HE IS a hot-blooded, 30-year-old male in peak physical condition. He has mucus oozing from his cheeks and green urine streaming down his legs. His penis has a green sheen to it and he gives off a smell that can be picked up half a mile away. He wafts his ears back and forth and makes a low rumble. He looks confident: after all, many females find him irresistible.
Sounds familiar? Hopefully not. He is a male elephant in musth – something like a state of rut. Sexually mature bull elephants go through musth for a one to two-month period every year. They don’t exactly hide it, excreting a cocktail of chemicals from a bulbous gland on their cheeks that can swell to the size of a basketball, passing more than 300 litres of urine a day (equivalent to 24 buckets), and – not surprisingly – smelling like a herd of goats. What’s more, during this dramatic advertisement of his sexuality the male appears to undergo something of a personality change; indeed, the word musth is derived from a Persian word meaning drunk. They become very aggressive and obsessed with sex, probably as a result of their high testosterone levels, which can increase by up to 60 times.
What’s it all about? Musth is the elephant version of expensive aftershave and a flash car. It is thought to inform males and females alike of an elephant’s age, status and reproductive health, and also increases a male’s chances of reproductive success. The big question is how a few secreted chemicals can convey so much information. A recent study has cast some light on this: it turns out that the signals communicated by an elephant in musth are extremely precise.
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“Musth is the elephant version of aftershave and a flash car”
The key is a chemical called frontalin, a pheromone secreted by sweat glands on the elephants’ cheeks during musth and also present in the breath and urine. Frontalin is common in the insect world – bark beetles use it as a pheromone too, for example. It exists in two “chiral” forms that are molecular mirror images of each other. Researchers led by David Greenwood at the Mount Albert Research Centre in Auckland, New Zealand, have found that elephants in musth release both chiral forms of frontalin, and that the ratio depends on the elephant’s age and the stage of its musth cycle (Nature, vol 438, p 1097).
This means that a male elephant can never hide the truth about his prowess: females can accurately assess his reproductive fitness and male contemporaries can judge how strong he is before attempting to pick a fight. Such precise chemical signalling has not yet been identified in other mammals, but the chances are that elephants are not the only ones to use it. Perhaps we humans create similar signals, but have long since lost the ability to interpret them.
