Spotted Hyena

Spotted hyaenas are still recorded in many African countries (Wilson & Reeder, 1993), although active and rapid eradication of the species in large areas, make any distribution map quickly obsolete. Fig. was obtained from the map in Skinner & Smithers (1990), and revised and updated by Dr. M. G. L. Mills (25 Mars '97).

Categorical-discrete (CD) distribution model

The species occurs in open savanna, from woodland to semi-desert scrub; it is absent in forest (Estes, 1991; Kingdon, 1971-77; Kok & Nel, 1996; Sillero-Zubiri & Gottelli, 1992b). They are adaptable to extreme environments and are found in coastal regions to mountain forests up to 4,000m. It is thought that there are 28,000-48,000 spotted hyaenas left in Africa. There are scattered populations in West and South Africa with larger populations in the rest of its former range.

Few animals have attracted such hatred and disparagement from humans as the Spotted Hyena - long regarded as a cowardly scavenger dependent upon the left-overs from the Lion - regal 'King of Beasts'. But long-term research projects in Tanzania, Botswana and elsewhere in Africa have shown this perception to be quite false, and have revealed the Spotted Hyena to be a fascinating animal and a highly sociable predator in its own right. Research has also revealed that female hyenas are dominant over males and are responsible for defending group territories. Male dominance is almost universal among mammals, but Spotted Hyena society is dominated by females, with the most senior male subordinate to the most junior female.

Spotted hyaenas weigh up to 70kg, but average between 45-55kg with the females being slightly larger than the males. Their shoulder height measures between 70 and 90 cm. Their coats are sandy or greyish brown and short with a spotted pattern. They have a very strong build with a thick neck and powerful jaws and have long front legs and short back legs causing their backs to slope. The males and females have very similar genitalia, which can make identification extremely difficult. The Spotted Hyaena has a rough coat, a reddish brown or tan colour with black spots, which gradually lightens with age.

Spotted hyaena are well known for the sounds they make, particularly at night. Spotted Hyaena have a wide variety of calls which they use to communicate with other members of their clan, as well as warning off other animals. The best known sound is the high pitched cackling "laugh", which is a sign of either excitement or fear, and is the reason for the name Laughing Hyaena. Another common sound is a loud whooping sound used to call other members of the clan.

Spotted hyaenas are usually thought of as scavengers and although they do scavenge they are also effective predators. They are opportunistic and will hunt a wide variety of prey from small mammals to the large ungulates. As they mostly hunt in groups they are capable of bringing down prey many times their own size. Because of their size and working as a team, spotted hyaenas are capable of taking kills from other carnivores including Lions. They usually hunt at night and once a kill is made they eat very quickly. With their strong teeth and powerful jaws there is very little left as they can easily crunch through the bones.

As well as using their eyes and ears for hunting they have an acute sense of smell and can detect a carcass from several kilometres away. They are also capable of chasing their prey for long distances and a chase of 24km has been recorded showing that spotted hyaenas have excellent endurance.

Spotted hyaenas are considered the most sociable of the carnivores and lives in large groups called "clans" which have a complex social structure. The clan has a strict dominance Hierarchy. The females are dominant over the males and they all defend their territory, which can range from 40km to over a 1,000 square kilometres. Even the lowest ranking female is dominant over the highest-ranking male. Young females stay in the clan and the males usual disperse at around two and a half years. Even though a clan's size maybe as large as 80 individuals they often forage alone or in small groups. The clan is normally seen together at a den site or at large kills.

The female Spotted Hyena's urinary-genital system is unique among mammals: there is no vagina, and the clitoris is modified so that it is as large, and as erectile, as the male's penis - only the shape of the glans makes it possible to tell the sexes apart. The female urinates, mates and gives birth through this modified clitoris (it is inverted for mating). It is thought that the development of this structure depends on a masculisation process triggered by the action of androgens of the developing female cub before or soon after birth. The evolutionary origins and function of this unique organ are not yet known. Birth through the clitoris is very difficult, and in addition the internal birth canal is contorted because of the unusual geometry of the external organs.

In captivity, many cubs of primiparous mothers are stillborn because of the long labour times involved; in the wild, survival rates of females seem to fall sharply around the age of first giving birth, suggesting that the process is hazardous for the mother also. This suggests that at some point there must have been powerful selective pressures driving the evolution of masculinisation.