The spotted hyena (Crocuta crocuta), also known as the laughing hyena, is a hyena species, currently classed as the sole extant member of the genus Crocuta, native to Sub-Saharan Africa. It is listed as being of least concern by the IUCN on account of its widespread range and large numbers estimated between 27,000 and 47,000 individuals. The species is, however, experiencing declines outside of protected areas due to habitat loss and poaching. The species may have originated in Asia, and once ranged throughout Europe for at least one million years until the end of the Late Pleistocene. The spotted hyena is the largest known member of the Hyaenidae, and is further physically distinguished from other species by its vaguely bear-like build, its rounded ears, its less prominent mane, its spotted pelt, its more dual purposed dentition, its fewer nipples and the presence of a pseudo-penis in the female. It is the only mammalian species to lack an external vaginal opening.
The spotted hyena is the most social of the Carnivora in that it has the largest group sizes and most complex social behaviours. Its social organisation is unlike that of any other carnivore, bearing closer resemblance to that of cercopithecine primates (baboons and macaques) with respect to group-size, hierarchical structure, and frequency of social interaction among both kin and unrelated group-mates. However, the social system of the spotted hyena is openly competitive rather than cooperative, with access to kills, mating opportunities and the time of dispersal for males depending on the ability to dominate other clan-members. Females provide only for their own cubs rather than assist each other, and males display no paternal care. Spotted hyena society is matriarchal; females are larger than males, and dominate them.
The spotted hyena is a highly successful animal, being the most common large carnivore in Africa. Its success is due in part to its adaptability and opportunism; it is primarily a hunter but may also scavenge, with the capacity to eat and digest skin, bone and other animal waste. In functional terms, the spotted hyena makes the most efficient use of animal matter of all African carnivores. The spotted hyena displays greater plasticity in its hunting and foraging behaviour than other African carnivores; it hunts alone, in small parties of 2–5 individuals or in large groups. During a hunt, spotted hyenas often run through ungulate herds in order to select an individual to attack. Once selected, their prey is chased over a long distance, often several kilometres, at speeds of up to 60 km/h.
The spotted hyena has a long history of interaction with humanity; depictions of the species exist from the Upper Paleolithic period, with carvings and paintings from the Lascaux and Chauvet Caves. The species has a largely negative reputation in both Western culture and African folklore. In the former, the species is mostly regarded as ugly and cowardly, while in the latter, it is viewed as greedy, gluttonous, stupid, and foolish, yet powerful and potentially dangerous. The majority of Western perceptions on the species can be found in the writings of Aristotle and Pliny the Elder, though in relatively unjudgmental form. Explicit, negative judgments occur in the Physiologus, where the animal is depicted as a hermaphrodite and grave-robber. The IUCN's hyena specialist group identifies the spotted hyena's negative reputation as detrimental to the species' continued survival, both in captivity and the wild.
Description & appearance
The spotted hyena has a strong and well developed neck and forequarters, but relatively underdeveloped hindquarters. The rump is rounded rather than angular, which prevents attackers coming from behind from getting a firm grip on it. The head is wide and flat with a blunt muzzle and broad rhinarium. In contrast to the striped hyena, the ears of the spotted hyena are rounded rather than pointed. Each foot has four digits, which are webbed and armed with short, stout and blunt claws. The paw-pads are broad and very flat, with the whole undersurface of the foot around them being naked. The tail is relatively short, being 300–350 mm (12–14 in) long, and resembles a pompom in appearance. Unusually among hyaenids, and mammals in general, the female spotted hyena is considerably larger than the male. Both sexes have a pair of anal glands which open into the rectum just inside the anal opening. These glands produce a white, creamy secretion which is pasted onto grass stalks by everting the rectum. The odour of this secretion is very strong, smelling of boiling cheap soap or burning, and can be detected by humans several metres downwind. The spotted hyena has a proportionately large heart, constituting close to 1% of its body weight, thus giving it great endurance in long chases. In contrast, a lion's heart makes up only 0.45–0.57 percent of its body weight. The now extinct Eurasian populations were distinguished from the modern African populations by their shorter distal extremities and longer humerus and femur. The skull of the spotted hyena differs from that of the striped hyena by its much greater size and narrower sagittal crest. For its size, the spotted hyena has one of the most powerfully built skulls among the Carnivora. The dentition is more dual purposed than that of other modern hyena species, which are mostly scavengers; the upper and lower third premolars are conical bone-crushers, with a third bone-holding cone jutting from the lower fourth premolar. The spotted hyena also has its carnassials situated behind its bone-crushing premolars, the position of which allows it to crush bone with its premolars without blunting the carnassials. Combined with large jaw muscles and a special vaulting to protect the skull against large forces, these characteristics give the spotted hyena a powerful bite which can exert a pressure of 80 kgf/cm2 (1140 lbf/in²), which is 40% more force than a leopard can generate. The jaws of the spotted hyena outmatch those of the brown bear in bonecrushing ability, and free ranging hyenas have been observed to crack open the long bones of giraffes measuring 7 cm in diameter. A 63.1 kg (139 lb) spotted hyena is estimated to have a bite force of 565.7 newtons at the canine tip and 985.5 newtons at the carnassial eocone. One individual in a study was found to exert a bite force of 4,500 newtons on the measuring instruments.
The spotted hyena is the largest extant member of the Hyaenidae. Adults measure 95–165.8 cm (37–65 in) in body length, and have a shoulder height of 70–91.5 cm (28–36 in). Adult male spotted hyenas in the Serengeti weigh 40.5–55.0 kg (89–121 lb), while females weigh 44.5–63.9 kg (98–141 lb). Spotted hyenas in Zambia tend to be heavier, with males weighing on average 67.6 kg (149 lb), and females 69.2 kg (153 lb). Exceptionally large weights of 81.7 kg (180 lb) and 90 kg (198 lb) are known. It has been estimated that adult members of the now extinct Eurasian populations weighed 102 kg (225 lb).
Fur colour varies greatly and changes with age. Unlike the fur of the striped and brown hyena, that of the spotted hyena consists of spots rather than stripes and is much shorter, lacking the well defined spinal mane of the former two species. The base colour generally is a pale greyish-brown or yellowish-grey on which an irregular pattern of roundish spots is superimposed on the back and hind quarters. The spots, which are of variable distinction, may be reddish, deep brown or almost blackish. The spots vary in size, even on single individuals, but are commonly 20 mm (0.79 in) in diameter. A less distinct spot pattern is present on the legs and belly but not on the throat and chest. Some research groups (such as Ngorongoro Crater Hyena Project and MSU Hyena Project) often use the spot patterns to help identify individual hyenas). A set of five, pale and barely distinct bands replace the spots on the back and sides of the neck. A broad, medial band is present on the back of the neck, and is lengthened into a forward facing crest. The crest is mostly reddish-brown in colour. The crown and upper part of the face is brownish, save for a white band above both eyes, though the front of the eyes, the area around the rhinarium, the lips and the back portion of the chin are all blackish. The limbs are spotted, though the feet vary in colour, from light brown to blackish. The fur is relatively sparse and consists of two hair types; moderately fine underfur (measuring 15–20 mm (0.59–0.79 in)) and long, stout bristle hairs (30–40 mm (1.2–1.6 in)). European Paleolithic rock art depicting the species indicates that the Eurasian populations retained the spots of their modern-day African counterparts.
The genitalia of the female closely resembles that of the male; the clitoris is shaped and positioned like a penis, a pseudo-penis, and is capable of erection. The female also possesses no external vagina (vaginal opening), as the labia are fused to form a pseudo-scrotum. The pseudo-penis is traversed to its tip by a central urogenital canal, through which the female urinates, copulates and gives birth. The pseudo-penis can be distinguished from the males' genitalia by its somewhat shorter length, greater thickness, and more rounded glans. In both males and females, the base of the glans is covered with penile spines. The formation of the pseudo-penis appears largely androgen independent, as the pseudo-penis appears in the female fetus before differentiation of the fetal ovary and adrenal gland. When flaccid, the pseudo-penis is retracted into the abdomen, and only the prepuce is visible. After giving birth, the pseudo-penis is stretched, and loses many of its original aspects; it becomes a slack-walled and reduced prepuce with an enlarged orifice with split lips.
Distribution & habitat
The spotted hyena's distribution once ranged in Europe from the Iberian Peninsula to the Urals, where it remained for at least one million years. Remains have also been found in the Russian Far East, and it has been theorised that the presence of hyenas there may have delayed the colonisation of North America. The causes of the species' extinction in Eurasia are still largely unknown. In Western Europe at least, the spotted hyena's extinction coincided with a decline in grasslands 12,500 years ago. Europe experienced a massive loss of lowland habitats favoured by spotted hyenas, and a corresponding increase in mixed woodlands. Spotted hyenas, under these circumstances, would have been outcompeted by wolves and humans which were as much at home in forests as in open lands, and in highlands as in lowlands. Spotted hyena populations began to shrink roughly 20,000 years ago, completely disappearing from Western Europe between 14–11,000 years ago, and earlier in some areas.
Historically, the spotted hyena was widespread throughout Sub-Saharan Africa. It is present in all habitats save for the most extreme desert conditions, tropical rainforests and the top of alpine mountains. Its current distribution is patchy in many places, especially in West Africa. Populations are concentrated in protected areas and surrounding land. There is a continuous distribution over large areas of Ethiopia, Kenya, Tanzania, Botswana, Namibia and the Transvaal Lowveld areas of South Africa. During the 1770s and 1780s the species was still widespread in southern and western South Africa, being recorded i.a. on the Cape Peninsula and Cape Flats, and near present-day Somerset West, Riviersonderend, Mossel Bay, George, Joubertina, Gamtoos River, Jansenville, Cannon Rocks, Alice, Onseepkans and Augrabies Falls.
The species dwells in semi-deserts, savannah, open woodland, dense dry woodland, and mountainous forests up to 4,000 m in altitude. It is scarce or absent in tropical rainforests and coastal areas. Its preferred habitats in west Africa include the Guinea and Sudan savannahs, and is absent in the belt of dense coastal forest. In the Namib Desert, it occurs in riverine growth along seasonal rivers, the sub-desertic pro-Namib and the adjoining inland plateau. In ideal habitats, the spotted hyena outnumbers other large carnivores, including other hyena species. However, the striped and brown hyena occur at greater densities than the spotted species in desert and semi-desert regions. Population densities based on systematic censuses vary substantially, from 0.006 to 1.7 individuals per km2. Hunting & food
Unlike other large African carnivores, spotted hyenas do not preferentially prey on any species, and only African buffalo and giraffe are significantly avoided. Spotted hyenas prefer prey with a body mass range of 56–182 kg (123–401 lb), with a mode of 102 kg (225 lb). When hunting medium to large sized prey, spotted hyenas tend to select certain categories of animal; young animals are frequently targeted, as are old ones, though the latter category is not so significant when hunting zebras, due to their aggressive anti-predator behaviours. The spotted hyena tracks live prey by sight, hearing and smell. Carrion is detected by smell and the sound of other predators feeding. During daylight hours, they watch vultures descending upon carcasses. Their auditory perception is powerful enough to detect sounds of predators killing prey or feeding on carcasses over distances of up to 10 km (6.2 mi). Unlike the grey wolf, the spotted hyena relies more on sight than smell when hunting, and does not follow its prey's prints or travel in single file. Small prey is killed by being shaken in the mouth, while large prey is eaten alive.
Spotted hyenas usually hunt wildebeest either singly, or in groups of two or three. They catch adult wildebeest usually after 5 km (3.1 mi) chases at speeds of up to 60 km/h (37 mi/h). Chases are usually initiated by one hyena and, with the exception of cows with calves, there is little active defence from the wildebeest herd. Wildebeest will sometimes attempt to escape hyenas by taking to water although, in such cases, the hyenas almost invariably catch them. Zebras require different hunting methods to those used for wildebeest, due to their habit of running in tight groups and aggressive defence from stallions. Typical zebra hunting groups consist of 10–25 hyenas, though there is one record of a hyena killing an adult zebra unaided. During a chase, zebras typically move in tight bunches, with the hyenas pursuing behind in a crescent formation. Chases are usually relatively slow, with an average speed of 15–30 km/h. A stallion will attempt to place himself between the hyenas and the herd, though once a zebra falls behind the protective formation it is immediately set upon, usually after a chase of 3 km (1.9 mi). Though hyenas may harass the stallion, they usually only concentrate on the herd and attempt to dodge the stallion's assaults. Unlike stallions, mares typically only react aggressively to hyenas when their foals are threatened. Unlike wildebeest, zebras rarely take to water when escaping hyenas. When hunting Thomson's gazelles, spotted hyenas usually operate alone, and prey primarily on young fawns. Chases against both adult and young gazelles can cover distances of 5 km (3.1 mi) with speeds of 60 km/h (37 mi/h). Female gazelles do not defend their fawns, though they may attempt to distract hyenas by feigning weakness.
The spotted hyena is the most carnivorous member of the Hyaenidae. Unlike its brown and striped cousins, the spotted hyena is a predator, not a scavenger; this has been shown since the 1960s. One of the earliest studies to demonstrate their hunting abilities was done by Hans Kruuk, an African wildlife ecologist, and he showed through a 7-year study of hyena populations in Africa that spotted hyenas hunt as much as lions, and with later studies this has been shown to be the average in all areas of Africa. However spotted hyenas remain being mislabeled as scavengers, often even by ecologists and wildlife documentary channels.
Wildebeest are the most commonly taken medium-sized ungulate prey item in both Ngorongoro and the Serengeti, with zebra and Thomson's gazelles coming close behind. Cape buffalo are rarely attacked due to differences in habitat preference, though adult bulls have been recorded to be taken on occasion. In Kruger National Park, blue wildebeest, cape buffalo, Burchell's zebra, greater kudu and impala are the spotted hyena's most important prey, while giraffe, impala, wildebeest and zebra are its major food sources in the nearby Timbavati area. Springbok and kudu are the main prey in Namibia's Etosha National Park, and springbok in the Namib. In the southern Kalahari, gemsbok, wildebeest and springbok are the principal prey. In Chobe, the spotted hyena's primary prey consists of migratory zebra and resident impala. In Kenya's Masai Mara, 80% of the spotted hyena's prey consists of topi and Thomson's gazelle, save for during the four-month period when zebra and wildebeest herds migrate to the area. Bushbuck, suni and buffalo are the dominant prey items in the Aberdare Mountains, while Grant's gazelle, gerenuk, sheep, goats and cattle are likely preyed upon in northern Kenya.
In west Africa, the spotted hyena is primarily a scavenger who will occasionally attack domestic stock and medium-size antelopes in some areas. In Cameroon, it is common for spotted hyenas to feed on small antelopes like kob, but may also scavenge on reedbuck, kongoni, buffalo, giraffe, African elephant, topi and roan antelope carcasses. Records indicate that spotted hyenas in Malawi feed on medium to large-sized ungulates such as waterbuck and impala. In Tanzania's Selous Game Reserve, spotted hyenas primarily prey on wildebeest, followed by buffalo, zebra, impala, giraffe, reedbuck and kongoni. In Uganda, it is thought that the species primarily preys on birds and reptiles, while in Zambia it is considered a scavenger.
Spotted hyenas have also been found to catch fish, tortoises, humans, black rhino, hippo calves, young African elephants, pangolins and pythons. There is at least one record of four hyenas killing an adult or subadult hippopotamus in Kruger National Park. Spotted hyenas may consume leather articles such as boots and belts around campsites. Jane Goodall recorded spotted hyenas attacking or savagely playing with the exterior and interior fittings of cars, and the species is thought to be responsible for eating car tyres.
The fossil record indicates that the now extinct European spotted hyenas primarily fed on Przewalski's horses, Irish elk, reindeer, red deer, roe deer, fallow deer, wild boar, ibex, steppe wisent, aurochs, and woolly rhinoceros. Spotted hyenas are thought to be responsible for the dis-articulation and destruction of some cave bear skeletons. Such large carcasses were an optimal food resource for hyenas, especially at the end of winter, when food was scarce.
A single spotted hyena can eat at least 14.5 kg of meat per meal, and although they act aggressively toward each other when feeding, they compete with each other mostly through speed of eating, rather than by fighting as lions do. Spotted hyenas can take less than two minutes to eat a gazelle fawn, while a group of 35 hyenas can completely consume an adult zebra in 36 minutes. Spotted hyenas do not require much water, and typically only spend 30 seconds drinking.
When feeding on an intact carcass, spotted hyenas will first consume the meat around the loins and anal region, then open the abdominal cavity and pull out the soft organs. Once the stomach, its wall and contents are consumed, the hyenas will eat the lungs and abdominal and leg muscles. Once the muscles have been eaten, the carcass is disassembled and the hyenas carry off pieces to eat in peace. Spotted hyenas are adept at eating their prey in water: they have been observed to dive under floating carcasses to take bites, then resurface to swallow. Reproduction
The spotted hyena is a non-seasonal breeder, though a birth peak does occur during the wet season. Females are polyestrous, with an estrus period lasting two weeks. Like many feliform species, the spotted hyena is promiscuous, and no enduring pair bonds are formed. Members of both sexes may copulate with several mates over the course of several years. Males will show submissive behaviour when approaching females in heat, even if the male outweighs his partner. Females usually favour younger males born or joined into the clan after they were born. Older females show a similar preference, with the addition of preferring males with whom they have had long and friendly prior relationships. Passive males tend to have greater success in courting females than aggressive ones. Copulation in spotted hyenas is a relatively short affair, lasting 4–12 minutes, and typically only occurs at night with no other hyenas present. The mating process is complicated, as the male's penis enters and exits the female's reproductive tract through her pseudo-penis rather than directly through the vagina, which is blocked by the false scrotum and testes. These unusual traits make mating more laborious for the male than in other mammals, while also ensuring that rape is physically impossible. Once the female retracts her clitoris, the male enters the female by sliding beneath her, an operation facilitated by the penis's upward angle. Once this is accomplished, a typical mammalian mating posture is adopted. Copulation may be repeated multiple times during a period of several hours. Both partners usually lick their genitals for several minutes after mating.
The length of the gestation period tends to vary greatly, though 110 days is the average length of time. In the final stages of pregnancy, dominant females provide their developing offspring with higher androgen levels than lower-ranking mothers do. The higher androgen levels – the result of high concentrations of ovarian androstenedione – are thought to be responsible for the extreme masculinization of female behavior and morphology. This has the effect of rendering the cubs of dominant females more aggressive and sexually active than those of lower ranking hyenas; high ranking male cubs will attempt to mount females earlier than lower ranking males. The average litter consists of two cubs, with three occasionally being reported. Males take no part in the raising of young. Giving birth is difficult for female hyenas, as the females give birth through their narrow clitoris, and spotted hyena cubs are the largest carnivoran young relative to their mothers' weight. During parturition, the clitoris ruptures in order to facilitate the passage of the young, and may take weeks to heal.
Cubs are born with soft, brownish black hair, and weigh 1.5 kg on average. Unique among carnivorous mammals, spotted hyenas are also born with their eyes open and with 6–7 mm long canine teeth and 4 mm long incisors. Also, cubs will attack each other shortly after birth. This is particularly apparent in same sexed litters, and can result in the death of the weaker cub. This neonatal siblicide kills an estimated 25% of all hyenas in their first month. Male cubs which survive grow faster and are likelier to achieve reproductive dominance, while female survivors eliminate rivals for dominance in their natal clan. Lactating females can carry 3–4 kg (6.6–8.8 lb) of milk in their udders. Spotted hyena milk has the highest protein and fat content of any terrestrial carnivore. Cubs will nurse from their mother for 12–16 months, though they can process solid food as early as three months. Mothers do not regurgitate food for their young. Females are very protective of their cubs, and will not tolerate other adults, particularly males, approaching them. Spotted hyenas exhibit adult behaviours very early in life; cubs have been observed to ritually sniff each other and mark their living space before the age of one month. Within ten days of birth, they are able to move at considerable speed. Cubs begin to lose the black coat and develop the spotted, lighter coloured pelage of the adults at 2–3 months. They begin to exhibit hunting behaviours at the age of eight months, and will begin fully participating in group hunts after their first year. Spotted hyenas reach sexual maturity at the age of three years. The average lifespan in zoos is 12 years, with a maximum of 25 years.