Richard Collins: Berry berry drunk — it's only natural
Bohemian waxwing with rowan berries (Bombycilla garrulus). Rowan berries have been found to contain ethanol concentrations of 0.30%
In vino veritas (in wine there is truth) — Pliny the Elder
Reports of ‘drunk and disorderly’ wild animals surface in the media from time to time. In Nordic countries, large deer get high by eating fermented fruit. They stagger onto roads, causing traffic accidents. Bears and squirrels are also vulnerable to what is, in effect, alcohol poisoning.
Research published in 2020 claimed that we humans are able to consume alcohol thanks to a mutation which seems to have occurred in a great ape ancestor, but the ‘demon drink’ used be regarded as an invention of Satan.
‘Some ungracious pastors’ railed against the evils of intoxication; we had ‘Confirmation pledges’ and ‘Pioneer rallies’. These critics had a point; alcohol had been the scourge of Ireland. "I’m a drinker with a writing problem," declared Brendan Behan.
Nor were we alone in this. Scandinavians were prone to boozing during the long winter darkness. Islam outlaws drinking. Is it, therefore, an ’unnatural practice’ of both man and beast? Are animal alcoholics victims of contact with our decadent civilisation?
‘Moderate drinking’ doesn’t greatly impair the faculties and so might be tolerated, but getting ‘foot-loose’ would be very risky for a wild creature. Not only is an inebriated animal vulnerable on roads, it can easily fall victim to predators such as wolves.
However, animals, great and small, feed on fruits and nectars containing alcohol. So how widespread is boozing among them?
Excited to announce our new paper on ‘The evolutionary ecology of ethanol’ is now out online in @Trends_Ecol_Evo! 🎉
— Anna Bowland (@ACBowland) October 30, 2024
More info below:
https://t.co/8XE9A6bLZU
Anna Bowland and colleagues at Exeter University have just published a paper which addresses some of these questions. Alcohol, they say, is not a newly-invented synthetic drug created by Man. It has been around in the natural world for millions of years. Although toxic in large quantities, drink has a beneficial role to play. Plants are constantly at war with their enemies. They need bacterial and anti-fungal compounds to protect themselves from attack. Yeasts provide these substances, some of which contain alcohol. The authors note that: "Moderate ethanol intake is associated with nutritional medicinal and cognitive benefits."
"Evidence is growing that humans are not drinking alone and that many animals ingest ethanol in their natural environment. Ethanol is ecologically relevant."
Nor do creatures using it necessarily develop a drink problem.
The world’s largest herbivore, the African elephant, is said to be partial to a tipple. Stories of inebriated jumbos impress gullible tourists, but the Bristol researchers are not impressed by such claims: "While elephants are attracted to alcohol, there is no clear evidence of inebriation in the field," they say.
The pen-tailed tree-shrew consumes nectar containing over 4% alcohol. A Berkeley University study found that nectar-feeding hummingbirds will drink a solution containing 1% alcohol, but will halve their intake if the concentration is 2%. , Some species of beetle drink beer and wasps get drunk on fermented fruits.
The researchers say: "There are several examples of butterflies and Western honeybees consuming ethanol, albeit in a contrived, rather than natural, scenario."
The supreme alcoholic of the animal kingdom is the ‘vinegar fly’. Fermented fruits, "where ethanol levels can exceed 4% and even up to 15% in anthropogenic environments", are its chosen larval habitat.
Sláinte!
