Hyenas are not considered dogs, despite common assumptions based on their general appearance and some behaviors. The four extant species of hyenas belong to their own unique biological family, Hyaenidae, which is entirely separate from the Canidae family that includes dogs, wolves, and foxes. This distinction reflects a profound difference in their evolutionary history and fundamental biological blueprint. The persistent confusion between the two groups stems from how unrelated animals can develop similar traits when facing comparable environmental pressures.
The Hyena’s True Family Tree
The scientific classification of hyenas firmly places them outside the dog lineage. Both dogs and hyenas belong to the order Carnivora, which groups together all meat-eating mammals, but the order splits into two distinct suborders: Caniformia and Feliformia.
Dogs, and all members of the Canidae family, fall under Caniformia, the “dog-like” carnivores, a group that also includes bears and weasels. Hyenas are classified within the suborder Feliformia, alongside cats, civets, and mongooses. This means that a hyena is more closely related to a housecat than it is to a wolf or an African wild dog.
The defining characteristic that helps place hyenas in the Feliformia suborder is the structure of their auditory bullae, the bony capsule enclosing the middle and inner ear, which is double-chambered, a trait shared by cat-like carnivores. Their placement in the separate family Hyaenidae underscores their unique evolutionary path.
Why Hyenas Are Often Mistaken for Dogs
The common misconception that hyenas are a type of dog is largely due to a process called convergent evolution. This phenomenon causes unrelated species to independently evolve similar physical characteristics or behaviors because they occupy similar ecological niches.
Hyenas, particularly the spotted hyena, share the general body plan of a cursorial hunter, an animal adapted for running down prey. Their physical characteristics, such as non-retractable claws, large upright ears, and a gait suited for long-distance movement, mimic those found in canids. Additionally, like wolves and African wild dogs, hyenas are highly social animals that live in cooperative groups called clans and engage in group hunting. These shared traits are adaptations to the African savanna environment, leading to the visual and behavioral resemblances.
Biological Traits Setting Hyenas Apart
Despite superficial resemblances, hyenas possess unique biological features that solidify their separate classification. The spotted hyena’s skull and dentition are specialized for extreme bone processing, with jaws that can exert immense force to crush and digest large bones, a capability far exceeding that of most canids. This specialization is supported by a digestive system that can process the dense minerals from bone, allowing the hyena to fully utilize a carcass.
Another biological element is the unique reproductive system of the female spotted hyena. Females possess a long, protruding clitoris, known as a pseudo-penis, which is shaped and positioned exactly like the male organ, and they lack an external vaginal opening. The female must urinate, copulate, and even give birth through this pseudo-penis, a physically demanding process that results in a high mortality rate for first-time mothers and their cubs.
Furthermore, hyena society is strictly matriarchal. Females are larger, more aggressive, and dominate all males, with the lowest-ranking female outranking the highest-ranking male. This social structure is unlike the dominance hierarchies found in canid packs.