Post by Theropod on May 1, 2014 23:32:40 GMT
Striped Hyena - Hyaena hyaena
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Clade: Holotheria
Superlegion: Trechnotheria
Legion: Cladotheria
Sublegion: Zatheria
Infralegion: Tribosphenida
Subclass: Theria
Infraclass: Eutheria
Magnorder: Boreoeutheria
Superorder: Laurasiatheria
(unranked): Zooamata
(unranked): Ferae
(unranked): Carnivoramorpha
Order: Carnivora
Suborder: Feliformia
Family: Hyaenidae
Genus: Hyaena
Species: Hyaena hyaena
Striped Hyena range
The striped Hyena (Hyaena hyaena) is a species of true hyena native to North and East Africa, the Middle East, the Caucasus, Central Asia and the Indian Subcontinent. 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 true hyenas and retains many primitive viverrid 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 on 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. Though it has a habit of feigning death when attacked, it has also been known to stand its ground against larger predators such as Leopards in disputes over food.
Evolution
The species may have evolved from H. namaquensis of Pliocene Africa. Striped Hyena fossils are common in Africa, with records going back as far as the Middle Pleistocene and even to the Villafranchian. 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 extinction of spotted hyenas in Asia at the end of the Ice Age. 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.
Physical description
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 calcaneal tendon. Adult weight can range from 22 to 55 kg (49 to 121 lb), averaging at about 35 kg (77 lb). Body length can range from 85 to 130 cm (33 to 51 in), not counting a tail of 25 to 40 cm (9.8 to 15.7 in), and shoulder height is between 60–80 cm (24–31 in). Its eyesight is acute, though its senses of smell and 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 muscleswhich 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:
Dentition, as illustrated in Knight's Sketches in Natural History
V. N. Lyakhov's depiction of the dorsal, ventral and lateral views of the Striped Hyena's skull.
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 gray 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
As of 2005, 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 Asia and the Indian subcontinent, while those of east Africa and the Arabian peninsula are smaller.
Behavior
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 in groups of 1–2 animals, though groups of up to seven animals are known in Libya. They are generally not territorial animals, with home ranges of different groups often overlapping each other. Home ranges in the Serengheti have been recorded to be 44 km² (17 sq mi)-72 km² (28 sq mi), while one in the Negev desert was calculated at 61 km² (24 sq mi). 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 signalling device. The species is not as vocal as the spotted hyena, its vocalisations being limited to a chattering laugh and howling.
A pair of striped hyenas fighting at the Colchester Zoo
Burrowing behaviours
The striped hyena may dig its own dens, but it also establishes its lairs in caves, rock fissures, erosion channels and burrows formerly occupied by porcupines, wolves, warthogs and aardvarks. Hyena dens can be identified by the presence of bones at their entrances. The striped hyena hides in caves, niches, pits, dense thickets, reeds and plume grass during the day to shelter from predators, heat or winter cold. The size and elaboration of striped hyena dens varies according to location; dens in the Karakum have entrances 0.67–0.72 m wide and are extended over a distance of 4.15–5 m, with no lateral extensions or special chambers. In contrast, hyena dens in Israel are much more elaborate and large, exceeding 27 m in length.
Diet
The striped hyena is primarily a scavenger which feeds mainly on ungulate carcasses in different stages of decomposition, fresh bones, cartilages, ligaments and bone marrow. It crushes long bones into fine particles and swallows them, though sometimes entire bones are eaten whole. The striped hyena is not a fussy eater, though it has an aversion to vulture flesh. It will occasionally attack and kill any animal it can overcome. It hunts prey by running it down, grabbing its flanks or groin and inflicting mortal wounds by tearing out the viscera. In Turkmenistan, the species is recorded to feed on wild boar, kulan, porcupines and tortoises. A seasonal abundance of oil willow fruits is an important food source in Uzbekistan and Tajikistan, while in the Caucasuses, it is grasshoppers. In Israel, the striped hyena feeds on garbage, carrion and fruits. In eastern Jordan, its main sources of food are feral horse and water buffalo carcasses and village refuse. It has been suggested that only the large hyenas of the Middle East, Asia minor, central Asia and the Indian subcontinent attack large prey, with no evidence of their smaller Arabian and east African cousins doing so. Because of its scavenging diet, the striped hyena requires more water to survive than most other carnivores. When eating, the striped hyena gorges itself until satisfied, though hyenas with cubs will transport food to their dens.
Female striped hyena feeding on chital
Striped hyaena scavenging shark carcass
Relationships with other predators
The striped hyena competes with the gray wolf in the Middle East and central Asia. In the latter area, a great portion of the hyena's diet stems from wolf-killed carcasses. The striped hyena is dominant over the wolf on a one to one basis, though wolves in packs can displace single hyenas from carcasses. Both species have been known to share dens on occasion. Red foxes may compete with striped hyenas on large carcasses. Red foxes may give way to hyenas on unopened carcasses, as the latter's stronger jaws can easily tear open flesh which is too tough for foxes. Foxes may harass hyenas, using their smaller size and greater speed to avoid the hyena's attacks. Sometimes, foxes seem to deliberately torment hyenas even when there is no food at stake. Some foxes may mistime their attacks, and are killed. The species frequently scavenges from the kills of felids such as tigers, leopards, cheetahs and caracals. A caracal can drive a subadult hyena from a carcass. The hyena usually wins in one-to-one disputes over carcasses with leopards, cheetahs and tiger cubs, but is dominated by adult tigers.
Range and population
The striped hyena's historical range encompasses Africa north of and including the Sahel zone, eastern Africa south into Tanzania, the Arabian Peninsula and the Middle East up to the Mediterranean shores, Turkey, Iraq, the Caucasus (Azerbaijan, Armenia, Georgia), Iran, Turkmenistan, Uzbekistan, Tajikistan, Afghanistan (excluding the higher areas of Hindukush) and the Indian Subcontinent. Today the species' distribution is patchy in most ranges, thus indicating that it occurs in many isolated populations, particularly in most of west Africa, most of the Sahara, parts of the Middle East, the Caucasus and central Asia. It does however have a continuous distribution over large areas of Ethiopia, Kenya, and Tanzania. Its modern distribution in Pakistan, Iran and Afghanistan is unknown with some sizable large number in India in open areas of Deccan Peninsula.
A wild individual at Blackbuck National Park, Velavadar
Tameability
The striped hyena is easily tamed and can be fully trained, particularly when young. Although the Ancient Egyptians did not consider striped hyenas sacred, they supposedly tamed them for use in hunting. When raised with a firm hand, they may eventually become affectionate and as amenable as well trained dogs, though they emit a strong odour which no amount of bathing will cover. Although they kill dogs in the wild, striped hyenas raised in captivity can form bonds with them.
Links
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Clade: Holotheria
Superlegion: Trechnotheria
Legion: Cladotheria
Sublegion: Zatheria
Infralegion: Tribosphenida
Subclass: Theria
Infraclass: Eutheria
Magnorder: Boreoeutheria
Superorder: Laurasiatheria
(unranked): Zooamata
(unranked): Ferae
(unranked): Carnivoramorpha
Order: Carnivora
Suborder: Feliformia
Family: Hyaenidae
Genus: Hyaena
Species: Hyaena hyaena
Striped Hyena range
The striped Hyena (Hyaena hyaena) is a species of true hyena native to North and East Africa, the Middle East, the Caucasus, Central Asia and the Indian Subcontinent. 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 true hyenas and retains many primitive viverrid 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 on 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. Though it has a habit of feigning death when attacked, it has also been known to stand its ground against larger predators such as Leopards in disputes over food.
Evolution
The species may have evolved from H. namaquensis of Pliocene Africa. Striped Hyena fossils are common in Africa, with records going back as far as the Middle Pleistocene and even to the Villafranchian. 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 extinction of spotted hyenas in Asia at the end of the Ice Age. 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.
Physical description
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 calcaneal tendon. Adult weight can range from 22 to 55 kg (49 to 121 lb), averaging at about 35 kg (77 lb). Body length can range from 85 to 130 cm (33 to 51 in), not counting a tail of 25 to 40 cm (9.8 to 15.7 in), and shoulder height is between 60–80 cm (24–31 in). Its eyesight is acute, though its senses of smell and 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 muscleswhich 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:
Dentition |
3.1.4.0-1 |
3.1.3.1 |
Dentition, as illustrated in Knight's Sketches in Natural History
V. N. Lyakhov's depiction of the dorsal, ventral and lateral views of the Striped Hyena's skull.
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 gray 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
As of 2005, 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 Asia and the Indian subcontinent, while those of east Africa and the Arabian peninsula are smaller.
Behavior
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 in groups of 1–2 animals, though groups of up to seven animals are known in Libya. They are generally not territorial animals, with home ranges of different groups often overlapping each other. Home ranges in the Serengheti have been recorded to be 44 km² (17 sq mi)-72 km² (28 sq mi), while one in the Negev desert was calculated at 61 km² (24 sq mi). 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 signalling device. The species is not as vocal as the spotted hyena, its vocalisations being limited to a chattering laugh and howling.
A pair of striped hyenas fighting at the Colchester Zoo
Burrowing behaviours
The striped hyena may dig its own dens, but it also establishes its lairs in caves, rock fissures, erosion channels and burrows formerly occupied by porcupines, wolves, warthogs and aardvarks. Hyena dens can be identified by the presence of bones at their entrances. The striped hyena hides in caves, niches, pits, dense thickets, reeds and plume grass during the day to shelter from predators, heat or winter cold. The size and elaboration of striped hyena dens varies according to location; dens in the Karakum have entrances 0.67–0.72 m wide and are extended over a distance of 4.15–5 m, with no lateral extensions or special chambers. In contrast, hyena dens in Israel are much more elaborate and large, exceeding 27 m in length.
Diet
The striped hyena is primarily a scavenger which feeds mainly on ungulate carcasses in different stages of decomposition, fresh bones, cartilages, ligaments and bone marrow. It crushes long bones into fine particles and swallows them, though sometimes entire bones are eaten whole. The striped hyena is not a fussy eater, though it has an aversion to vulture flesh. It will occasionally attack and kill any animal it can overcome. It hunts prey by running it down, grabbing its flanks or groin and inflicting mortal wounds by tearing out the viscera. In Turkmenistan, the species is recorded to feed on wild boar, kulan, porcupines and tortoises. A seasonal abundance of oil willow fruits is an important food source in Uzbekistan and Tajikistan, while in the Caucasuses, it is grasshoppers. In Israel, the striped hyena feeds on garbage, carrion and fruits. In eastern Jordan, its main sources of food are feral horse and water buffalo carcasses and village refuse. It has been suggested that only the large hyenas of the Middle East, Asia minor, central Asia and the Indian subcontinent attack large prey, with no evidence of their smaller Arabian and east African cousins doing so. Because of its scavenging diet, the striped hyena requires more water to survive than most other carnivores. When eating, the striped hyena gorges itself until satisfied, though hyenas with cubs will transport food to their dens.
Female striped hyena feeding on chital
Striped hyaena scavenging shark carcass
Relationships with other predators
The striped hyena competes with the gray wolf in the Middle East and central Asia. In the latter area, a great portion of the hyena's diet stems from wolf-killed carcasses. The striped hyena is dominant over the wolf on a one to one basis, though wolves in packs can displace single hyenas from carcasses. Both species have been known to share dens on occasion. Red foxes may compete with striped hyenas on large carcasses. Red foxes may give way to hyenas on unopened carcasses, as the latter's stronger jaws can easily tear open flesh which is too tough for foxes. Foxes may harass hyenas, using their smaller size and greater speed to avoid the hyena's attacks. Sometimes, foxes seem to deliberately torment hyenas even when there is no food at stake. Some foxes may mistime their attacks, and are killed. The species frequently scavenges from the kills of felids such as tigers, leopards, cheetahs and caracals. A caracal can drive a subadult hyena from a carcass. The hyena usually wins in one-to-one disputes over carcasses with leopards, cheetahs and tiger cubs, but is dominated by adult tigers.
Range and population
The striped hyena's historical range encompasses Africa north of and including the Sahel zone, eastern Africa south into Tanzania, the Arabian Peninsula and the Middle East up to the Mediterranean shores, Turkey, Iraq, the Caucasus (Azerbaijan, Armenia, Georgia), Iran, Turkmenistan, Uzbekistan, Tajikistan, Afghanistan (excluding the higher areas of Hindukush) and the Indian Subcontinent. Today the species' distribution is patchy in most ranges, thus indicating that it occurs in many isolated populations, particularly in most of west Africa, most of the Sahara, parts of the Middle East, the Caucasus and central Asia. It does however have a continuous distribution over large areas of Ethiopia, Kenya, and Tanzania. Its modern distribution in Pakistan, Iran and Afghanistan is unknown with some sizable large number in India in open areas of Deccan Peninsula.
A wild individual at Blackbuck National Park, Velavadar
Tameability
The striped hyena is easily tamed and can be fully trained, particularly when young. Although the Ancient Egyptians did not consider striped hyenas sacred, they supposedly tamed them for use in hunting. When raised with a firm hand, they may eventually become affectionate and as amenable as well trained dogs, though they emit a strong odour which no amount of bathing will cover. Although they kill dogs in the wild, striped hyenas raised in captivity can form bonds with them.
Links