The spotted hyena (Crocuta crocuta) lives in large, stable, matriarchal groups known as clans, where females dominate all males. This competitive and cooperative environment demands sophisticated methods of information exchange. Hyenas constantly communicate their social rank, emotional state, and territorial boundaries to maintain order. Their communication system is multimodal, relying on visual cues, a diverse vocal repertoire, and chemical signals.
Visual Signals and the Role of the Tail
Hyenas do not wag their tails like domestic dogs as a sign of excitement or greeting. Instead, the hyena tail functions as a precise visual semaphore to communicate social status and intent over short distances. Its position is a critical indicator of the individual’s current social standing and psychological state within the dominance hierarchy.
A tail hanging loosely indicates a neutral or relaxed state. Conversely, a tail held high or carried forward over the back signals alertness, excitement, or dominance, often seen when asserting itself or approaching a novel situation. When aggressive, a hyena may display a “bristle tail,” where the tail is lifted and the hairs are erected like a bottlebrush, intended to make the animal appear larger and more intimidating.
Submission is signaled by the opposite action: the tail is curled tightly below the belly, paired with postures that minimize the hyena’s size. Visual communication also encompasses the ears, mane, and entire body posture. A hyena asserting dominance holds its head high, cocks its ears forward, and erects its mane—a behavior known as piloerection—to exaggerate its physical size.
A subordinate hyena approaching a higher-ranking clan member flattens its ears back and may lower its body, sometimes walking on the knees of its forelegs in an extreme display of submission. These signals are often combined, such as when a low-ranking individual pairs flattened ears with a head-bobbing gesture to signal submissive intent during an encounter. Because hyenas frequently operate at night, these visual signals often reinforce messages conveyed through sound or smell.
The Hyena Vocabulary: Decoding Auditory Communication
Spotted hyenas possess a complex vocal repertoire, using a wide array of calls across varying distances and social contexts. The most recognizable is the “whoop,” a loud, long-distance call that can travel several kilometers. Hyenas use whoops to announce their presence, recruit clan members to a kill, or coordinate movements across their territories.
Variations in the whoop’s pitch and duration signal the individual’s age, identity, and social rank. Dominant females often engage in the longest bouts of whooping to advertise their superior status. This long-range communication is crucial for a species that operates in a fission-fusion society, where individuals frequently separate to hunt before coalescing as a group.
The “giggle” or “laugh” is often misunderstood by humans, but it is a high-pitched, staccato vocalization that signals frustration or anxiety. This sound is most frequently heard during feeding frenzies when hyenas compete for a carcass, and it is a sign of subordination. The pitch of the giggle signals the hyena’s age and social rank, allowing clan mates to assess the severity of the individual’s distress.
Hyenas also use short-range sounds for close interactions. Soft grunts are used by mothers to call their cubs, while growls and whimpers are emitted when an animal is attacked or threatened. This diverse auditory vocabulary allows for social coordination, enabling hyenas to communicate intentions and emotional states to maintain group cohesion.
Scent and Status: Chemical Communication
Chemical communication provides the third major modality, offering a persistent, long-lasting signal vital for territorial defense and individual recognition. The primary method is “pasting,” which involves depositing a viscous secretion from the anal pouch onto grass or other substrates. This strong-smelling paste is rich in lipid sebum and epithelial cells, acting as a chemical signature.
Pasting is performed by the hyena lowering its hindquarters into a semi-squatting position and walking forward while everting the anal pouch to smear the paste. This scent marking, along with communal latrines and secretions from glands on the feet, delineates and defends the clan’s territory boundaries. Since the scent can last for weeks, it provides a warning to neighboring clans.
The paste’s chemical composition is unique to each clan, influenced by microbial communities within the anal glands. Encountering a paste mark allows a hyena to gather data, including whether the marker is a clan member or a foreign intruder. Within the clan, the scent communicates an individual’s identity, sex, and current reproductive status. Dominant hyenas scent-mark more frequently than subordinates, reinforcing their higher social standing.