Hyenas or hyaenas are the animals of the family Hyaenidae of the feliform suborder of the Carnivora. With only four extant species, it is the fifth-smallest biological family in the Carnivora, and one of the smallest in the class Mammalia. Despite their low diversity, hyenas are unique and vital components of most African ecosystems.
Hyenas first arose in Eurasia during the Miocene period from viverrid-like ancestors, and soon became well known as being of two distinct types: the lightly built dog-like hyenas and the robust bone-crushing hyenas. Although the dog-like hyenas thrived 15 million years ago (with one taxon having colonised North America), they became extinct after a change in climate along with the arrival of canids into Eurasia. Of the dog-like hyena lineage, only the insectivorous aardwolf survived, while the bone-crushing hyenas (whose extant spotted, brown and striped hyenas) became the undisputed top scavengers of Eurasia and Africa.
The spotted hyena is a skillful hunter but also a scavenger. Truly an opportunistic feeder, it selects the easiest and most attractive food it may ignore fresh carrion and bones if there is, for example, an abundance of vulnerable wildebeest calves. It consumes animals of various types and sizes (including domestic stock and even other hyenas), carrion, bones, vegetable matter and other animals’ droppings. The powerful jaws and digestive tract of the hyena allow it to process and obtain nutrients from skin and bones.
Hyenas usually bear litters of two to four cubs, which, unlike the other two species, are born with their eyes open. 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, an unusually long time for carnivores. This is probably a necessity, as most kills are made far from the den, and hyenas, unlike jackals and 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 babysitting adult.