Hyenas comprise their own family in the mammalian order Carnivora. Whereas they are sometimes mistaken for dogs, hyenas actually have more in common with cats than with dogs, and the hyena family is most-closely related to the carnivore family containing mongooses.
In the hyena family, there are four species of hyenas: spotted (Crocuta crocuta), striped and brown hyenas, and a smaller species known as the aardwolf. For more information, visit the Kay Holekamp Laboratory Web site.
One myth about spotted hyenas is that they are strictly scavengers. However, hyenas in the Masai Mara run down and kill 90 percent of their own food, so they have proven to be efficient hunters. When dealing with lions, the hyena's primary adversary, hyenas are only successful in stealing food from lions when no male lions are present and when the hyenas outnumber the female lions by at least four to one.
Adult hyenas reach a maximum weight of 185 pounds and a maximum shoulder height around 3 feet. The massive jaw muscles generate roughly nine thousand Newtons of bite force at their primary bone-cracking teeth - several times the amount of bite force generated by human jaws - allowing hyenas to crack open large bones to get to the fat-rich marrow in the center. Holekamp and her students have observed adult hyenas cracking opens giraffe leg bones up to three inches in diameter.
A single hyena can bring down an animal several times its size. Hyenas can digest virtually all parts of their herbivore prey except horns and hooves. Of interest to Holekamp and her students is how hyenas can consume a vast array of foods, including many that would make a human violently ill, without getting sick or contracting diseases as often happens as other animals. Their robust immune and digestive systems have scientists looking for answers.
Holekamp has documented that an adult hyena can eat up to 30 pounds of meat in only ten minutes. Additionally, she has timed a group of 23 hyenas completely consuming a full-grown wildebeest in only 13 minutes.
A hyena's maximum speed is roughly 35 miles per hour and they can chase their prey for several miles - long after other predators like lions and cheetahs would be forced to give up.
Female hyenas have an elongated clitoris that is six to seven inches long in an adult. This feature looks much like a penis and accounts for ancient beliefs that hyenas are hermaphrodites. Female hyenas give birth through the vaginal canal which exits through the elongated clitoris.
Spotted hyenas live in social groups, called "clans," that may contain up to 80 individuals. The complexity of their social hierarchy and behaviors rival those found in old world primates, and thus represent a primary research area for the Holekamp Lab.
Social dominance plays a primary role throughout a hyena's entire life and this is primary research area for the Holekamp Lab.