The spotted hyena (Crocuta crocuta) is a highly successful predator known for its complex social structure, which is dominated by females. Female hyenas are larger and more aggressive than males, a unique trait among carnivores that contributes to their unusual reproductive habits. This female dominance fundamentally shapes every aspect of courtship and copulation. The act of mating is thus a highly controlled and infrequent event.
Mating Frequency and Duration
Spotted hyenas are non-seasonal breeders, meaning mating can occur year-round. However, a female is only receptive during a brief estrous period, typically lasting around two weeks. This reproductive cycle is infrequent, as a female produces a litter only once every 11 to 21 months.
During this short window, successful copulation is not continuous. The female allows the male to mount her multiple times over a span of a few hours, often at night. The actual act of copulation is brief, usually lasting between four and twelve minutes. Multiple short mounts often precede the single, longer mount during which intromission and ejaculation occur.
The Unique Reproductive Anatomy
The female spotted hyena possesses an extraordinary anatomy that makes mating physically challenging. She lacks an external vaginal opening; instead, her labia are fused, creating a structure that resembles a scrotum. Her clitoris is greatly enlarged and elongated, forming a flexible pseudo-penis through which she urinates, copulates, and gives birth.
The pseudo-penis is traversed by the urogenital canal, requiring the male to enter through this structure. The process demands the full cooperation of the female, who must retract her pseudo-penis to expose the opening and allow intromission. This unique anatomical barrier makes forced copulation physically impossible, giving the female absolute control over her choice of mate.
One theory for this masculinized anatomy links it to the high levels of androgens, or male hormones, found in the female’s bloodstream. These hormones are passed to the developing fetus during gestation. The anatomy may also serve as a mechanism to ensure that only persistent and accepted males are able to successfully reproduce.
The Mating Ritual and Social Hierarchy
The process of mating is heavily influenced by the hyena’s strict, female-dominated social hierarchy. Males are significantly smaller and hold the lowest ranks in the clan, meaning they must approach females with extreme caution and submissiveness. To court a female, a male engages in a variety of persistent, low-key behaviors.
These courtship displays include the “approach/avoid” behavior, where the male repeatedly moves toward and away from the female, and various submissive gestures. He may bow, paw the ground, or groom his forelegs to demonstrate non-aggression and deference. The female must inhibit her natural aggression toward the male and adopt a specific, receptive posture for mating to proceed.
Females often prefer to mate with lower-ranking, immigrant males over higher-ranking resident males. These immigrant males are thought to be more successful because they invest more time in building affiliative relationships with females. The male must be patient and position his penis at a precise upward angle to align with the female’s retracted pseudo-penis.
Reproductive Success and Cub Development
Following successful mating, gestation lasts approximately 110 days. Females most commonly give birth to a litter of two cubs, though litters can range from one to four young. The birth process is difficult and dangerous because the cub must pass through the narrow urogenital canal of the pseudo-penis.
Hyena cubs are born in a precocial state, meaning they are relatively advanced at birth with their eyes open and small teeth already erupted. This advanced development is linked to the high levels of androgens the fetuses were exposed to in the womb. Unfortunately, this early maturity often leads to intense and sometimes fatal sibling rivalry, known as siblicide, which can kill up to 25% of cubs in their first month.
The cubs rely on their mother’s milk, which is exceptionally rich in fat and protein, for a prolonged period. Weaning is a slow process that can take 12 to 18 months, representing a high investment of maternal care. Males take no part in raising the young, so responsibility for the cubs’ long development rests entirely on the mother.