Striped hyena
The striped hyena is a species of hyena native to North and East Africa, the Middle East, the Caucasus, Central Asia, and the Indian subcontinent. It is the only extant species in the genus Hyaena. It is listed by the IUCN as near-threatened, as the global population is estimated to be under 10,000 mature individuals which continues to experience deliberate and incidental persecution along with a decrease in its prey base such that it may come close to meeting a continuing decline of 10% over the next three generations.
It is the smallest of the bone-cracking hyenas and retains many primitive viverrid-like characteristics lost in larger species, having a smaller and less specialised skull. Though primarily a scavenger, large specimens have been known to kill their own prey, and attacks on humans have occurred in rare instances. The striped hyena is a monogamous animal, with both males and females assisting one another in raising their cubs. A nocturnal animal, the striped hyena typically only emerges in complete darkness, and is quick to return to its lair before sunrise. Although it has a habit of feigning death when attacked, it has been known to stand its ground against larger predators in disputes over food.
The striped hyena features prominently in Middle Eastern and Asian folklore. In some areas, its body parts are considered magical, and are used as charms or talismans. It is mentioned in the Hebrew Bible, where it is referred to as tzebua or zevoa, though it is absent in some Bible translations into English. Ancient Greeks knew it as γλάνος and ύαινα and were familiar with it from the Aegean coast of Asia Minor. The striped hyena is the national animal of Lebanon.
Evolution
Striped hyena fossils are common in Africa, with records going back as far as the Early Pleistocene. The species may have evolved from Hyaenictitherium namaquensis of Pliocene Africa. As fossil striped hyenas are absent from the Mediterranean region, it is likely that the species is a relatively late invader to Eurasia, having likely spread outside Africa only after the extirpation of spotted hyenas from Asia at the end of the last glacial period. The striped hyena occurred for some time in Europe during the Pleistocene, having been particularly widespread in France and Germany. It also occurred in Montmaurin, Hollabrunn in Austria, the Furninha Cave in Portugal, and the Genista Caves in Gibraltar. The European form was similar in appearance to modern populations, but was larger, being comparable in size to the brown hyena.Description
Build
The striped hyena has a fairly massive, but short torso set on long legs. The hind legs are significantly shorter than the forelimbs, thus causing the back to slope downwards. The legs are relatively thin and weak, with the forelegs being bent at the carpal region. The neck is thick, long and largely immobile, while the head is heavy and massive with a shortened facial region. The eyes are small, while the sharply pointed ears are very large, broad and set high on the head. Like all hyenas, the striped hyena has bulky pads on its paws, as well as blunt but powerful claws. The tail is short and the terminal hairs do not descend below the achilles tendon. The female striped hyena's genitalia are transiently masculinized, although it lacks the enlarged clitoris and false scrotal sack noted in the female genitalia of the spotted hyena. The female has 3 pairs of nipples. Adult weight can range from, averaging at about. Body length can range from, not counting a tail of, and shoulder height is between. The male has a large pouch of naked skin located at the anal opening. Large anal glands open into it from above the anus. Several sebaceous glands are present between the openings of the anal glands and above them. The anus can be everted up to a length of 5 cm, and is everted during social interaction and mating. When attacked, the striped hyena everts its rectum and sprays a pungent smelling liquid from its anal glands. Its sense of smell is acute, though its eyesight and sense of hearing are weak.The skull is entirely typical of the genus, having a very high sagittal crest, a shortened facial region and an inflated frontal bone. The skull of the striped hyena differs from that of the brown and spotted hyena by its smaller size and slightly less massive build. It is nonetheless still powerfully structured and well adapted to anchoring exceptionally strong jaw muscles which give it enough bite-force to splinter a camel's thigh bone. Although the dentition is overall smaller than that of the spotted hyena, the upper molar of the striped hyena is far larger. The dental formula is.
Fur
The winter coat is unusually long and uniform for an animal its size, with a luxuriant mane of tough, long hairs along the back from the occiput to the base of the tail. The coat is generally coarse and bristly, though this varies according to season. In winter, the coat is fairly dense, soft, and has well-developed underfur. The guard hairs are 50–75 mm long on the flanks, 150–225 mm long on the mane and 150 mm on the tail. In summer, the coat is much shorter and coarser, and lacks underfur, though the mane remains large.In winter, the coat is usually of a dirty-brownish grey or dirty grey colour. The hairs of the mane are light grey or white at the base, and black or dark brown at the tips. The muzzle is dark, greyish brown, brownish-grey or black, while the top of the head and cheeks are more lightly coloured. The ears are almost black. A large black spot is present on the front of the neck, and is separated from the chin by a light zone. A dark field ascends from the flanks ascending to the rear of the cheeks. The inner and outer surface of the forelegs are covered with small dark spots and transverse stripes. The flanks have four indistinct dark vertical stripes and rows of diffused spots. The outer surface of the thighs has 3–4 distinct vertical or oblique dark bands which merge into transverse stripes in the lower portion of the legs. The tip of the tail is black with white underfur.
Geographic variation
, no subspecies are recognised. The striped hyena is nonetheless a geographically varied animal. Hyenas in the Arabian peninsula have an accentuated blackish dorsal mane, with mid-dorsal hairs reaching 20 cm in length. The base colour of Arabian hyenas is grey to whitish grey, with dusky grey muzzles and buff yellow below the eyes. Hyenas in Israel have a dorsal crest which is mixed grey and black in colour, rather than being predominantly black. The largest striped hyenas come from the Middle East, Asia Minor, Central and the Indian subcontinent, while those of East Africa and the Arabian peninsula are smaller.Behaviour
Social and territorial behaviours
The striped hyena is a primarily nocturnal animal, which typically only leaves its den at the onset of total darkness, returning before sunrise. Striped hyenas typically live alone or in pairs, though groups of up to seven animals are known in Libya. They are generally not territorial, with home ranges of different groups often overlapping each other. Home ranges in the Serengeti have been recorded to be, while one in the Negev was calculated at.When marking their territory, striped hyenas use the paste of their anal pouch called hyena butter to scent mark grass, stalks, stones, tree trunks, and other objects. The composition of hyena butter differs based on the individual’s age and population of origin, and is partly determined by the fermentative bacterial composition of the hyena’s scent pouch, which include many anaerobic bacteria in the phylum Bacillota. While the composition of juvenile scent pouch bacteria is variable, adult striped hyenas have more uniform bacterial communities in their scent pouches, with specific types and amounts of each taxon present.
In aggressive encounters, the black patch near the thoracic and lumbar vertebrae is erected. When fighting, striped hyenas will bite at the throat and legs, but avoid the mane, which serves as a signaling device. When greeting each other, they lick the mid-back region, sniff each other's noses, extrude their anal pouch, or paw each other's throats. The species is not as vocal as the spotted hyena, its vocalisations being limited to a chattering laugh and howling.
Reproduction and development
The striped hyena is monogamous, with the male establishing the den with the female, helping her raise and feed when cubs are born. The mating season varies according to location; in Transcaucasia, striped hyenas breed in January–February, while those in southeast Turkmenia breed in October–November. In captivity, breeding is non-seasonal. Mating can occur at any time of the day, during which the male grips the skin of the female's neck.The gestation period lasts 90–91 days. Striped hyena cubs are born with adult markings, closed eyes, and small ears. This is in marked contrast to newborn spotted hyena cubs which are born almost fully developed, though with black, unmarked coats. Their eyes open after 7–8 days, and the cubs leave their dens after one month. Cubs are weaned at the age of 2 months, and are then fed by both parents. By autumn, the cubs are half the size of their parents. In the wild, striped hyenas can live for 12 years, while in captivity they have been known to reach 23.