Pollinators Drink Alcohol from Flowers Every Day
Scientists at the University of California, Berkeley have discovered that bees and hummingbirds regularly consume alcohol when they feed on flower nectar. This alcohol, called ethanol, forms naturally when yeast breaks down sugars in the nectar through a process called fermentation.
The research team tested 29 different plant species and found ethanol in at least one nectar sample from 26 of them. While most samples contained only tiny amounts, one reached about 0.056% ethanol by weight. These levels may seem small, but they add up because nectar is the main food source for many pollinator species.
Hummingbirds drink a huge amount of nectar daily, between 50% and 150% of their body weight. Based on this feeding behavior, researchers calculated that an Anna's hummingbird consumes about 0.2 grams of ethanol per kilogram of body weight each day. This is roughly equivalent to a human drinking one alcoholic beverage.
However, pollinators do not appear drunk because they consume the alcohol gradually throughout the day and burn through it quickly as energy. Experiments showed that hummingbirds will drink sugar water containing up to 1% alcohol, but they avoid higher concentrations. Scientists also found that hummingbird feathers contain a chemical byproduct that proves these birds metabolize alcohol similarly to mammals.
The researchers believe that many animals, including human ancestors, may have evolved tolerance for dietary alcohol over time. The ethanol might affect pollinator behavior in subtle ways beyond intoxication, similar to how nectar compounds like caffeine and nicotine influence animals. Further research is needed to understand these potential effects.