Although Charles Darwin noted in ‘The descent of man’ that monkeys have a “strong taste” for “spirituous liquors” and beer, most studies carried out since have concluded that animals have no interest in alcohol or even a distinct aversion to it.
But now a study published in Scientific American has shown that pen-tailed tree shrews can enjoy a tipple without the side effects. These tiny animals frequent the bertram palm, returning regularly to drink its nectar. Scientists discovered that the nectar contains 3.8 per cent alcohol, making it a similar strength to some beers.
The tree shrews regularly enjoy the equivalent of nine alcoholic drinks a night. Despite an apparent neurological effect in enticing the animals back to the plant for more, they exhibited no signs of intoxication. They, and six other species of mammals living in the Malaysian rainforest, get to enjoy their booze in exchange for acting as the plant’s pollinators.
The scientists proposed that their findings support the theory that man’s attraction to alcohol evolved from a time when people roamed forests in search of energy-rich plants. The aroma of alcohol might have signalled that a fruit had reached its peak energy content.
Egyptian fruit bats occasionally find themselves flying under the influence of alcohol as their staple diet ripens, but they know how to sober themselves up. They steady their flight path with the help of sugars — particularly fructose, which causes their alcohol levels to fall faster than glucose does.
An experiment that involved giving monkeys alcohol found that they exhibit drunken behaviour similar to that of humans. When 1,000 green vervet monkeys were given alcohol they could be divided into four main categories: binge drinkers, steady drinkers, social drinkers and teetotallers.
The vast majority were social drinkers. These indulged in moderation and only when with other monkeys. But 15 per cent drank regularly and heavily and 5 per cent were classed as “seriously abusive binge drinkers”, liable to get drunk, start fights and consume alcohol until passing out. Most heavy drinkers were young males.
The monkeys, which share 96 per cent of their genetic make-up with humans, were used to investigate drinking behaviour in humans and to identify possible “alcohol genes”.
