“Drunken” animals may be more common

Wild nature behaves like drunk people after meals fermented fruits generally considered a rare occurrence and not well documented in the academic literature. However, one group of environmentalists disputes the assumption that animals do not eat fruits rich in ethanol and nectars that often. They argue that because ethanol-laden fruits are present in nearly every ecosystem on the planet, these fruits are likely to be consumed more regularly by animals that eat nectar and fruit. The argument is detailed in a article published Oct. 30 in Cell Press Trends in ecology and evolution.

“We’re moving away from this anthropocentric view that ethanol is just something that people use,” study co-author Kimberly Hawkings and a behavioral ecologist at the University of Exeter in the UK. the statement says. “It’s much more abundant in nature than we previously thought, and most animals that eat sugary fruit will be exposed to some amount of ethanol.”

(Related: Different types of alcohol can cause you different emotions.)

What is ethanol?

in fruit ethanol is a natural substance– the result of fermentation of fruit sugars by yeast. This is the first became common about 100 million years agowhen flowering plants began to produce sugary nectar that yeast could ferment. Ethanol is now present almost every ecosystembut its concentration is higher and is observed all year round in low latitudes and humid tropical zones.

Usually, naturally fermented fruits reach only 1-2 percent alcohol by volume (ABV). However, concentrations of up to 10.2 percent ABV have been found in overripe palm fruit in Panama. For comparison, the majority alcoholic beverages consumed by a person ranging from 3 percent ABV (light beer) to 50 percent ABV (distilled alcohol).

Whereas animals already have it genes required for ethanol degradation before yeast began to produce it, there is some evidence that evolution fine-tuned the ability of mammals and birds to eat fruit and nectar. Primates and small mammals called shrews have adapted to efficient ethanol metabolism particularly well. Spider monkeys are fed on fermented yellow mombin fruit, with fruit ethanol levels ranging from one to 2.5 percent. Wild chimpanzees repeated consumption of fermented palm was also observed. Elephants, baboons and other wild animals too probably getting drunk on marula fruit in Botswana. However, in these cases, ethanol content was not detected in fruits, nor in animals.

“It’s not ecologically beneficial to be drunk when you’re climbing trees or surrounded by predators at night – that’s a recipe for your genes not being passed on,” said study co-author and the College of Central Florida. molecular ecologist Matthew Carrigan the statement says. “It’s the opposite of people who want to be high but don’t really want the calories—from a nonhuman perspective, animals want the calories but not the high.”

Potential benefits

in new paperthe team analyzed the available scientific literature to understand the prevalence and role of ethanol in the natural world, and what the evolutionary benefits to animals might be.

They found that it is still unclear whether animals intentionally consume ethanol for the sake of it, and more research is needed to understand how it affects animal physiology and evolution.

However, they found that ethanol consumption can have several advantages for wild animals. It is a source of calories, and odors produced during fermentation can direct animals to food sources. The team does not believe that animals can detect ethanol in fruit by smell alone.

(Related: Why fruit bats can eat tons of sugar without getting diabetes.)

Ethanol may also have some medicinal benefits. For example, fruit flies deliberately lay their eggs substances containing ethanol. This protects the eggs from parasites. Fruit fly larvae also increase ethanol consumption when parasitized by wasps.

“On the cognitive side, it has been suggested that ethanol may trigger the endorphin and dopamine system, leading to a feeling of relaxation that may have social benefits,” study co-author and University of Exeter behavioral ecologist Anna Bowland said. the statement says. “To test this, we really need to know if ethanol causes a physiological response in nature.”

According to the teamthere are still several unanswered questions regarding the significance of ethanol consumption for wildlife. In future studies, they plan to examine the behavioral and social consequences of ethanol consumption in primates and take a closer look at the enzymes involved in alcohol metabolism.