The
Hyaenidae ( ) is a
mammalian family of order
Carnivora. The Hyaenidae family, native to both
African and
Asian
continents, consists of four living species, the
Striped Hyena and
Brown
Hyena (genus
Hyaena), the
Spotted Hyena (genus
Crocuta), and
the
Aardwolf (genus
Proteles).
Evolution

Skull of
Hyaena eximia

Crocuta macrodonta skull
fossil
Hyenas seem to have originated 26 million years ago from arboreal
ancestors bearing similarities to the modern
Banded Palm Civet.
Plioviverrops, one of the earliest
hyenas, was a lithe
civet-like creature that
inhabited
Eurasia 20-22 million years ago.
Details from the
middle ear and dental
structure marked it as a primitive hyena. This genus proved
successful, its descendants flourishing with more pointed jowls and
racier legs, much as the
Canidae had done in
North America.
Fifteen million years ago, dog-like hyenas flourished, with 30
different species being identified. Unlike some of their modern
descendants, these hyenas were not specialized bone-crushers, but
were more nimble, wolf-like animals. The dog-like hyenas had
canid-like molars, allowing them to supplement their carnivorous
diet with vegetation and invertebrates.
Five to seven million years ago, the hyenas were outcompeted by
canids traveling from North America to Eurasia via the
Bering land bridge.The ancestral
aardwolves survived by having adapted themselves to
an insectivorous diet to which few canids had specialized. Some
hyenas evolved bone-crushing teeth, which allowed them to avoid
competition with the canids, resulting in the hyenas eventually
outcompeting a family of similarly built bone-crushers called
"
percrocutoids". The percrocutoids
became extinct 7 million years ago, coinciding exactly with the
rise of bone-crushing hyena species.
Unlike the canids who flourished in the newly colonized Eurasian
continent, only one hyena species, the
cheetah-like
Chasmaporthetes, managed to cross to
North America. It became extinct 1.5 million years ago.
The peak diversity of the Hyenidae was during the
Pleistocene, with 4 genera and 9 species of
hyena. The bone-crushing hyenas became the Old World's dominant
scavengers, managing to take advantage of the amount of meat left
over from the kills of
sabre-toothed
cats. One such species was
Pachycrocuta, a 200 kg (440 lb)
mega-scavenger that could crush
elephant
bones. As the sabre-toothed cats began to die out and be replaced
by short-fanged felids that were more efficient eaters, more hyenas
began to hunt for themselves and began evolving into new species,
the modern Spotted Hyena being among them.

200 px
Genera of the Hyaenidae (extinct and recent)
The list follows McKenna and Bells
Classification of
Mammals for prehistoric genera (1997) and Wozencraft (2005) in
Wilson and Reeders
Mammal Species of the World
for extant genera. The Percrocutids are, in contrast to McKenna and
Bell's classification, not included as a subfamily into the
Hyaenidae, but as the separate family
Percrocutidae. Furthermore, the genus
Paracrocuta, to which the living
brown hyena belongs, is not included into the
genus
Pachycrocuta, but in the genus
Hyaena. The
Protelinae (Aardwolves) are not treated as a separate subfamily,
but included in the Hyaeninae.
- Family Hyaenidae
-
- †Subfamily Ictitheriinae
- †Herpestides (Early Miocene
of Africa and Eurasia)
- †Plioviverrops (including
Jordanictis, Protoviverrops,
Mesoviverrops; Early Miocene to Early Pliocene of Europe,
Late Miocene of Asia)
- †Ictitherium
(=Galeotherium; including Lepthyaena,
Sinictitherium, Paraictitherium; Middle Miocene
of Africa, Late Miocene to Early Pliocene of Eurasia)
- †Thalassictis (including
Palhyaena, Miohyaena, Hyaenictitherium,
Hyaenalopex; Middle to Late Miocene of Asia, Late Miocene
of Africa and Europe)
- †Hyaenotherium (Late
Miocene to ?Early Pliocene of Eurasia)
- †Miohyaenotherium
(Late Miocene of Europe)
- †Lychyaena (Late Miocene of
Eurasia)
- †Tungurictis (Middle
Miocene of Africa and Eurasia)
- †Proictitherium (Middle
Miocene of Africa and Asia, Middle to Late Miocene of Europe)
- Subfamily Hyaeninae
- †Palinhyaena (Late Miocene
of Asia)
- †Ikelohyaena (Early
Pliocene of Africa)
- Hyaena (=Euhyaena,
=Hyena; including brown
Hyena, Pliohyaena, Pliocrocuta,
Anomalopithecus) Early Pliocene (?Middle Miocene) to
Recent of Africa, Late Pliocene (?Late Miocene) to Late Pleistocene
of Europe, Late Pliocene to recent in Asia)
- †Hyaenictis (Late Miocene of
Asia?, Late Miocene of Europe, Early Pliocene (?Early Pleistocene)
of Africa)
- †Leecyaena (Late Miocene
and/or Early Pliocene of Asia)
- †Chasmaporthetes
(=Ailuriaena; including Lycaenops, Euryboas; Late
Miocene to Early Pleistocene of Eurasia, Early Pliocene to Late
pliocene or Early Pleistocene of Africa, Late Pliocene to Early
Pleistocene of North America)
- †Pachycrocuta (Pliocene
and Pleistocene of Eurasia and Africa)
- †Adcrocuta (Late Miocene of
Eurasia)
- Crocuta
(=Crocotta; including Eucrocuta; Late Pliocene to
recent of Africa, Late Pliocene to Late Pleistocene of
Eurasia)
- Proteles (=Geocyon;
Pleistocene to Recent of Africa)
Appearance and biology
Although hyenas bear some physical resemblance to
canids, they make up a separate
biological family that is most closely
related to
Herpestidae (the family of
mongooses and
meerkats), thereby falling within the
Feliformia. All species have a distinctly
bear-like gait, due to their front legs being longer than their
back legs. The
Aardwolf, Striped Hyena, and
Brown Hyena have striped pelts and manes lining the top of their
necks which erect when frightened. The Spotted Hyena's fur is
considerably shorter and spotted rather than striped.
Spotted Hyenas and, to a lesser extent, Striped and Brown Hyenas,
have powerful
carnassial teeth adapted
for cutting flesh and
premolars for
crushing bone. Spotted Hyenas have a strong bite proportional to
their size, but the view that they have the strongest bite is a
myth; and a number of other animals (including the
Tasmanian devil) are proportionately
stronger. The Aardwolf has greatly reduced cheek teeth, sometimes
absent in the adult, but otherwise has the same dentition as the
other three species. The
dental formula
for all hyena species is:
Labiolingually, their
mandibles are much
stronger at the
canine teeth than in
canids, reflecting the fact that hyenas crack bones with both their
anterior dentition and premolars, unlike canids which do so with
their post-carnassial molars. Like
felids,
hyenas lack the rearward molars of canids and vivverids. By
organising their teeth so that the bone-crushing premolars do not
interfere with the meat-slicing carnassials to the rear, hyenas can
crush bone without blunting the carnassials' blades.
Spotted Hyena societies are more complex than those of other
carnivorous mammals and have been reported to be remarkably similar
to those of
cercopithecine primates
in respect to group size, structure, competition, and cooperation.
One indication of hyena intelligence is that they will move their
killed prey closer together to protect them from
scavengers. Another indication is their strategic
hunting methods.
The majority of hyena species show little
sexual dimorphism, with males being only
slightly larger than the females. The Spotted Hyena is an exception
to this, with females larger than males. One unusual feature of the
Spotted Hyena is that females have an enlarged
clitoris, called a
pseudo-penis, demi-penis, or sometimes
mistakenly referred to as a nanophallus. Female hyenas give birth,
copulate, and urinate through their protruding genitalia, which
stretches to allow the male penis to enter for
copulation; it also stretches during birth. The
anatomical position of the genitalia gives females complete control
over which males are allowed to mate with them.
Researchers originally thought that one cause of this
characteristic of the genitals was
androgens that were introduced to the fetus very
early on in its development. However, it was discovered that when
the androgens were held back from the female
fetus, the development of her genitalia was not
altered. Spotted Hyenas have a
matriarchal social structure that some
biologists speculate evolved because it is in the best interests of
the female hyena to dominate the male hyena as it provides no
assistance in rearing the
cubs.
All species excrete an oily, yellow substance from their
anal glands onto objects to mark their
territories. When
scent marking the
anal pouch is turned inside out, or everted. Hyenas also do this as
a submissive posture to more dominant hyenas. Genitals, the anal
area and the anal glands are sniffed during greeting behavior in
which each hyena lifts its leg and allows the other to sniff its
anal sacks and genitals. All four species maintain
latrines far from the main denning area where
dung is deposited. Scent marking is also done
by scraping the ground with the paws, which deposits scent from
glands on the bottoms of the feet. Hyenas do not raise their legs
when urinating as male or dominant canids do.
Unlike the canids, hyenas do not
regurgitate or carry back food in their stomachs
for their young because of the speed with which the food is
digested by the adults.
Hyenas can carry strains of
rabies but not
develop symptoms.
Habitat and distribution
Three of the four species of hyena are restricted to sub-Saharan
Africa, where they live in drier environments
such as
savannah, bushland and desert. The
fourth species, the Striped Hyena, is found in northern and eastern
Africa as well as in Asia from the Middle East to India.
Dietary habits
Except for the aardwolf, all living hyena species are hunters and
scavengers. They have extremely strong jaws in relation to their
body size and have a very powerful
digestive system with highly acidic fluids,
making them capable of eating and digesting their entire prey,
including skin, teeth, horns and bones. Hair and hooves are usually
regurgitated. Because their digestive system deals very well with
bacteria, they have no aversion to and
readily eat
carrion.
The Spotted Hyena is primarily a predator, unlike some of its
cousins. Spotted Hyenas are successful
pack
hunters of small to large sized
ungulates, and are the most abundant carnivores in
Sub-Saharan Africa.
Because the
aardwolf is a specialized
feeder of
termites, it lacks the size and
physical power of its cousins.
In culture
Many cultures have historically viewed the hyena in a bad light.
Negative associations have generally stemmed from hyenas' tendency
to scavenge
grave for food. They are
one of the few creatures naturally suited for this, due to their
ability to devour and digest every part of a carcass, including
bone. As such, many associate hyenas with gluttony, uncleanliness
and cowardice. The word
hyena is derived from the
Greek hyaina, meaning "pig",
and has a long association with cruelty, treachery and greed.
African attitudes toward hyenas are little better than those held
in the
European cultures. The
Bouda is a mythical tribe reputed to house members
able to transform into hyenas.
Belief in "Werehyenas" is so entrenched within the
traditional lore of the Bornu people of
north-eastern Nigeria
, that their
language even contains a special word, bultungin, which
translates as "I change myself into a hyena".
In Malawi, in the local language large hyenas reputed to be a
man-eater were called
lipwereri
and the ordinary hyena was called a
fisi.
The haunting laughter-like calls of the Spotted Hyena inspired the
idea in local cultures that they could imitate human voices and
call their victims by name. Hyenas are also associated with
divination and sometimes thought of as
tools of
demons and
witches. In
African folklore,
witches and sorcerers are thought to ride hyenas or even turn into
them.
Early naturalists thought hyenas were
hermaphrodites or commonly practiced
homosexuality, largely due to the female
Spotted Hyena's unique
urogenital system. According to
early writings such as
Ovid's
Metamorphoses and the
Physiologus, the hyena continually changed
its sex and nature from male to female and back again. In
Paedagogus,
Clement of Alexandria noted that the
hyena (along with the
hare) was "quite obsessed
with sexual intercourse." Many Europeans associated the hyena with
sexual deformity,
prostitution and
deviant sexual
behavior.
Hyenas (usually "Laughing Hyenas") have been used in animated
movies many times as well as having been rendered in live action
films, commonly cast as hysterical and unhinged villains. Examples
include
Shenzi, Banzai and Ed
from the
Disney animated film The
Lion King, one ball-playing individual in
Bedknobs and Broomsticks, the
Joker's pets,
Bud and Lou, and the laughing Hyena in 'The Lady
and the Tramp'.
See also
References
- Malcolm C. McKenna, Susan K. Bell: Classification of
Mammals: Above the Species Level in Columbia University Press,
New York 1997, 631 Seiten, ISBN 0-231-11013-8
- Ancient Worlds News - Marsupial has the deadliest
bite - 04/04/2005
- Social Hierarchies Feeding Behavior in the Spotted
Hyena
- Online etymology dictionary: Hyena
- lycaon
External links