The Spotted Hyena

By Chelsea Landwehr 2013

The Spotted Hyena

Spotted Hyena's live in a terrestrial environment and are found in Asia and Europe but most commonly in Africa where the they are the most abundant large carnivore. Some of the many places in Africa where they are found include,Botswana, Kenya, Cameroon and Zimbabwe. More specifically, their habitats include places like the Savannah, grasslands, woodlands,forest edges, sub deserts and mountains up to 13,000 feet. Some challenges that its inhabited environments place on the hyena include, the threat of loss of habitat. This is as a result of the human population expanding and the growth of agriculture, settlements and roads too. Activities like cattle farming involve the destroying of hyena habitat and the spaces in which they are able to freely roam. Another pressure is the one caused by humans, being that cattle farmers persecute large carnivores such as hyenas.  Illegal poaching of wild animals is also a threat; while hyenas are not always targeted by poachers, they are often trapped by cruel snares.

Below is a map of the common areas in Africa Spotted Hyena are found.

Fertlisation

The spotted hyena is a non-seasonal breeder . The spotted hyena is promiscuous, as members of both sexes may copulate with several mates over the course of several years- no enduring or constant bond between two hyenas is formed. Hyena's reproduction will produce between one and three cubs so it is likely that several (1-4) female gametes will be released to be fertilised each estrous cycle. An advantage of this outcome is that if a predator kills the offspring it wont be a waste of breeding because other cubs will be alive to grown. Also it gives the mother more of an opportunity to care for her small amount of cubs however, a disadvantage is that there will be less offsprings to keep the species alive.

The process by which a spotted hyena reproduces is  done internally via cross-fertilisation. Usually the male hyena will be an immigrant to the female's clan as a result of it leaving its natal group. The advantages for leaving the natal group and joining a new clan is that immigrants can take advantage of mating opportunities that are unavailable to males in their natal clans. Female spotted hyenas have complete control over who they mate with, and they rarely mate with adult natal males who are reproductively mature but have not yet dispersed.

Usually males will show submissive behaviour when approaching females in heat, even if the male outweighs its partner, then a female hyena will lower her head as head lowering by an estrous female signals to the male that she will not bite him, and that it is now safe for him to mount her.

Once mounted the intromission of a male hyena his is no easy feat, because successful mating requires that the male insert his erect penis into the female’s “pseudo-penis” which is flaccid during copulation however its only opening, points forward and downward, so the male must hop around behind the female while he squats behind her, thrusting blindly upward and backward, to achieve intromission (or penetration).

A female spotted hyena's genitals are typical by mammalian standards, however physically they resemble those of a male. The clitoris of the hyena is greatly enlarged to look like a penis and is capable of erection. Through this pseudo-penis the female will urinate, copulate and give birth. They also don't have an external vagina as their labia has fused along with some enlarged tissue to resemble what looks like a scrotum and testis.

Furthermore, research has revealed that the glans of the male’s penis swells slightly in the female’s reproductive tract, such that the sex partners remain in a brief “copulatory lock” for some minutes after the male ejaculates. The mating couple is therefore completely vulnerable to lions and other dangers during this “lock” period. This vulnerability suggests why the hyenas appear to seek out the most private and safe places possible in which to copulate.

A female will be likely to mate multiple times during her estrous period (heat) so she will become pregnant.

Below is a picture of two Hyena's mating.

Development

The embryo of the spotted hyena develops within its mothers womb- this is described as viviparity. The gestation period for a spotted hyena is between 90 and 110 days. A disadvantage of this length of time is that less offsprings are produced however an advantage is that the mammals will be a lot more developed when they are born than other marsupials and amphibians, their eyes are open, many of their teeth are already in, and they are quite active, pulling themselves along with their front paws. Newborns are born all black and weigh about 1.5 kg. . The internal development of the fetus coincides well with its environment because it protects the young babies from predators like lions and humans and it is the best option to develop a baby as there isn't much water or a watery environment in Africa.

Below of a video of a female spotted hyena giving birth. At 0:20 it is visible that the amniotic sac has burst and the baby is ready to be born.

Parental Care

Spotted hyenas fall into K-selection of parental care. The mother handles the majority of parental care, such as building the den, protecting the young, and nursing. The male rarely participates, but if he is around when the cubs are still growing, he may occasionally play with and chase them. Cubs begin to eat meat from kills near the den at about 5 months, but they are suckled for as long as 12 to 18 months which is quite long for carnivores. This is a necessity, as most kills are made far from the den, and hyenas, unlike other hunting dogs, do not bring back food and regurgitate it for their young. At about 1 year, cubs begin to follow their mothers on their hunting and scavenging forays. Until then, they are left behind at the den with a baby-sitting adult. Hyenas use a high level of parental care as the don't produce many cubs in a litter also making them have a lower mortality rate however, usually if two cubs of the same sex are born, they will fight until the death of one- the surviving receiving a high amount of parental care. Spotted hyenas receive a great deal of parental care because they must learn to hunt and eventually care for themselves. Male hyenas leave their natal group in search for a mate so they also need to learn to fend for themselves. This idea had a great advantage because the hyena is equipped to deal with many situations and can hunt for itself without relying on anything.

Below is a mother with her young cub.

Interesting Information

  • When a spotted hyena is in labour her clitoris will rupture to allow the baby to pass through. The resulting wound will then take several weeks to heal.
  • Spotted Hyena can live up to 25 years old.
  • The spotted hyena is very vocal, producing a number of different sounds consisting of whoops, grunts, groans, lows, giggles, yells, growls, laughs and whines as shown below.

Bibliography

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