Striped hyena

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Striped hyena
Striped Hyena 5.jpg

Striped hyena ( Hyaena hyaena )

Systematics
Order : Predators (Carnivora)
Subordination : Feline (Feliformia)
Family : Hyenas (Hyaenidae)
Subfamily : Actual hyenas (Hyaeninae)
Genre : Hyaena
Type : Striped hyena
Scientific name of the  genus
Hyaena
Brisson , 1762
Scientific name of the  species
Hyaena hyaena
( Linnaeus , 1758)

The striped hyena ( Hyaena hyaena ) is a species of predator from the hyena family (Hyaenidae). It can be recognized by its striped fur and is the only member of its family that is not only found in Africa , but also in western and southern Asia . It is nocturnal and can live both solitary and in small groups. Its food consists mainly of the carrion of larger animals, but it also eats small animals that it has killed itself and plant material. Due to hunting and other factors, the numbers are declining.

features

General build and coat

The striped hyena is the smallest of the three real hyenas , but significantly larger than the fourth hyena species, the aardwolf , with which it shares external features such as the striped fur. It reaches a head body length of 100 to 115 centimeters, to which a 30 to 40 centimeter long tail comes. The shoulder height is 66 to 75 centimeters, the weight varies between 26 and 41 kilograms. There is no significant sexual dimorphism in terms of size, meaning that males and females are approximately the same size. However, the animals in the north of the distribution area are slightly larger than animals in the south.

The fur is relatively long and looks shaggy. The tail is bushy. A gray or yellowish-gray mane extends from the ears along the back to the tail. The mane can be straightened up, making the animal appear significantly larger. With hair up to eight inches long on their shoulders, striped hyenas have the longest mane of all hyenas. The basic color of the fur is light gray to yellowish gray, on the flanks there are five to nine black stripes that are sometimes only indistinctly visible. There are several more clearly visible horizontal stripes on the legs. The muzzle is black, as is the throat patch and two stripes on the cheeks.

Like all hyenas, striped hyenas are digitigrad (toe walkers). The front legs are longer than the rear legs, which causes the falling back typical of this group of animals. The front and rear paws each end in four toes, which are provided with blunt, non-retractable claws .

Striped hyenas have a well-developed anal gland whose secretion is used to mark territory. The females have two or three pairs of teats - if there are three pairs, only the back two pairs are functional. As with all hyenas, the males lack penis bones . Similar to the spotted hyena , striped hyenas show peculiarities in the structure of the genital tract , but only in growing animals. Young females have bulging labia in front of the vagina , these bulges are hairless, dark and rough. The young males have soft, hairless folds of skin in front of the scrotum . In contrast to the spotted hyena, these forms are not so pronounced that the gender can no longer be determined. These bulges are only visible in the first two years of life; adult animals show an inconspicuous structure of the genitals.

Head and teeth

The structure of the skull and the teeth of the striped hyena resembles that of the other real hyenas. The neck and shoulders are massive and strong. The head is rounded, the hairless muzzle is broad. The eyes show a tapetum lucidum as an adaptation to the nocturnal way of life , the ears are long and pointed. The jaws are strong, the strong jaw muscles, especially the temporalis muscle , have a high sagittal ridge on the skull as a point of attachment.

The tooth formula is I 3/3 - C 1/1 - P 4/3 M 1/1, so you have a total of 34 teeth. The incisors are inconspicuous, as are the canines . The premolars, which are adapted to the breaking of bones, are, however, enlarged and strongly built. They have a complex structure of the tooth enamel , which prevents the teeth from breaking. The upper third and lower third premolars are primarily used to break bones. As in all land carnivores , the fourth upper premolar and the lower molar are developed into fangs ; these teeth are blade-shaped and are used to cut meat.

distribution and habitat

Approximate distribution map of the striped hyena - its distribution area is fragmentary, in some places it is probably extinct

Striped hyenas have the northernmost range of all hyenas and at the same time the only one that is not limited to Africa , but also includes parts of Asia .

In Africa, their distribution area extends from the north of the continent to the Sahel , in the east it extends along the Nile valley to Tanzania . In Asia they are distributed from Turkey and the Caucasus region across parts of the Arabian Peninsula and Central Asia to central India .

Their current distribution is fragmented and fragmented, and isolated populations are numerous. There are no recent reports of striped hyenas from a number of countries including Sudan , Eritrea , Somalia , Qatar , Kuwait , United Arab Emirates , Pakistan and Afghanistan , and they may have become extinct in at least some of these countries.

Striped hyenas prefer open, dry habitats as a habitat. They are often found in rocky mountain regions, semi-deserts or bush-lined savannas. They avoid pure deserts, but colonize, for example, the mountainous regions in the interior of the Sahara . In Pakistan they have been sighted at 3300 meters above sea level, in the Atlas Mountains and in the Ethiopian highlands at altitudes over 2300 meters. They avoid areas where the temperature can drop below –15 to –20 ° C and where there is frost for more than 80 to 120 days a year. They are not afraid of people and can be found in some places near settlements, such as Tel Aviv Airport or in the suburbs of Algiers .

Striped hyenas are rare in their entire range and occur in low population densities. Estimates from Africa put two to three adult animals per 100 square kilometers.

Way of life

The striped hyena is the least explored of the four living hyena species. Many aspects are known only through a few observations, some of which also contradict each other.

Activity times and social behavior

Striped hyena with erect mane

Striped hyenas are mainly nocturnal, only when it is raining or cloudy do they sometimes go for food in the late afternoon or early morning. Their level of activity may also depend on external factors, so they could be more strictly nocturnal in more densely populated areas than in sparsely populated regions. Caves in the ground, crevices in the rock or dug structures serve as resting places. Buildings from the Karakum Desert had a narrow entrance 0.7 meters in diameter and stretched 4 to 5 meters, while a structure examined in Israel was 27 meters long.

There are different observations about social behavior; it is presumably variable. Most reports speak of solitary animals. In some areas, such as Central Asia , however, a male and a female often join forces and form family groups together with the offspring from several litters. These pair bonds are relatively stable and can be sustained for several years. Reports from Kenya say that the animals live mainly solitary, but show a polyandric territorial behavior. This means that the territory of a female overlaps with that of up to three males. The degree of overlap of the territories of animals living together in this way is up to 85%. Sometimes the animals can also be seen resting together during the day, but they undertake the nightly forays alone. In general, female striped hyenas are extremely intolerant of other females, both in the wild and in captivity.

Various studies have shown an area size of 44 to 82 km², with no significant differences between the sexes. The territorial behavior is not very pronounced, the territories can overlap with those of other striped hyenas. There are also observations of animals that often mark their territory with the secretion of their anal glands. The glandular secretion is yellowish to beige in color and is attached to tufts of grass, stones and tree stumps. The stamps are spread all over the territory and not just on the borders, they also sometimes mark cadavers and food bowls in captivity. In addition, they dig pits next to frequently traveled routes, in which they defecate regularly.

During aggressive encounters with fellow hyenas, striped hyenas straighten their back mane, making them appear larger. In addition, they can lift their tails and bristle like a bottle brush. If it comes to a fight, the opponents try to bite each other in the throat or legs. The defeated animal arches its body, lowers its mane and swings its head back and forth, while the winner remains upright with his mane raised. If two animals from the same group meet after they have separated, they, like all real hyenas, show a typical greeting behavior. They sniff each other's nose and anal gland and lick his back. The tail is erected at these greetings.

Striped hyenas are relatively quiet animals that make little noise . Well-known sounds are howling that young animals utter, a screeching that can be heard when they are frightened or hunted by conspecifics, a drawn-out roar that goes along with the defensive stance, and a growl that is heard during a fight. The striped hyena does not make sounds resounding or laughing from afar, as they are known from the spotted hyena .

food

Two striped hyenas eat the carcass of a horse - drawing by Walter Heubach

Striped hyenas are scavengers who also eat prey and plant material that they have killed themselves. A large part of their food is made up of the carrion of larger vertebrates that have been torn by spotted hyenas, cheetahs , leopards , lions or tigers . Thanks to their strong teeth, they can break thick bones or turtle shells, and their efficient digestive system utilizes all parts of an animal's body with the exception of hair, hooves and horns. The bacterial toxins contained in the carrion do not affect your digestive or immune systems. In addition to the carrion of larger animals, they eat small mammals , birds , reptiles , insects and other small animals. They probably kill them themselves in most cases. What is the relationship between carrion and self-killed prey in their diet and whether they are able to kill even larger prey is controversial. According to some researchers, the larger striped hyenas in the north of the distribution area could well hunt large animals such as sheep , goats and horses , but the smaller ones in the south cannot. In addition, herbal material complements her menu. In Africa they eat the fruits of the desert dates , in Central Asia those of the olive pastures . In Israel , they sometimes invade plantations and eat dates and melons .

In the vicinity of human settlements, garbage cans offer a welcome supply of food. There are reports from several regions that striped hyenas, at least in the past, often dug up graves in order to retrieve and eat the corpses . Attacks on people, especially children, also sometimes occur.

Striped hyenas always go solitary in search of food, although several animals can gather together in a large carcass. When foraging for food, they cover 7 to 27 kilometers per night and move either on clear trails or in a zigzag course across the terrain. They are able to memorize the location of a fruit-bearing tree or trash can and return there on other routes as well. Sometimes they drag food remains into their burrows, presumably to keep them safe from other scavengers.

They are able to drink salty water, but often get their fluid needs from fruits.

Reproduction

As far as is known, mating can take place all year round, there are no signs of seasonality. There are no observations about courtship behavior in the wild. The reproductive behavior is either promiscuous , meaning that males and females mate with several partners, or polyandric , meaning that a female reproduces with several males. The females mate not only with the males with whom their territory overlaps, but also with others. Around half of all litters are produced by more than one male.

After a gestation period of around 90 to 92 days, the female gives birth to one to four young animals, and up to five in captivity. The newborns weigh around 700 grams, their fur is similar to that of the adult with the exception of the missing mane, instead they have a dark eel line . Their eyes and ears are closed and they can hardly crawl, so they are less developed than, for example, newborn spotted hyenas.

They spend their first weeks of life in their mother's den, after five to nine days their eyes open and after around two weeks they come outside for the first time. At around 30 days, the siblings of a litter begin to play with each other. At about the same time they eat meat for the first time. Mainly the females take care of the offspring, but sometimes the males or in family groups the older siblings also provide the young animals with food. It takes more than a year for the young to be finally weaned, and sexual maturity also occurs in the second year of life. The highest known age in human care was 24 years.

Striped hyenas and humans

Striped hyena in Tierpark Berlin

In large parts of their range, striped hyenas have a bad reputation and are considered cowardly or stupid animals. There are some superstitious beliefs associated with them: in India it is claimed that the tongue of animals reduces the risk of tumors and that their fat is good for rheumatism , in North Africa their hair is used as a talisman and the brain is considered an aphrodisiac . In ancient Egypt the animals were tamed and used for hunting purposes. In addition, they were also fattened and eaten there; there are pictorial representations of them, including on the mastaba of Mereruka . This practice was also practiced by the Tuareg at least until the 1940s . At least until the 1970s, fights between domestic dogs and striped hyenas were staged in Afghanistan and the hyena's body parts were then used for magical purposes.

Because they sometimes kill grazing animals and because of the at least alleged desecration of graves and attacks on people, they are still hunted. The hunt is often carried out with poison bait, with which striped hyenas are very easy to kill. Sometimes their poisoning is also unintentional, for example they were exterminated on the Mediterranean coast of Palestine by the British mandate in the interwar period . The target of this campaign was actually the golden jackal, feared as a carrier of rabies . In addition, there is the reduced food supply due to the decline in the number of predators, so that there is less carrion for the hyenas. Automobile traffic represents a further hazard. This risk is increased by the fact that hyenas often eat the carcasses of animals run over directly on the street and are careless towards vehicles following behind.

The striped hyena population is declining. Their range is now fragmented and divided into many small, isolated populations. A conservative estimate puts the total global population at 5,000 to 14,000 animals. The IUCN lists the species as " near threatened " due to the low population and continued hunting .

Systematics

The striped hyena is one of the four living species of hyenas (Hyaenidae). Its closest relative and therefore its sister taxon is the black horned hyena that lives in southern Africa . This is either classified in the same genus ( Hyaena ) or is considered a representative of its own, closely related genus Parahyaena . Differences between the species lie, among other things, in the structure of the premolars and other details of the skull structure - for example, in the striped hyena the first upper premolar is larger, the palate extends less far back, and the atlas and axis overlap less. The two species were separated around 4.2 million years ago.

Fossil , the genus Hyaena has been passed down since the late Pliocene , and in the Pleistocene its range stretched from the British Isles and the Iberian Peninsula to China .

On the basis of the large distribution area, five subspecies are distinguished: the nominate form Hyaena hyaena hyaena from India, H. h. barbara from North West Africa, H. h. syriaca from Asia Minor and the Caucasus Region, H. h. dubbah from eastern Africa and H. h. sultana from the Arabian Peninsula. The two last-mentioned subspecies dubbah and sultana are considered to be small, southern subspecies, which contrast with the northern, somewhat larger subspecies. Overall, however, the differences are only weak, so that this classification can be questioned on the basis of the data currently available.

literature

  • Kay E. Holekamp, ​​Joseph M. Kolowski: Family Hyaenidae (Hyenas) . In: Don E. Wilson, Russell A. Mittermeier (eds.): Handbook of the Mammals of the World. Volume 1: Carnivores . Lynx Edicions, 2009, ISBN 978-84-96553-49-1 , pp. 234-261 .
  • Ingo Rieger: Hyaena hyaena . In: Mammalian Species 150 . 1981, p. 1-5 . ( Online as PDF [accessed January 22, 2010]).
  • Ronald M. Nowak: Walker's Mammals of the World . Johns Hopkins University Press, 1999, ISBN 0-8018-5789-9 .

Individual evidence

  1. Figures from Holekamp & Kolowski (2009), p. 256.
  2. a b c d Hyaena hyaena in the IUCN Red List of Threatened Species . Retrieved September 3, 2009.
  3. a b c d Holekamp & Kolowski (2009), p. 257.
  4. a b c Rieger (1981), p. 3.
  5. ^ Tomb of Mereruka on Egyptian Monuments , accessed September 4, 2009
  6. ^ H. Lhote: Observation sur la répartition actuelle et les moeurs de quelques grands mammifères du pays Touareg. In: Mammalia 10, 1 (1946), pp. 26-56 .; quoted after Rieger (1981), p. 3.
  7. ^ Jürgen W. Frembgen: The Magicality of the Hyena. Beliefs and Practices in West and South Asia. In: Asian Folklore Studies 57 (1998), pp. 331-344. PDF ( Memento of the original from June 25, 2008 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2Template: Webachiv / IABot / www.nanzan-u.ac.jp
  8. Holekamp & Kolowski (2009), p. 251.
  9. for example at WC Wozencraft: Order Carnivora. In: DE Wilson and DM Reeder: (Ed.) Mammal Species of the World : a taxonomic and geographic reference. , Washington, Smithsonian Institution Press 1993, pp. 279-344.
  10. e.g. in Nowak (1999) or Holekamp & Kolowski (2009).
  11. Nowak (1999), p. 788.
  12. Klaus-Peter Koepfli, Susan M. Jenks, Eduardo Eizirik, Tannaz Zahirpour, Blaire Van Valkenburgh and Robert K. Wayne: Molecular systematics of the Hyaenidae: Relationships of a relictual lineage resolved by a molecular supermatrix. In: Molecular Phylogenetics and Evolution 38 (2006) 603-620.
  13. Rieger (1981), p. 2.

Web links

Commons : Striped Hyena  - Collection of images, videos and audio files
This version was added to the list of articles worth reading on February 9, 2010 .