The leopard is the archetypal solitary cat, spending the majority of its time alone. Even so, leopards are far from being antisocial and maintain constant contact with other members of their species.
Most cats are loners. With the exception of lions, male cheetahs and feral domestic cats (discussed in this chapter), felids do not form complex, life-long social groups. In this, they resemble most species in the order Carnivora; indeed, only around 15 per cent of carnivores form social groups that endure beyond the fleeting courtship required to perpetuate the species. Of the 110 species residing on the cat branch of carnivores, the Feliformia, at least 90 are fundamentally solitary as adults (or thought to be, in the case of some poorly known species). In addition to those cats listed above, only a handful of highly communal mongooses such as suricates, dwarf mongooses and cusimanses, and three clan-living hyaena species (brown, striped and spotted) form enduring social groups. A few other species – the aardwolf and possibly some mongooses from Madagascar – associate in pairs or extended family groups but, in as much as is known of them, only during the discreet breeding season where males temporarily remain with females to assist raising the young.
Cohorts of cats
In discussing the sociality of cats, biologists use a number of generally familiar terms that have specific meanings in this context. A ‘cohort’ is simply a group of animals of the same age class. The adult cohort is made up of animals capable of reproducing, and the most meaningful population estimates are given as the number of adults. Sub-adults or adolescents are young adults capable of surviving on their own. They hunt independently from the mother and, in most species, no longer associate with her at all, though lioness sub-adults usually remain with the pride into adulthood, and sub-adult males linger with their mothers for longer than other cat species before dispersing. Sub-adult cats are too young to reproduce, either because they are not yet sexually mature or they cannot compete with adult cats for access to mates. Cubs or kittens are dependent on their mother and are usually divided into two cohorts. Large cubs have been weaned and travel with the mother as she moves and hunts. Although they are highly mobile and begin making their own small kills during this stage, large cubs are still dependent upon the mother for survival. Small cubs are wholly reliant on the mother for food, shelter and protection. They are left on their own for long periods while the mother forages and she brings food (as milk or meat) to them, or she retrieves them from the den and escorts them to kills when they are slightly older. Naturally, the transition between cohorts can be quite prolonged – for example, from large cub to sub-adult – so it is not always clear where an individual belongs but, transitions aside, each cohort represents a discrete stage in the life of a cat.
A pride of lions, Khwai River, Moremi Game Reserve, Botswana. This pride has representatives from three cohorts – adults, old cubs (at rear) and young cubs (right) – but a single pride may contain individuals belonging to all cohorts at the same time.
Outside the sub-order, there are more examples of sociality among carnivores, but only one terrestrial family, the Canidae, is dominated by group-living species. Large canids such as African wild dogs, Ethiopian wolves, Asiatic dholes and grey wolves have sophisticated and intensely gregarious, large family groups. Smaller species like coyotes, jackals and various fox species adopt a variety of fluid social arrangements usually based on an enduring pair bond between an adult female and male accompanied by ‘helpers’, the grown pups of previous litters. The other caniform families are made up mostly of solitary species. Although exceptions exist – the raccoon and weasel families each include a handful of group-living species among their ranks, and some bear species come together in large, temporary aggregations outside the breeding season – most other caniform carnivores also follow the cat model in living alone.
Although portrayed as solitary, adult female cats spend most of their lives with cubs. One South African leopard intensively monitored for 12 years had dependent cubs for almost 80 per cent of her adult life.
It is important to clarify what it means when a cat is described as solitary. The adults of most cat species live alone but this does not mean they are antisocial. Males and females come together to mate and usually stay together for as long as the female is receptive. Typically, such associations last less than a week but they may occur surprisingly often (detailed in Chapter 4). Revealingly, though, mating is merely the most obvious association in a world full of constant, if fleeting, social contact. Guy Balme has spent thousands of hours in the humid woodlands of KwaZulu-Natal watching leopards, long considered a strictly solitary species, and he has witnessed many interactions between females and males that have nothing to do with sex. Male leopards are tolerant even of cubs they have sired (or believe they have; see Chapter 4) and sometimes ‘visit’ their females and cubs in amicable associations for as long as 24 hours. Additionally, for most of their adult life, all female cats are accompanied by the cubs of successive litters, so while it is true that most felids do not form the lasting, intricate social bonds of a hyaena clan or a wolf pack, cats do not exist in a social vacuum.
But why are permanent social groups so unusual in cats? Surely teaming up and living together holds obvious advantages? A group of cats would outperform a singleton at many crucial survival tasks, for example, killing large prey, defending territory and protecting cubs. In fact, while these advantages are realised in a few circumstances, living in groups carries substantial costs which, for most cats, exceed the benefits. The main determinant is probably food. The advantages of communal hunting do not necessarily translate into more meat for each cat. Surprisingly perhaps, the gains from being able to tackle larger prey or the increased success rate of group hunts (Chapter 2) are quickly eclipsed by the collective demands of feeding multiple mouths. Numerous studies have demonstrated that the most efficient group size for lionesses to maximise their food intake is very small – usually one or two – and competition among the members of a pride at kills can be intense. (The reasons lions form groups are more complex and are discussed later this section.) Such demands are presumably so great that, for most felids, they outweigh even the potential gains sociality yields in defending cubs and territory or other possible benefits.
As with this cheetah feeding on a gazelle lamb, the ability of most cats effectively to meet their needs by hunting a variety of prey types and sizes is part of the reason they do not form groups.
This is less unexpected when one considers how exceptionally well equipped the individual cat is to operate alone. As discussed earlier, all cat species are striking in their ability to kill very large prey (relative to their size) on their own. Morphologically and behaviourally, the cat is a supreme solo hunter. Enormously powerful musculature, hair-trigger reflexes, retractile claws and supple wrists furnish a cat with tremendous control when catching and handling prey; when combined with the delivery of a precisely oriented killing bite by truncated, powerful jaws, a lone lion can overpower an eland, a leopard can kill a zebra or a caracal can take down an impala. By contrast, African wild dogs or spotted hyaenas rely on relatively more robust and less flexible builds to tire prey over long distances, and work in a group that overcomes the limitations of the individual in killing large quarry. A lone wild dog is not physically constructed to wrestle a wildebeest to the ground but a few dogs can dispatch one at least as efficiently as a big cat. So, even though leopards, golden cats or jungle cats might derive some modest benefit from teamwork, each is proficient enough at surviving alone not to resort to this and, indeed, cannot afford to in view of the additional costs incurred.
Lionesses: matrilines and sisterhoods
Lionesses at play in Namibia’s Etosha National Park. Play among adults is assumed to strengthen bonds within the pride, though the idea has never been properly tested; doubtless, lions (and other cats) also play simply because they enjoy it.
There are, of course, exceptions to the rule. Most prominent among them, the lion’s social system is founded on a sisterhood of related females. Lionesses born into the pride usually stay with the group for life, forging a stable social nucleus numbering up to 20 related lionesses from as many as five generations. Within this matrilineal society, lionesses demonstrate co-operative behaviours unique to wild cats, giving birth synchronously and communally raising the cubs (see Chapter 4). Why, of all wild cats, are lionesses the only ones to live in prides?
Part of the answer is because they can. Africa’s extraordinary richness and density of large herbivore species provides enough of a resource base to support the formation of groups in large cats. Yet, that it is possible does not necessarily mean it is the best strategy; as mentioned earlier, in terms of the amount each individual eats, lions would probably be better off alone or in pairs. Group living seems particularly difficult to reconcile given that an individual lion is capable of killing all but the very largest prey species. In fact, this provides a further piece of the solution. In open habitats where visibility is great, a large kill is a liability; it is impossible to finish off quickly, difficult to hide and is visible to competitors from afar. A single lion can be displaced from a large kill by competing carnivores superior in numbers or size (and recall from Chapter 1 that lions evolved in a rich carnivore guild with almost twice as many species as today, including all modern species as well as three large sabretoothed cats, and at least two extinct large hyaena species). When the odds of losing a kill are very high, better to share it with relatives who will help to defend it and, by reducing their losses to kleptoparasites, perhaps even increase their chances of surviving and raising cubs related to the hunter.
A pride of leopards?
At first glance, the same suite of conditions that biologists believe promoted sociality in lionesses (see main text) also applies to other large cats that share lion habitat – leopards and cheetahs. Both species are found in open habitats and both can kill large prey. Yet the females of these species are always solitary; why is it that there is no such thing as a pride of leopards or cheetahs? A closer look at their ecology reveals that both species are different enough from lions for sociality simply not to make sense. While both species are capable of making large kills, they normally prey upon animals their own size or smaller. Leopards haul their kills away from competitors or prefer denser woodland areas within the savanna mosaic, while cheetah females rarely make kills so large that they cannot drag them into cover and finish them off in a day; although both lose kills to competitors, neither has the lioness’ persistent problem of defending very large, very obvious carcasses. The risk of infanticide is probably also less; it occurs in leopards but likely at lower rates than in lions, and it may not occur at all in cheetahs (see Chapter 4). For the females of both species, there is simply no compelling need powerful enough to overcome the costs of communal living and, like all other female cats, remaining solitary is still the most effective survival strategy.
These lions in Kenya’s Masai Mara National Reserve enjoy good hunting year round. In the wet season, lions have access to high densities of non-migratory prey species such as buffaloes, warthogs, topis and hartebeest. With the seasonal arrival of over a million wildebeest and zebras in July–October, they switch their diet to concentrate almost exclusively on the migrants.
Indeed, enhancing the survival of cubs was probably just as important as retaining kills in driving the development of the pride. Groups of females represent an extremely attractive resource to males and, just as with large kills, are likely to attract a great deal of attention in open habitat. As incipient sociality grew among the ancestral female lion on the open woodlands of East Africa, so too did the risk of infanticide, the killing of their cubs by intruding, unrelated males (detailed in Chapter 4). Banding together held the further advantage that females could better defend their cubs from foreign males. Although a single lioness would have little hope against a male lion, even a pair of lionesses is capable of formidable opposition that can deter an infanticidal male. Serengeti researcher Craig Packer has even recorded single adult males killed by groups of lionesses in defence of their cubs.
So, in summary, the open woodlands where (presumably) lion sociality arose not only supported enough large prey to enable lionesses to be social, but essentially mandated it. The evolution of the pride appears to be the lion’s answer to surviving in an acutely competitive environment where the stakes were cubs and kills. Their enhanced defence was enough of a factor to outweigh the disadvantages that continue to promote a solitary lifestyle in most other cats (including those that live in similar open habitats where one might expect sociality to emerge; see text box ‘A pride of leopards?’, page 87).
Fascinatingly, the only other cats known to form female groups are semi-wild domestic cats living under analogous circumstances. Females living in colonies around docks, boatyards and farms often enjoy access to rich patches of food in the shape of handouts or dumps of fish and animal offal, essentially the scaled-down equivalent of large carcasses. Reaching high densities under such artificial provisioning, female cats are exposed to the same evolutionary forces that promote sociality in lionesses, and their social response is almost identical. They form tight-knit matrilines of related females that enjoy enhanced access to food, synchronise their oestrous periods, den together, suckle one another’s kittens and jointly defend their litters from infanticidal males. Revealingly, such conditions do not occur in the wild for the domestic cat’s progenitor, the African wildcat, and female wildcats adhere to the solitary female model.
Male coalitions
Given that a single lion holds little hope of gaining territory, the pressure on loners to form coalitions is intense. In the Serengeti-Mara ecosystem, duos of unrelated males are more common than related pairs.
But what about the males? Only two species of cats, the lion and cheetah, form enduring alliances between males, which are called coalitions. In both species, coalitions are typically made up of males with close genetic ties. This is especially so for cheetahs, where coalition members are usually brothers belonging to the same litter. Related males from a litter usually stay together when they disperse from the mother (see Chapter 4), leading to most coalitions numbering two or three, and never more than five. Given that a number of litters usually grow up together in a lion pride, membership of lion coalitions is somewhat broader than in cheetahs, and coalitions are larger. As many as nine (but usually two to five) brothers, cousins, half-brothers and so on contribute to their make-up.
Although most coalitions consist of related individuals, it depends on the size of the group. If a male has few or no male relatives, he is more likely to seek out partnerships with unrelated companions. Among the lions of the Serengeti National Park, coalitions of four or more males are always related. By contrast, over 60 per cent of male pairs consist of unrelated individuals and half of all trios consist of a related pair accompanied by an unrelated male. Similarly, as many as 30 per cent of all Serengeti cheetah coalitions contain at least one unrelated member. Most mixed coalitions are pairs of unrelated loners that have teamed up, but single males sometimes join a related pair and occasionally a singleton is accepted by a trio of brothers. Clearly, the reasons for forming groups are compelling for the males of both species. Not surprisingly, it is all about defending territory and the females that go with it, as will be seen in the next section.
Land use: home ranges, territories and time-share
Two female leopards in a clash over territory, Sabi Sands Game Reserve, South Africa. Although fatal fights between female cats of the same species occur less often than among males, it is recorded occasionally in lionesses and leopards.
An adult male leopard, killed by a rival male with a single, devastating bite to the neck, Phinda Game Reserve, South Africa. Few male cats (of all species) reach old age. Most will perish as a result of violent clashes with conspecifics, other carnivores or people.
All cats, females and males, need to secure sufficient resources for two basic requirements: survival and reproduction. Important resources for cats include a wide variety of features in the landscape – water, cover, den sites, refuges from competitors and predators, observation points, game trails and so on – but underpinning all is the availability of food. Female cats display the most straightforward manifestation of addressing this need. Carnivore biologist John Seidensticker fittingly describes adult females as ‘contractionists’: females occupy the minimum area required to provide for themselves and their cubs. While access to water and den sites is crucial for female cats of most species, their spacing patterns are dictated primarily by qualities of their prey: its size, movements, distribution in the landscape and how quickly and frequently it is replenished.
In general, where prey is plentiful, distributed evenly and is stable (meaning that populations fluctuate little), females are able to establish small, exclusive home ranges that overlap little with other female ranges. Where prey is meagre, unevenly distributed or undergoes large fluctuations due to seasonal change or migratory movements, female ranges are more likely to be larger and less exclusive, with more overlap. Depending on prevailing conditions, females of the same species may display both tendencies, or rather, a continuum of tendencies in which these are merely the two extremes. So, for example, the average range size of female leopards in the well-watered, game-rich woodlands of central Kenya is only around 17 square kilometres but climbs to 188 square kilometres in arid northern Namibia where prey is sparse. Overlap in the ranges between unrelated females in the Kenyan study was almost nonexistent whereas it averaged 42 per cent for females in Namibia.
If food dictates how females organise themselves, the spatial patterns of males are shaped by another primal need – reproduction. Males are most interested in increasing their access to as many females as possible so they tend to be ‘expansionists’; they expand the area they use beyond that set by their feeding needs in order to maximise the number of females they encounter. So male spacing patterns are determined chiefly by those of the females. Where females maintain small, densely packed ranges, males are able to establish ranges that encompass a number of female areas and that overlap little with other males. Where females occupy large ranges and live at low densities, male ranges are likely to be much larger and less exclusive. Returning to the leopard example, central Kenyan males have ranges averaging 37 square kilometres with little range overlap, compared to ranges of 451 square kilometres with 26 per cent overlap for Namibian males.
Whatever the resource, food or females, all cats attempt to defend them from conspecifics (with the exception of female cheetahs – see below). Until now, the discussion here has focused on ‘home ranges’ which simply refers to the area containing all the resources that a cat needs to survive and reproduce. However, as we have seen with the comparison between Kenyan and Namibian leopards, cats attempt to maintain exclusive use of their home ranges where conditions permit; in other words, they are territorial. Where possible, most cat species defend their home range from members of their own sex and their range is more accurately described as a ‘territory’. Territory holders exert considerable effort in curtailing intrusions, primarily by announcing their presence to avoid conflicts (see the next section) but, occasionally, clashes over turf can be fatal. Males of the three big cats – lions, leopards and cheetahs – are known sometimes to kill unrelated intruders in fights, and similarly, fatal fights are known among lionesses and female leopards. Other than among female cheetahs, it is likely that such clashes occur from time to time in all African cats but, so far, few have been observed among the smaller species.
The critical advantage in being a territory holder is reproductive. For female cats, reproductive success is closely linked with access to food. The more reliable a food source or the more easily it can be secured, the greater the likelihood that a female cat will raise her cubs to independence. The point of female territoriality is to reduce competition for food and so improve the chances that her cubs survive. Precisely the same principle applies for males, though, of course, the resource for which they are competing is the female. Improving reproductive success for males means mating with as many females as possible while also eliminating competition from other males. So the upper limit of a male’s territory is defined by the area he can effectively defend from competitors.
As discussed in the previous section, male cheetahs and male lions are unique among cats in achieving this by force of numbers. The stronger the coalition, the more effective the defence of an area and its females. If a single male is to have any chance of breeding, he needs to win a territory, a near hopeless task on his own if the competition is in pairs and trios. Among Serengeti cheetahs, for example, coalitions are about six times more likely than a loner to acquire a territory.
For singleton lions or cheetahs, teaming up with unrelated males is the answer, though it carries the cost of sharing females with an unrelated companion. The consequence is that some of ‘your’ cubs will not be related to you. If, however, your male relatives are your companions, you will be related to all of the cubs sired, even if you yourself never have a chance to mate. Indeed, in larger lion coalitions comprised only of relatives, some males never successfully breed. They act essentially as non-breeding helpers to their breeding brothers and cousins, boosting the ability of the coalition to defend females and increasing their own genetic output via nieces and nephews. So, for a male lion or cheetah, the best strategy is to team up with male relatives. Only when they have few male relatives or, especially, none at all, do they form alliances elsewhere. Surprisingly perhaps, in both lions and cheetahs the degree of co-operation between coalition partners is not affected by their relatedness. Whether brothers or entirely unrelated, their bonds are extremely close and their behaviour towards one another is virtually indistinguishable.
For all the apparent ‘rules’ of spacing among cats, males or females, absolute exclusivity is almost certainly an elusive prize. The conditions that foster small, exclusive ranges are uncommon and even where they exist, it appears that most cats tolerate at least some sharing. Except for the very smallest ranges – those of central Kenyan leopards, perhaps – it is essentially impossible for a cat to maintain absolute control over its range. Even the most dominant individual cannot be everywhere at once and besides, it is likely to be surrounded by closely matched rivals that are best avoided, even if they occasionally overstep the territorial boundary.
Shared land tenure
Coalitions of cheetahs are more likely than loners to acquire a territory but, surprisingly, there is little evidence for longer tenure. Among Serengeti males, singletons that managed to establish a territory occupied them for the same period as coalitions, about four years.
Female leopards (and probably those of most solitary felids) retain their territories for life. It is still unclear how female cats accommodate territorial overlap from successive grown daughters throughout their reproductive lives; presumably, a threshold is reached in which some daughters are forced further afield.
The resulting dynamic pattern of land use is better described as ‘shared land tenure’. In this system, the core area of the territory is typically inviolate and always used by one resident alone, but occupancy of the peripheries is more fluid. Neighbours share the edges but actively avoid one another in the overlapping areas in a time-share system based on the ‘dear enemy’ relationship: that is, it is better to tolerate limited overlap from a known rival who also ‘agrees’ to tolerance rather than attempt to overthrow it, risking both severe injury and its replacement by a more powerful, less tolerant newcomer. Maintaining the status quo means that a resident avoids a particular portion of overlapping turf if its neighbour is there. A week or a month later, the situation may be reversed.
Most cats are not yet sufficiently studied to know the degree to which the land tenure system applies but in the ‘classically’ territorial leopard, intensive study is revealing that overlap between neighbours is usually considerable. In northern KwaZulu-Natal’s Phinda-Mkhuze ecosystem, Guy Balme and I have radio-collared every adult male in our study area to determine the degree of time-share (we know when we have successfully caught all the leopards present by remote camera-trapping). Despite the area supporting abundant resident prey, therefore lending itself to small exclusive ranges, none of the 14 males collared to date maintains an exclusive territory. In fact, in the most extreme case, one adult male has his entire territory within the boundaries of another. Such overlap is not unique to males. Indeed, female leopards are more likely than males to share resources with neighbouring females (in part, because they are more likely to be related; see Chapter 4) but, like males, never at the same time. Different females occasionally even use the same kopjes, caves or bushes to bear their cubs, though never simultaneously. In the game-rich southern Kruger National Park, female leopards share an average of 18 per cent of their ranges, and similarly, two radio-collared females in the rainforest of Côte d’Ivoire’s Taï National Park shared about one-sixth of their ranges. And we have already seen how overlap increases where resources are more thinly spread, as for female leopards in Namibia.
It is likely that the shared land tenure model applies to most solitary cats, at least to some degree. Three adult male blackfooted cats in Sliwa’s study had territories that overlapped by 12 to 14 per cent, while resident females overlapped by an average of 40.4 per cent. Similarly, three male caracals living on farms in central Namibia overlapped by an average of 19 per cent. In Israel, three radio-collared male sand cats with overlapping territories took turns using the same dens and burrows.
Of all wild cats, overlap is greatest among female cheetahs. In fact, cheetahs are exceptional among the Felidae in that the females do not establish a territory. Female cheetahs roam over vast areas which are never actively defended except for rare aggression towards other females if they venture near very young cubs in the den. Female cheetahs display the most extreme version of the time-share model, and do not maintain even an exclusive core region as do other female cats. In the Serengeti, up to 20 females use the same area and clashes between them are essentially non-existent. Female cheetahs go out of their way to avoid other females they see in the distance or simply ignore them. The home ranges of female cheetahs can be huge. On the Serengeti short-grass plains, ranges are rarely smaller than 395 square kilometres and sometimes exceed 1 200 square kilometres. In Namibia, female home ranges are even larger: eight females radio-tracked by Laurie Marker in central Namibia covered areas ranging from 554 square kilometres to an astonishing 7 063 square kilometres. The average range size for Marker’s Namibian females was over 2 100 square kilometres.
The vast ranges of female cheetahs pose a problem for the males. As we have seen, male cheetahs do attempt to establish a territory but their females do not play by the normal felid rules. Female ranges are too large for male cheetahs to encompass and defend, as occurs among the males of all other species from black-footed cats to lions. Instead, male cheetahs exploit the extensive overlap between female ranges and adopt a unique variation on the male territorial strategy. Rather than attempting to defend entire female ranges, they focus on the most productive areas within them. Males create small, defendable territories around female ‘hotspots’, discrete areas rich in resources – prey, den sites and water – that attract female cheetahs. Females spend more time in the hotspots than outside them, so the best located territories may see a succession of females as they pass through the area.
There is one final twist in the social life of the cheetahs: the non-resident male or ‘floater’. Floaters do not hold a territory and wander over large ranges, similar in size to those of females. Young males or old ones expelled from their territories have no choice but to float, but some coalitions of prime males appear to adopt this lifestyle by choice. In terms of the reproductive benefits, floaters might encounter as many or possibly even more females by searching for them over large areas, rather than staying put on a small territory and waiting for females to visit it. The genetic studies have not yet been undertaken to say which strategy yields the greater rewards in terms of the number of cubs sired, but perhaps both are equally effective. The cheetah’s flexible social system illustrates that no rule is set in stone. The social systems of all cats demonstrate considerable elasticity and, as science continues to investigate them, more variation will doubtless be discovered.
The lion’s mane
Unique among cats, the mane of the male lion has been thought to have three possible functions. First, to act as body armour, protecting the vulnerable neck and throat against attacks from other males; second, to make the bearer appear more intimidating to a rival; and third, to attract lionesses. These theories were put to the test by Serengeti researchers Peyton West and Craig Packer. They found no evidence that the mane provided a shield against attacks; fighting males do not preferentially attack the neck and shoulders, and wounds there were no more or less harmful than wounds elsewhere on the body. Besides, all large cats are armed for lethal attacks but only lions have manes. However, West and Packer’s results lend support to the second and third theories. Using two life-size lion dummies with interchangeable manes, they tested the reactions of males and females to various combinations – dark manes versus light, and long ones versus short. They found that lionesses always preferred dark manes regardless of length, while males avoided dark manes and, to a lesser degree, also avoided long manes.
We know that dark-maned lions are older and have higher levels of testosterone, making them more aggressive fighters and dominant on kills; they are also better nourished. Short manes indicate youth and poor health (injured or poorly fed males often lose some mane) while light-coloured manes point to lower testosterone, hinting at a reduced ability to fight or compete. In other words, by assessing mane colour, lionesses select mature, healthy, aggressive individuals that will excel in defending the pride against incursions from other males. Males, on the other hand, avoid those individuals because they are the most formidable opponents in a fight. The lion’s group-living behaviour is probably the reason it is the only felid possessing a mane. Living in close contact with many conspecifics provides constant opportunities for lions to assess one another. In such a rich – and risky – social environment, the mane is an invaluable signal by which other lions, female and male alike, make their decisions about which males to approach and which to avoid.
Territorial maintenance: communication among cats
An adult female leopard urine-marks her range, proclaiming territorial rights. As her large cub (in the background) approaches independence, her scent marks will change subtly to herald her return to oestrus.
Cats marking their territory: deposits from scent glands on the cheeks, chin and between the toes enhance the territorial and reproductive messages left by spraying and defecation.
To maintain spacing between one another, cats engage in a variety of territorial behaviours which advertise the presence of a resident. In the cat’s world, such advertisements play a dual role, depending on the audience. To a familiar conspecific or a potential mate, they help maintain friendly contact, and ensure that males and females locate each other during the relatively brief opportunities when the latter are receptive (see Chapter 4). To a rival, though, the same behaviours act as a warning, proclaiming ownership of an area. Cats are so well equipped to inflict serious injury that it is better for all parties to avoid unexpected encounters. They do so by maintaining a constant network of communication based on scent marks and long-distance vocalisations.
Territory holders tirelessly mark their range with urine and faeces. The rates of such marking can be prodigious. In only 65 minutes of following a territorial male leopard, during which time the cat was never out of sight, Guy Balme observed 17 sprays, six scrapes and five territorial calls. Male servals in Ngorongoro Crater spray at an average rate of 46 times an hour or about 40 times for every kilometre walked. Male black-footed cats normally scent mark around 10 to 12 times an hour but, like all cats, they escalate the rate enormously at critical times; one of Alex Sliwa’s radio-collared males marked 585 times in one night on detecting a sexually receptive female in the area. Doubtless, his efforts helped the pair locate each other (they were together and mating the next night), but such assiduous marking also serves unambiguously to announce his interest to potential rivals. Female cats of all species typically mark at lower rates than males – for example, 20 times per hour and 15 times per kilometre for female servals – but they intensify their efforts when in oestrus.
Cats also mark with saliva and deposits from glands on the cheeks and chin, which is why they rub their faces against key features like trees, stumps and rocks, often drooling in the process. Glands between the toes and at the base of the tail further contribute to their unique olfactory signature, and residents draw attention to their signposts by raking the ground with the hind feet, creating a territorial ‘scrape’ and by clawing trees with the front feet (which probably also maintains the condition of claws). Scent marks are deposited most often at the boundaries of territories and on conspicuous points throughout, including well travelled paths, large trees, bushes and termite mounds. Faced with a shortage of prominent sites, desert-living sand cats create their own: they scrape together a small pile of sand, and deposit faeces and urine prominently on top of the mound. Biologists are only now developing methods to translate the messages contained in scent marks, but it is clear they reveal substantial information about the owner to conspecifics: identity, sex, age, reproductive condition, ownership of an area and possibly even an update on health. Territory owners repeatedly freshen scent marks to ensure that their declaration of ownership persists; cats can assess the age of a mark and, although it has not been well studied in African species, scent marks appear to be effective for up to four weeks, after which they are ignored.
Both lionesses and male lions roar, but the male’s roar is louder, deeper and more prolonged than the female’s. Experienced human listeners easily discern the difference, so presumably lions can and, indeed, lions are able to recognise familiar individuals by their call.
Reinforcing the message of their scent marks, most cats have long-range calls. Perhaps the best known is the lion’s roar. Carrying for at least eight kilometres to human listeners and clearly more to leonine ones, roaring helps members of the same pride maintain contact and find one another. Without question, the roar also plays a critical role in communicating with strangers. Craig Packer and his colleagues investigated the response of Serengeti lions in an elegant series of playback experiments, in which tape-recorded roars were played through loudspeakers to prides. When the roars of familiar lions were played, the response of listening lions was ambivalent; they sometimes called back or headed towards the calls but often they did not bother. However, when the tape played unfamiliar lions, the response was far less ambiguous. In response to calls by their own sex, both lionesses and male lions immediately began roaring and rushed to repel the ‘intruders’. Intriguingly, though, lions are more likely to respond aggressively when they have numerical and geographic superiority. Lionesses assess how many adversaries are calling (in this study, Packer’s females discriminated between one versus three rivals calling), and are more likely to engage lone aggressors. Similarly, males weigh up numbers at territorial boundaries but largely ignore them deep inside their territories; regardless of numbers, resident males rush aggressively to engage rivals if they have the temerity to roar in the central area of a coalition’s range.
Science knows less about the role of territorial calling in other cats, though basic similarities are probably common to most species. The rasping long-distance call of resident leopards (often called sawing or coughing) can be heard by humans from three kilometres away, and Kruger National Park researcher Ted Bailey was able to distinguish the leopards of his study by their calls, so doubtless leopards can too. Similar to roaring in lions, rasping takes place mainly at night, with surges at dawn and dusk reflecting peaks in activity and movement. Among the smaller felids, the equivalent call is probably the loud, repetitive meowing familiar to anyone living near stray domestic cats. The same call is known from golden cats, caracals, wildcats, servals and black-footed cats, though detailed observations from wild individuals are lacking for all but the last one. The black-footed cat’s startlingly loud, deep meow is repeated up to ten times in quick succession and is mostly heard uttered by males. As for other cats, the calls probably help to maintain spacing between rivals, but importantly, they are most often heard during the mating season when males are looking for females (see Chapter 4). Most unusual of all, sand cats are reputed to utter a piercing, long-range call that sounds like the bark of a small dog. Male sand cats in Israel were seen to head to the tops of hills to repeat this strange call, presumably in an effort to boost their broadcast.
Cheetahs are notable among cats for apparently lacking a territorial call intended to warn off rivals. Although male territory holders are as diligent as any male cat in marking their turf, they do not proclaim its occupation by calling. Cheetahs do have a resonant long-range call known as yipping, but its primary function is to unite the members of a social group during rare separations. The balance of the feline vocal repertoire is used mainly for close and medium-range contact between conspecifics and other species (see text box ‘Felid vocalisations’ below).
Felid vocalisations
At least 14 different types of vocalisations have been described for cats, though no species has them all, and a number of call types have low, intermediate and high intensity variations that sound like quite unrelated calls to the human listener.
Common to all species of cats are hissing, spitting, snarling and growling, used in aggressive or defensive encounters. All cats also share what is termed the main call, although the sound varies greatly among species. In smaller cats, the main call has two major manifestations: mewing for close-range, friendly encounters, and the loud meow and its variants for long-distance communication. The lion is the only cat that lacks a pure main call (the meow) but employs a variation known as the main-call-with-grunt-element, which sounds like a soft moan and is used to call over medium distances. The main-call-with-grunt is also used by leopards, tigers and jaguars. Lions, leopards and jaguars are also the only cats that can roar and grunt, which is their version of the mew. In lions, the grunt is the ‘au-uhh’ sound used to call cubs or pride members.
Unique to the Panthera cats and their relatives, the clouded leopard and snow leopard, are the unusual, close-range, friendly calls known as prusten and puffing, which are made by rapidly blowing air through the nostrils and lips. Prusten sounds like a horse’s snort with a soft vocal murmur, and is not known from any African cat. The equivalent call, puffing (or chuffing), lacks the murmur and is recorded only in lions and leopards; it sounds like a bout of soft, stifled sneezing.
Functionally equivalent to prusten and puffing, gurgling is used by all other cat species in friendly encounters, during courtship and mating, or to appease strange conspecifics. Gurgling varies enormously among and within species, but it generally sounds like a burbling noise, cooing or a prolonged chirrup; the cheetah’s churr call is a high-intensity example of the gurgle.
Only seven species of cats – including caracals, African golden cats and probably servals – are known to wah-wah, used when two animals approach one another. And, finally, purring is known from many species of cats, although none of the big cats is able to purr.
