Hyenas are distinctive and successful carnivores inhabiting the savanna and scrublands of Africa and parts of Asia. These highly adaptable mammals have developed a unique ecological niche, allowing them to thrive alongside larger predators. To understand their biology, they must be placed within their proper biological classification. All living hyenas belong exclusively to the Family Hyaenidae, a relatively small but highly specialized group of meat-eating animals.
The Hyaenidae Family Tree
The Family Hyaenidae is placed within the Order Carnivora, but its taxonomic placement distinguishes hyenas from the dog family, Canidae, with which they are often mistakenly grouped. Hyenas are members of the Suborder Feliformia, encompassing the “cat-like” carnivores. Their closest relatives include mongooses, civets, and felines. The evolutionary history of Hyaenidae is deep, first appearing in the fossil record about 22 million years ago in Miocene Eurasia.
Early hyenas were smaller and more slender, resembling civets or dogs, and were much more diverse than the modern group. A major climatic shift and the arrival of canids into Eurasia led to the extinction of most of these dog-like hyenas. The lineage that survived were the robust, bone-crushing forms ancestral to the three modern species, alongside a single specialized insectivore. Hyaenidae today represents the remnant of a formerly widespread group that once included at least 24 different species.
The Four Extant Species
The Hyaenidae family contains only four extant species, each representing a unique specialization. The most recognized is the Spotted Hyena (Crocuta crocuta), which is widespread across Sub-Saharan Africa and known for its large size and complex social groups. Its diet is highly varied, as it is both an active predator and a dedicated scavenger.
The other three species are smaller and more solitary. The Brown Hyena (Parahyaena brunnea) is found in the arid regions of Southern Africa, while the Striped Hyena (Hyaena hyaena) has a broader distribution stretching across North and East Africa into parts of Central and Southern Asia. Both the Brown and Striped Hyenas are primarily scavengers, supplementing their diet with fruits, insects, and small vertebrates.
The Aardwolf (Proteles cristata) represents a dietary outlier, as it is a specialized insectivore found in Eastern and Southern Africa. Unlike its relatives, the Aardwolf feeds almost exclusively on termites, consuming up to 300,000 in a single night. This specialized diet means the Aardwolf has evolved away from the powerful jaws and teeth characteristic of the other three bone-crushing hyenas.
Specialized Physical Adaptations
The three bone-crushing species—Spotted, Brown, and Striped Hyenas—share distinctive morphological features centered on physical power and durability. Their most recognizable trait is the sloped body profile, where the forelegs are substantially longer than the hind legs, resulting in high shoulders and a sloping back. This unique build supports a powerful neck and shoulder girdle, which anchors the massive jaw musculature.
The skull is adapted to withstand the forces generated during biting, featuring a vaulted forehead and an elongated frontal sinus that extends over the braincase. This structure acts like an architectural arch, strengthening the skull against the vertical loading and bending stress incurred when cracking large bones. Their dentition is specialized, with robust, conical premolars designed to splinter bone and access the marrow, giving them one of the strongest bite forces among mammals. A highly acidic digestive system allows these hyenas to process nutrients from materials like bone, hooves, and skin that other carnivores typically leave behind.
Complex Social Structures
The Spotted Hyena exhibits one of the most sophisticated social organizations in the animal kingdom, forming large groups called clans that can number up to 80 individuals. These clans are governed by a strict, linear, and profoundly matriarchal hierarchy. Females are larger, more aggressive, and dominant over all males. A female’s rank is inherited directly from her mother, granting her offspring privileged access to resources like food and den sites.
The established social order is so rigid that even the lowest-ranking female outranks the highest-ranking male. Males leave their birth clan upon reaching maturity and must integrate into a new group, starting at the bottom of the social ladder. Maintaining this complex structure involves sophisticated communication, including vocalizations and intricate greeting rituals. These rituals involve specific postures and mutual inspection to reinforce social bonds and power dynamics.
In contrast, the Brown and Striped Hyenas are more solitary, often foraging alone or in small, less-organized groups. The Aardwolf is almost exclusively solitary, only interacting during brief mating periods.