The Behaviour of the Meerkat, Suricata suricatta (Schreber)
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The Behaviour of the Meerkat, Stcricata suricatta (Schreber)
By R. F. Ewv.i
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 DUCKERS (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. DUCKERS 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. DUCKERS 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 owners 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 ones shoulder.
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 animals 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 ones feet crowing as a sign that one is i n a position malting it impossible for him to climb on ones 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...