Hyenas
Hyenas are carnivorous mammals belonging to the family Hyaenidae, which includes four species: the spotted hyena, striped hyena, brown hyena, and aardwolf. These animals are characterized by their wolf-like body shapes, with distinctively shorter hind legs compared to their front legs. Hyenas are primarily found in grasslands and shrublands across Africa, the Middle East, and Arabia. They are known for their keen senses, especially hearing and smell, and their social structures can vary; some species like spotted hyenas live in packs, while others, such as brown hyenas and aardwolves, tend to be more solitary.
Spotted hyenas are the largest of the species and are often misunderstood as mere scavengers, when in fact they are significant predators of live herbivores. Their hunting behavior typically involves group attacks during nighttime. On the other hand, aardwolves primarily feed on termites and have adaptations for this diet. Hyenas play a vital ecological role by controlling carrion populations and aiding in the health of ecosystems through their feeding habits. Conservation efforts are ongoing, as some species, like the striped and brown hyenas, are considered near-threatened.
Hyenas
Hyena Facts
Classification:
- Kingdom: Animalia
- Subkingdom: Bilateria
- Phylum: Chordata
- Subphylum: Vertebrata
- Class: Mammalia
- Order: Carnivora
- Family: Hyaenidae (hyenas and aardwolf)
- Genus and species:Crocuta crocuta (spotted hyena);Hyaena brunnea (brown hyena),H. hyaena (striped hyena);Proteles cristatus (aardwolf)
- Geographical location: Asia and Africa
- Habitat: Deserts, grasslands, shrubby areas, forests, and mountains
- Gestational period: Depending on species, two to four months
- Life span: Fourteen to twenty-five years in the wild, twenty-five to forty-five years in cap tivity
- Special anatomy: Manes; four- or five-toed paws; hind legs shorter than forelegs; most have teeth able to crush bones, but the aardwolf eats largely insects
Hyenas comprise four carnivore species of the family Hyaenidae, with body shapes similar to wolves; awkward-looking hind legs shorter than the front legs; good hearing; good vision; and a good sense of smell. Sizes range from small aardwolves to large spotted hyenas. All inhabit grasslands and shrubby areas in Africa, the Middle East, and Arabia.
Some species form packs; others live alone. Most scavenge anything they find, including carrion. Aardwolves mainly eat termites. Hyenas mate year round and have two- to four-month gestation periods, depending on species.
As of 2015, the International Union for Conservation of Nature had continued to include the striped and brown hyenas on its watch list as near-threatened animals.
Physical Characteristics of Hyenas
The physical characteristics of three of the four hyena species are exemplified by the spotted hyena, the largest, strongest species. Their maximum length is six feet, height three feet, and weight 175 pounds. Spotted hyena hind legs are shorter than their front legs, making them look awkward. They also have four-toed paws and manes of coarse hair on the neck, shoulders, and back. The adults are a brown-gray with brown spots, and have large heads, bone-crushing jaws, and an eerie, “laughing” cry, like hysterical human laughter.
Laughing (spotted) hyenas were long thought to be carrion-eaters only. It is now clear that they are major predators of live herbivores such as zebras. They attack in packs at night, bite their victims, and hold on until the prey stumbles. They kill by tearing open the belly of the prey. Spotted hyenas kill other carnivores as well, such as striped and brown hyenas.
Striped and brown hyenas have manes, short hind legs, and bone-crushing teeth. They are smaller and less aggressive than laughing hyenas, inhabiting grassy and shrubby areas of Africa, India, and, more rarely, the former Soviet Union (such as Turkmenistan). Their gray-brown, black-striped fur is fine camouflage. Like other hyaenids, striped hyenas eat carrion. They also eat fruit, small mammals, birds, and sometimes large herbivores, such as antelope. They grow to maximum lengths of 5.5 feet, heights of 2.5 feet, and weights of 125 pounds. Spotted hyenas hunt at night in small packs.
Brown hyenas are dark brown with gray heads and striped legs. Their maximum length is 4.5 feet, and they reach 120 pounds. They inhabit the dry, rocky Southern African deserts, usually traveling alone. As scavengers they eat anything available, including carrion and bones picked clean by vultures, using strong teeth to crack bones for marrow.
Aardwolves, honorary hyenas, inhabit much of Africa. They are hyaenid by appearance, as their backs slope down from shoulder to tail due to short hind legs. They have reddish, black-striped fur and manes on their necks and shoulders. When attacked, aardwolves erect the mane to look fiercer and spray evil-smelling musk from perineal glands.
Aardwolves differ from hyenas in having five-toed front feet. Aardwolf teeth are small and suitable only for eating their main food, termites and other insects. Their maximum length is 2.5 feet, their height is 1.5 feet, and their weight is twenty-five pounds. The termites that aardwolves eat are active at night, so aardwolves are nocturnal and eat termites with their long, sticky tongues. Aardwolves live alone and mark territories with musk, denning in empty burrows of other animals.
The Life Cycle of Hyenas
There are similarities and differences in hyena species' lives. Spotted hyenas form groups of up to one hundred: a few males, many females, and numerous young. Females conceive year round, birthing two or three pups that can see and run immediately, after a four-month gestation. Females, larger than males, select short-term mates. Striped hyenas fight within groups, sometimes killing group members. Maximum life spans are twenty-five years in the wild and forty years in captivity.
Like spotted hyenas, striped hyenas mate year round. They live in small groups or alone. A three-month gestation yields two to five young born with the eyes not yet open. Mothers nurse offspring until they can feed themselves. Life spans are up to twenty-five years in captivity. Brown hyena life cycles and reproductive habits are nearly the same as in striped hyenas. However, they live alone except when mating or nursing young.
Aardwolves live in groups. They have a mating season when males fight for females and winners mate. Gestation is two months and yields two to five young, nursed for two months. Aard wolves live for fifteen years in captivity.
Spotted, striped, and brown hyenas eat carrion, preventing its decay and its endangerment of humans and other animals. Aardwolves eat termites, preventing damage to the wilderness and human habitations. These activities are their main ecological function. As spotted and striped hyenas eat live food, they also kill injured or weak members of other species, helping the species eaten to enhance their long-term survival.
Principal Terms
carrion: dead animals
gestation: time in which mammalian offspring develop in the uterus
musk: bad-smelling liquids made to mark territory or for self-defense
perineal: located between scrotum and anus in males or equivalent region in females
Bibliography
Ammann, Karl, and Katherine Amman. The Hunters and the Hunted. Bodley Head, 1989.
Bougrain-Dubourg, Allain. The Tender Killers. Translated by Yann Arthus-Bertran, Vendome, 1985.
Caputo, Robert, and Miriam Hsia. Hyena Day. Coward, 1978.
Mills, Gus, and Heribert Hofer. Hyaenas: Status Survey and Conservation Action Plan. IUCN, 1998.
Mills, M. G. L. Kalahari Hyenas. Kluwer Academic, 1994.
"No Laughing Matter: Unlovable Hyenas Are Threatened in the Wild." Scientific American, n.d., www.scientificamerican.com/article/earth-talks-hyenas/. Accessed 3 Oct. 2016.
Werdelin, Lars, and Nikos Solounias. The Hyaenidae: Taxonomy, Systematics, and Evolution. Universitetsforlaget, 1991.