Rigid toilet ritual Scratching with hind foot Incisor nibbling (fleaing) Toilet licking

Face washing with fore paws Tooth cleaning with claws Social grooming

Insects etc. dug out of soil Scratching a t crevices Snails accepted as food Shelled foods broken open

Moving prey followed Prey stalked Orientation in attacking snakes and lizards “Embracinx” of large P!eY2) Neck bite Death shake

Sairicntn siiricnttn

Backwards

+ + 4-

Curled up dorso- vcntrally

-

Progressive and simul- taneous

-

-

-1- -

-

+ +

i (minor importance)

-

+ + With claws

+ -I-

By biting only

-t -

To move- ment only

? Sometimes +

Backwards

- + Curled u p dorso- ventrally

-

- Simul- taneous

-

_ _

? -

-

+ + + -

+ ?

With claws

-t

- ?

-t -

To move- ment only

+ Sometimes +

Backwards

- + ? -

-

Simul- taneous

-

-

? -

-

-1-

-1- -t

-

-t ?

With claws

+ +

By bit ing , vertical o r backward throwin::

-t -

?

- Sometimes +

Viwerriciila indicn

Head first

- + -

Curled on side

-1-

-

- I t

i- t

t

- ?

With snout

- -

?

+ -

?

- + -

Genetra srrahelica

H e a d first

- +

Curled on side

-

+ Progrcssivc

+ + ?

-1-

-

-1-

-1-

-1-

-1-

- -I-

Wirh snout

- -

?

+ + ?

- ? -

Thc I3ehaviour of the Mccrkar. Swicata suricnifa (Schrcbcr)

B c hav iou i

U s e of claws in tcaring up large prey I’rcvcntion of food theft Playing with PrcY Grow 1 i iix Spitting H issi iig Pilocrcction

Archcd back t h rca t

Ambush posturc

I3clly up dcfcncc posturc Bitc-snappiiig3)

Back turnins to c 11 c I11 y 1 nh ib ired biting

St i 8-1 cg g cd rock

Malc m n r k i n ~ by wiping ana l glands Malc niicturi- tion pose Neck hitc used in copulation Female hcld with fore paws during copuln- tion

Suckliii: posturc 0 f fcma I c Carrying of young

Young “trcad” m a tcr n a 1 niani- mary gland with fore paws

Suricata suricattn

-t

Turn away

-1- i-

-

-

General

S I igh t 1 y posterior1 y tiisplaccd Seen only i play

-t -t (not ver marked) Defence an attack Chin and check rubbc + On projcct- ing and flat surfaces Leg cockcd

I n prclimi- narics only

+ (i) Crouched ( i i ) Belly LI l3y neck or head or by back

-~

-t ~

I n “lonz stretch” thc DOS

-- Herpcstcs cdwartisii --

-I-

Turn away

-1- -1- ? -

Gcncral

Postcriorl y displaccd

i-

-1- -t

Dcfcncc only Top of hcnc rubbed + ?.’

On projcct- ng surfaccs on ly

?

-

-1-

?

I3y back

?

‘n adooted i --

Mungos mungo

?

Turn away

+ -t- ? i-

Gcncr a1

Postcriorl y displaced

-I-

I- - t-

On project- ing surfaces on ly

?

3

?

?

Viverriculu iridica

-1-

Turn tow a rd s

? -1- - 1 - -1- ?

-

-1-

-1- -1.

On project- ing and flat surfaces

?

?

?

~~

iilaterallv svmnictrical. Thc

603

Gcnetta suahclica

-I-

I n d c fi n i tc

? -1- -1- +

Mane and tail only C a t liltc

-1-

i- i-

I l u r i ng nioiin t i n g

On side

By back

-t-

3re and h ind , , legs may ci thcr b e simultaneo&ly cxtcndcd or stretching may start with extension of the fore limbs and pass progressively down the body to the hind limbs.

I n “walk stretch” (first decribcd in Muridac by EIBL-EIBESFELD 1953) stretching is asymmetrical, one fore limb and the diagonally opposite hind limb being cxtcnded.

I n arch stretch all four limbs arc hcld vertically and the back is stretched by throwing it into an arch, much resembling the threat arch.

2, DUCKER (1957) notes that when given large prcy Herpestes will grip it firmly in thc fore paws (embracing) before attempting to kill .

:I) Uitc-snapping nicaiis that the animal whcn threatening makes snapping bites towards thc cncniy, without carrying the attack honic and inflicting a gcnuinc bite.

d, KIPLING (1894), i n his story about a n Indian niongoose, gives a brief dcscription of a gait apparently closely rescnibling stiff-lcggcd rock. While this can hardly be taken as a scientific study, KIPLING’S obscrvarions on animals are often vcry accuratc and i t is difficult to imag ine that such a gait would have bcen invented if it did not rcally exist.

604 R. F. EWER

Carnivora. In fact, i t is virtually impossible to diagnose the Viverridae on behavioural characteristics alone. This is in agreement with the ideas of the status of the family which have been arrived a t on structural grounds. The Viverridae are generally regarded (see, for instance, SIMPSON 1945) not as a closely united group comparable with the Felidae or Hyaenidae, but rather as a sort of residuum of the primitive feloid stock, comprising all the groups which have not become sufficiently differentiated to be accorded separate family rank.

A comparison of the three Herpestinae, Suricata, Herpestes and Mungos, with the Viverrinae, Viverricula and Genetta, gives a different (Table 5). The two subfamilies can be clearly and easily separated y be- havioural characters and the Herpestinae form as distinct a group behaviour- ally as they do structurally. Unfortunately Genetta and Viverricula both

Table I . Behavioural differences between Herpestinae and Viverrini

gicture

Her pestinae Viverrinae

Climb down backwards .................... Forwards ”Sleep curled up vertically . . . . . . . . . . . . . . . . . . laterally Face not washed . . . . . . . . . . . . . . . . . . . . . . . . washed Teeth cleaned with claws .................. not Claws not sharpened ...................... sharpened Murid type walk-streth absent . . . . . . . . . . . . . . Food removed from soil with claws . . . . . . . . with snout Crevices investigated by scratching . . . . . . . . . Death-shake of prey present . . . . . . . . . . . . . . . . Turn away from food thief . . . . . . . . . . . . . . . .

present

not

absent Turn towards or indefinite

“Arm grip used in copulation .............. Arm grip not used

’> N o t mentioned by DUCKER in M u n g o s , but probably present.

belong to the Tribe Viverrini, and we have not got sufficient information about representatives of other tribes within the Viverrinae to know how much behavioural diversity exists within the latter. Within the Herpestinae SIMPSON places Suricata by itself in the tribe Suricatini, separate from the Herpestini. Behaviourally there is no justification for this: the resemblances between Suri- cata and Herpestes are extremely close, no less so than between Herpestes and Mungos. Turning again to the Viverrini, DUCKER (1957) records that in Genetta both purring and a cat-like “miau” call exist. In addition the pattern of face washing is very similar to that of a cat and the typical cat-like arched back stretching occurs. It is difficult to believe that these similarities are con- vergences directly related to a particular mode of life; they suggest rather that Genetta may be descended from that branch of the early feloid stock which gave rise to the Felidae.

MANTON (1959) has emphasised that to understand the structural pecu- liarities of a particular group it is necessary to relate these to the “habits of life”. CULLEN (1957) and ALEXANDER (1962) have pointed out that the same is true of behaviour. Thus a full knowledge of any species requires a synthesis of the three inter-related components, mode of life, bodily structure and be- haviour, a point stressed by TINBERGEN (1959).

The Behaviour of the Meerkat, Suricata suvicatta (Schreber) 605

In Suricata the general body form with short limbs, strong back and wide pelvis, the long claws on the fore feet, the reduced pinnae on the ears and the rather coarse fur all clearly relate to burrow living. The predominance of vision is related to a diurnal habit in open country and prey not caught by tracking. The teeth are sharply cusped, without specialised carnassials. They are adapted to chopping up insects, which they do with great efficiency, but are less servicable for dealing with large prey and the long claws are used to assist in tearing up this type of food. The snout is pointed, suited for insect catching: licking is not important in feeding and the tongue is so6 and narrow.

Social burrow life in open terrain and method of feeding are the primary factors and i t is in relation to them and to the structural features associated with them, that the various behaviour patterns must be viewed. The short burrow- adapted legs are compensated for, as far as visual range goes, by sitting up vertically and since fast running is not possible a variety of interspecific threat patterns exists. Individual visual alertness and the habit of periodically sur- veying for enemies is accompanied by vocal signalling which will at once attract the attention of a fellow busied in foraging.

Tongue, toilet behaviour and pelage are inter-related. There is no elabo- rate toilet ritual, which the tongue is unsuited to provide and the fur does not require; but to comoensate for this there is an immediate fleaing response to skin irritation and this, in turn, forms the basis for social grooming.

The introduction of the young to solid food provides another example of the integration of behaviour as a whole. A cat kills prey of medium size, large enough to provide a meal but small enough to carry in the mouth and the female does carry prey back to her young over considerable distances. Wolves kill prey larger than themselves, gorge themselves on the flesh and then return to the young and regurgitate (CRISLEK 1959). The meerkat eats insects so small that to carry them back individually to the young would be too time consum- ing; to swallow them for subsequent regurgitation is not practicable either, since collecting a stomach full would take so long that the first would have been largely digested before the last was caught. The solution found involves the behaviour of both mother and young. The latter develop a very strong following response and extreme food envy. They follow the mother at an early age and are ready to snatch the food from her mouth as soon as she permits it.

Back attack and inhibited biting are patterns that have arisen in relation to feeding habits but now function in social life.

A number of patterns are still not fully understood and the details of social organisation will remain unknown until extensive field studies have been made. The information at present available is nevertheless sufficient to illustrate the complexity of the interactions of ecology, structure and be- haviour involved in the biological synthesis referred to by A. V. HILL in the quotation given at the head of this paper.

Summary

Observations have been made on three specimens of the viverrid Suvicata suricdtta (Schreber) kept as domestic pets and on two litters of young born in captivity. Language, gaits and postures are described, together with patterns connected with the following activities: heat regulation; toilet; micturition, defaecation and marking; food capture; attack and defence.

The role played by learning in the responses to aerial predators and to large prey is considered.

R. F. EWER 606

The development of the responses of the young and the behavioural inter- relationships between them and the parents are recorded.

The taxonomic value of behavioural characteristics is briefly considered. The patterns found in Suricata are compared with those known in other Viverridae and the taxonomic implications of these data are discussed.

The way in which mode of life, bodily structure and behaviour i n Suvicatu are harmoniously integrated is outlined.

Zusammenfassung

Drei im Heini gehaltene Stiicke und zwei in Gefangenschafi geborenc Wurfe einer Viverride, Suvicata suricatta (Schreber) wurden beobachtet. Sprache, Gangarten, Haltungen und Verhaltensweisen, Warmeregulierung, Korperpflege, Harnen und Koten, Marliieren, Nahrungserwerb, Angriff und Verteidigung werden beschrieben.

Es wird erortert, welchen Anteil das Lernen an den Reaktionen auf Raub- vogel und grofie Beute hat.

Die Entwicklung der Verhaltensweisen der Jungen und der Beziehungen zwixhen ihnen und den Eltern werden beschrieben.

Der taxonomische Wert des Verhaltens wird kurz erwogen. Die bei Suri- cuta beobachteten Verhaltensweisen werden mit den bei anderen Viverriden bekannt gewordenen verglichen, und es wird besprochen, was daraus fur das System folgt.

Es wird ausgefuhrt, wie die Lebensweise, der Korperbau und das Verhal- ten von Suricata ein harnionisches Ganzes bilden.

Acknowledgements

During much of the time when these observations were made I was re- ceiving grants from the South African Council for Scientific and Industrial Research, for which I would like to record my gratitude. I am much indebted to Drs. A. J. ALEXANDER and P. LEYHAUSEN for helpful and stimulating dis- cussions and to Mr. c. ROCHE for collaborating in making observations on his young Suricata.

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The Bchaviour of the Mccrkat, Suricata suricarta (Schrcbcr) 607

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Berich tigung Auf Scitc 572 mul2 die zehntc Zeilc von untcn n i i t dcr siebtcn Zcile von untcn aus-

gctauscht wcrden.