Cap hyena
| Cap hyena | ||||||||||||
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Saddleback hyena ( Parahyaena brunnea ) |
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| Systematics | ||||||||||||
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| Scientific name of the genus | ||||||||||||
| Parahyaena | ||||||||||||
| Hendey , 1974 | ||||||||||||
| Scientific name of the species | ||||||||||||
| Parahyaena brunnea | ||||||||||||
| ( Thunberg , 1820) |
The black hyena ( Parahyaena brunnea or Hyaena brunnea ), also known as the brown hyena or beach wolf , is a species of predator from the hyena family (Hyaenidae). It weighs around 40 kilograms and is the only type of hyena whose fur is barely patterned or striped. It lives in arid areas in southern Africa . It is predominantly nocturnal and has a complex social behavior: It lives in groups called “clans”, but whose members go for food alone. Its food consists mainly of the carrion of larger animals, but it also hunts smaller animals itself.
features
Build and coat
The blue hyena is the middle size of the three real hyenas (Hyaeninae), it is larger than the striped hyena , but smaller than the spotted hyena . The head-trunk length is 110 to 136 centimeters, plus a 19 to 27 centimeter long tail. The shoulder height is around 70 centimeters in males and around 74 centimeters in females. The weight varies between 28 and 47.5 kilograms and averages 40 kilograms. There is moderate sexual dimorphism : the males are slightly longer and heavier than the females, but lower. As with all hyenas, the front legs are longer and stronger than the rear legs, causing the back to slouch backwards. The front and rear paws each end in four toes with blunt, non-retractable claws . Like all hyenas, they are digitigrad (toe walkers).
The long fur looks shaggy and the tail is bushy. The animals owe their German name to this long fur. From the shoulders on, longer hair runs down the back to the tail; they form a mane that can be straightened up. The black hyena is the only type of hyena that is not patterned or striped, its fur is predominantly a single color, dark brown. Only the neck and shoulders are contrasting yellowish beige, and along the legs there are some dark and light horizontal stripes.
Saddleback hyenas have a well-developed anal pouch , the secretion of which is used to mark territory. The females have two to six pairs of teats, but only the back two pairs are functional. As with all hyenas, the males lack penis bones . In contrast to striped or spotted hyenas, black hyenas show no abnormalities in the structure of the genital tract .
Head and teeth
The construction of the skull and the teeth of the common 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 have 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 crest on the skull as their point of origin .
The tooth formula is I 3/3 - C 1/1 - P 4/3 M 1/1, a total of 34 teeth. The incisors are inconspicuous, the canines are somewhat elongated. The premolars, which are adapted to the breaking of bones, are greatly 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 and form a scissor bite ; these teeth are blade-shaped and are used to cut meat.
distribution and habitat
Saddleback hyenas live exclusively in southern Africa and thus have the smallest distribution area of all hyena species. It extends from southern Angola and southern Zimbabwe across large parts of Namibia and Botswana to South Africa . The main focus of the population distribution is presumably in the central and southern Kalahari as well as along the coast of Namibia. Since the 18th century their range has shrunk significantly, so they became extinct in the south of the former Cape Province . However, sightings of individual animals could be an indication that they are slowly repopulating this region - unless they are individual, migrating animals.
They inhabit a number of dry habitats and occur, for example, in deserts and semi-deserts, but also in bushland and savannas. They prefer areas with less than 100 millimeters to 650 millimeters of annual precipitation . They are relatively rare, the population densities are 1 to 3 animals per 100 km².
Way of life
Activity times and social behavior
Saddleback hyenas are predominantly nocturnal animals, only in cool, cloudy weather they sometimes go looking for food during the day. There are two activity times: from 7:30 p.m. to midnight and from 2:30 a.m. to 6:00 a.m., with a short rest in between. Animals equipped with radio collars were active on average 42.6% from 24 hours and 80.2% from 6:00 p.m. to 6:00 a.m. During the day they sleep in a hole in the ground or under a bush.
The animals live in stable groups called " clans ". However, only around two thirds of the individuals in an area form clans, the rest of them live as solitary nomads. A clan consists of 4 to 14 animals, the composition can vary regionally. Since the females often remain in their birth group, but the males have to leave them, a group of related females often forms the core of a clan. One to five adult females live in each clan; if there are more, the surplus females are chased out of the group by the others. In some cases, a hierarchy is formed that includes preferential access to food resources. This ranking is established both within the males and within the females, the highest-ranking male and the highest-ranking female have equal rights. Whether a hierarchy is formed depends on the population density and reproductive behavior. If the population density is low, i.e. if there is a better food supply, this is not necessary, nor if the young are regularly conceived by males from outside the clan.
Clans inhabit large, permanent territories . The size of the area correlates with the food supply and also varies depending on the season. In the southern Kalahari the average area size is 308 km², in the central Kalahari it is significantly smaller at 170 km². On the coast of Namibia with the rich supply of seals, the size can be only 32 km², while inland it can increase to over 1000 km². The districts do not overlap by more than 20%.
Since spotted hyenas move largely alone, the most important form of communication is olfactory communication , i.e. by means of smells. The territories are marked with glandular secretions, the animals brush their anal sac over a tuft of grass or a similar object, whereby an intensely smelling white liquid and a weaker black liquid are secreted. Although Mark all hyena species their territories with Analbeutelsekret, but the two different secretions occur only in brown hyena ago. Even humans can still smell the white liquid after 30 days, while the black liquid is no longer noticeable after a few hours. Presumably the black liquid is used to give clues about the time of segregation and thus to inform other clan members of their own presence. This can prevent several animals from searching the same area for food. The long-lasting white liquid makes non-clan animals aware of the clan's territory. In addition to the glandular secretions, they also create pits of excrement, which also give the conspecifics information about their own presence. Dung pits are often located at prominent landscape points.
If two animals from the same clan meet after they have separated, they, like all real hyenas, show a typical greeting behavior. They crouch down and present their anal pouch to the other, who sniffs them. They put their ears back and pull their lips back so that the teeth become visible. These greetings can last up to five minutes. When threatened, the animals straighten their manes, making them appear larger. Fights with conspecifics are often carried out through ritualized neck bites. These battles can take place both between non-clan animals and between members of the same clan to consolidate the hierarchy. The superior animal grabs the neck of the other with its incisors and canine teeth and shakes it wildly back and forth.
Saddleback hyenas are quiet animals that make little noise . Screeching sounds that express submission and a threatening growl that accompanies aggressive postures are known. These hyenas do not allow these hyenas to resound from far away or laughing sounds, as they are known from the spotted hyena.
food
Saddleback hyenas are predominantly scavengers , but they also feed on animals and plant material that they have killed themselves. The main part of their diet is the carrion of larger animals. Thanks to their strong teeth, they can break even thick bones, 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. For example, they eat young springboks , spring hares , spoonhounds and ground-breeding birds on animals they hunted . They are not skilled hunters, their hunting style is unspecialized, most hunts fail. Insects , ostrich eggs and other things complement their diet. Unlike the larger spotted hyenas, they can break these eggs open with their jaws. The hyenas of the Namibian coastal region have developed their own form of nutrition: They mainly eat the cubs of the South African fur seals , which, in contrast to the other animals, they hunt themselves with considerable success.
They live in sometimes very dry regions - in the Kalahari there is no water available eight months a year - and do not need to drink. However, when water is available, they drink daily. Otherwise, they cover their fluid requirements with various cucurbits such as tsama melons , gemsbok cucumbers or Hookeri melons.
They go in search of food one by one and cover great distances. In Namibia the nocturnal forays measure 15 to 47 kilometers, in the Kalahari it can be up to 54 kilometers. They move on zigzag routes and rely primarily on their sense of smell to track down food. With larger carcasses, several animals can gather and eat peacefully next to each other.
Usually they eat the carrion on the spot, but parts of larger carcasses are sometimes hidden in tall grass or under bushes. These hiding spots are marked with glandular secretions and will be visited again and again over the next few days. There was one observation in which a black hyena found an empty ostrich nest with 26 eggs. She moved 14 eggs away over the next four hours and stored them 150 to 600 meters from the nest. During this time she only ate three eggs.
Reproduction
The mating behavior of the black hyenas is variable. Sometimes the females only mate with nomadic males who roam solitary in the area of the clan without their own territory. In other cases, the males who immigrated to the clan take on this role. The bond between the immigrant males remains loose and rarely lasts longer than three years. The reasons for this change are not exactly known. Possibly it is related to the food supply: Mating with nomadic males takes place mainly in the dry season, when the food supply is low and the roaming areas expand, it can be difficult to maintain contact with other clan members.
Mating can take place all year round. After a gestation period of around 96 days , the female usually gives birth to two or three young, the number can vary from one to five. Newborns are born with their eyes closed, and their fur is similar to that of adult animals. They spend their first few weeks in an earthworks. In some regions, each female has her own burrow , in the central Kalahari, however, there are community burrows in which the young of different females and different ages reside. Sometimes the females also suckle other young animals, but they always prefer their own. At eight days their eyes begin to open, in the first three months of life they leave the building, at best accompanied by an adult. From the fourth month of life, both the mother and other clan members begin to bring food to the young animals. The lining is carried and not strangled up again. At around ten months, the growing animals begin to go for longer forays outside the burrow, at the latest after 15 months they leave the maternal burrow forever. As with all real hyenas, the breastfeeding period lasts relatively long, and the young are finally weaned at 12 to 16 months. From the age of 22 months, the growing animals take part in bringing food to the young animals; at around 30 months they are fully grown. At around 36 to 40 months of age, the males and sometimes the females have to leave their birth clan. At the same age, the first reproduction can take place. In the best-case scenario, the female gives birth every twelve months, but this birth interval can be extended to 41 months.
The known maximum age of an animal in the wild was twelve years, in captivity the life expectancy can be around 29 years.
Interaction with other species
Saddleback hyenas are inferior to lions and African wild dogs and withdraw from these animals. They also avoid contact with spotted hyenas and do not build their burrows like these along rivers in areas where they occur sympathetically , but in drier areas. They are dominant towards leopards , cheetahs and caracals . A strong food competitor is the black-backed jackal , which also often feeds on the remains of other animals. Fighting can sometimes occur between these two species. Even vultures may be competitors for food.
Among ectoparasites , the flea hard Echidnophada larina and a previously unknown species of louse flies are known , while the tapeworm Taenia hyaenae and the nematode Spirocerca lupi are known to endoparasites .
Saddleback hyenas and humans
Saddleback hyenas have a large range, but have very low population densities and are therefore rare. Their body parts are sometimes used for medicinal purposes or in rituals, but far less often than with the striped hyena. They still have a bad reputation in southern Africa and are considered cowardly or stupid animals. They are often accused of killing pets, also because they are sometimes seen eating the carcasses. Although it can occasionally happen that black hyenas kill and eat domestic animals, this does not happen to an extent that endangers the overall population. Regardless of this, they are shot, poisoned or hunted with dogs by ranchers. Further threats are the shrinking and fragmentation of their living space and road traffic. This danger 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. Svalbard hyenas do not appear to be aggressive towards humans, nothing has been known about unprovoked attacks.
They are found in a number of protected areas in South Africa, Namibia and Botswana. The total population is estimated at 5,000 to 8,000 animals, but due to the nocturnal and spacious way of life, the number could be higher than previously known. The IUCN lists the species as " near threatened " when the population is falling .
Systematics
There are two scientific names for the hyena: Parahyaena brunnea and Hyaena brunnea . The first descriptor , Carl Peter Thunberg , classified it in the genus Hyaena and thus in the same genus as the striped hyena ( Hyaena hyaena ). In 1974, Hendey questioned the close relationship of the two, he suspected that the black hyena was more closely related to the extinct genus Pachycrocuta and therefore classified it as its subgenus Parahyaena . This separation was confirmed by Werdelin and Solounias in 1991, but they elevated Parahyaena to the rank of a separate genus.
Based on morphological and molecular data, it is now considered certain that the striped hyena is the closest living relative of the black horned hyena and that the two species thus form sister taxa . In some taxonomies, membership of the genus Hyaena is maintained due to this relationship, for example by WC Wozencraft. Other works refer to morphological differences and lead the black hyena in its own genus Parahyaena . The differences lie in the construction of the premolars and other details of the skull structure - for example, in Parahyaena the first upper premolar is smaller, the palate extends further back and the atlas and axis overlap longer. The two species were separated around 4.2 million years ago.
The black hyena itself is monotypical , meaning that no subspecies are recognized.
literature
- Kay E. Holekamp and 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.
- MGL Mills: Hyaena brunnea. In: Mammalian Species 194 (1982), pp. 1-5. PDF
- Ronald M. Nowak: Walker's Mammals of the World . Johns Hopkins University Press, 1999 ISBN 0-8018-5789-9 .
Individual evidence
- ↑ Figures from Holekamp & Kolowski (2009), p. 258.
- ↑ Mills (1982), p. 4.
- ↑ a b c Parahyaena brunnea in the IUCN Red List of Threatened Species . Retrieved September 6, 2009.
- ↑ a b c d e Holekamp & Kolowski (2009), p. 259.
- ↑ Holekamp & Kolowski (2009), p. 256.
- ↑ all figures from Holekamp & Kolowski (2009), p. 260.
- ↑ Nowak (1999), p. 790.
- ↑ a b Brown Hyaena ( Parahyaena brunnea ) on Hyaena Specialist Group ( Memento of the original from October 28, 2009 in the Internet Archive ) Info: The archive link has been inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. , accessed September 9, 2009.
- ↑ Mills (1982), p. 3.
- ↑ Holekamp & Kolowski (2009), p. 251.
- ^ QB Hendey: The late Cenozoic Carnivora of the southwestern Cape Province . In: Ann. South Afr. Mus. 63 (1974), pp. 1-369.
- ↑ L. Werdelin and N. Solounias: The Hyaenidae: Taxonomy, systematics and evolution. In: Fossils and Strata 30 (1991), 1-104.
- ↑ a b 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.
- ^ WC Wozencraft: Order Carnivora. In DE Wilson and DM Reeder (eds.): Mammal Species of the World ., 3rd edition. Johns Hopkins University Press, Baltimore 2005, ISBN 0-8018-8221-4 , pp. 532-628.
- ↑ e.g. Nowak (1999) or Holekamp & Kolowski (2009).
- ↑ Nowak (1999), p. 788.
