FUNNY CREATURES OF NAIROBI NATIONAL PARK- THE LAUGHING HYENAS!!! – BY GARETH JONES

Early morning drives through the park are events that have a feeling of the unexpected. Such an event happened near junction No7, after we had entered from the east gate. Suddenly four hyenas appeared on the road, I immediately stopped and switched off the engine. The hyenas hesitated and observed us for a while, and then slowly moved up the road towards us. They moved off into the long grass for a brief moment and returned into the road behind us, before walking away. Wow what a sighting! Hyena sightings in the Nairobi Park are fairly rare but always unique. It has been noted however that the hyena population within the Nairobi National Park is slowly increasing.

Spotted Hyenas (Latin – Crocuta Crocuta) have a reputation for being scavengers, however they play a vital role in nature by cleaning dead remains of animals, and in doing so reduce possibilities of diseases. Sadly in Nairobi some of the Hyenas do wander out of the park and forage for food at night, often with tragic consequences, such as poisoning. However they are also very efficient hunters, often running down their prey in packs. Their eerie “whoop…whoop” call is often heard late at night in some residential areas. They also have a strange almost repetitive cackling sounding noise that sounds like a hysterical laugh, especially when they are excited as a pack around a kill or while hunting. The hysterical laughing sound is actually not because they are having fun, but rather it is a serious communication to other hyenas that they want something they have, like a bone or piece of meat at a kill. Spotted hyenas have a rich vocal repertory; they emit about a dozen distinct vocalizations, most of which can be modulated in various ways to alter their meaning to listeners. Spotted hyenas are often called “laughing hyenas” because their giggle vocalization sounds very much like hysterical human laughter. The giggle is a loud, high-pitched rapid series of staccato “hee-hee-hee” sounds. Brown and striped hyenas do not produce giggle or whoop calls, or in fact many vocalizations at all, so the giggle truly appears unique to spotted hyenas. Hyenas are most likely to giggle after being attacked and while being chased around by another hyena who wants the carcass part the giggler is carrying around in its mouth. The giggling hyena seems to be signaling that it wants its social partner to desist and leave it alone. Unfortunately, giggling by a hyena carrying food tends to attract other hyenas to it, and actually often results in even more harassment directed at the caller.

When hyenas want to coordinate clan mates to form coalitions against lions, they produce a vocalization, called “lowing,” that sounds very much like the mooing of a cow. Spotted hyenas produce “alarm rumbles” to signal danger; these are deep, rapid staccato sounds that are heard most frequently when a lion or a human on foot appears over a rise within sight of a group of hyenas. When mother hyenas want to call their infants up out of a den, they groan into the den hole, and their cubs soon pop out on the surface. When cubs are hungry, they produce a grating fingernails-on-blackboard sound, with their lips pulled back from their teeth, to encourage their mother to lie down so they can nurse. We call this annoying sound a “squitter”.

The hyena’s whoop vocalization is a series of discrete calls produced in a bout of sound that can travel distances of more than two miles. The voices of adults are deep, but the whoops emitted by the cubs at this buffalo kill were very high-pitched. The rate at which whoops are produced within a bout communicates emotional intensity to listeners.

Spotted hyenas actually use a “laughing language” to communicate with each other, scientists have learned. They are famous for their maniac giggling, especially around a kill. But although they might appear to treat the business of survival as a joke, the laughing sounds have a serious purpose. New research has shown that hyena laughter encodes complex information about age, status and identity. It may also signal a call for help and co-operation in food contests. Dr Frederic Theunissen, from the University of California at Berkeley, said: “The hyenas laugh gives receivers cues to assess the social rank of the emitting individual.” This may allow hyenas to establish feeding rights and organise their food-gathering activities. They found that variations in the giggles’ pitch and timbre helped the animals establish social hierarchies.

Laughter pitch indicated a hyena’s age, while differences in the frequency of notes encoded information about dominant and submissive status. Giggles carried a “broad range of messages” that were informative enough to play a role in social interactions, the scientists reported in the journal BMC Ecology. They pointed out that hyenas were highly intelligent animals capable of understanding complex relationships. It has been said that the giggles may also convey a message of “frustration” and a request for help when competing with other predators such as lions. “Lions often eat prey previously killed by hyenas”, he said. “A solitary hyena has no chance when confronted by a lion, whereas a hyena group often can ‘mob’ one or two lions and get their food back. Giggles could therefore allow the recruitment of allies.

“Co-operation and competition are everyday components of a hyena’s life. When hearing a giggling individual, clan-mate hyenas could receive information about who is getting frustrated (in terms of individual identity, age, status) and decide to join the giggler, or conversely to ignore it or move away.” The communication research was done on captive hyenas so the team now plans to carry out further similar research while observing hyenas in the wild. Hyenas are Africa’s most common large carnivore and one species is also found in Asia.

It’s always best to expect the unexpected, rewards will come in time. Maybe you will have a laugh as well?

The park is open daily from 06h00 to 19h00.

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