Bees and Hummingbirds Are Drinking Alcohol—And They’re Fine With It
Bees and hummingbirds don’t just sip nectar. They also consume tiny amounts of alcohol all day long. Why? Many flowers naturally contain ethanol. Yeast ferments the sugars, creating small quantities of alcohol. UC Berkeley biologists conducted the first large survey of alcohol in floral nectar. They tested 29 plant species. Remarkably, 26 had at least one sample with detectable ethanol.
How Much Do They Actually Drink?
The levels sound tiny, often just trace amounts. However, pollinators rely heavily on nectar. Hummingbirds, for example, drink up to 150% of their body weight each day. As a result, their alcohol intake adds up. Researchers estimate an Anna’s hummingbird consumes about 0.2 grams of ethanol per kilogram of body weight daily. That is comparable to a human having one standard drink.
Built for Tolerance, Not Intoxication
Despite this steady intake, bees and birds show no signs of getting drunk. They metabolize alcohol extremely quickly. “Hummingbirds are like little furnaces,” explains doctoral student Aleksey Maro. “They burn through everything really quick”. In fact, experiments show that hummingbirds will happily drink sugar water with up to 1% alcohol. But they start avoiding it when concentrations rise above that level.
Evolutionary Clues in Their Feathers
Earlier studies found that hummingbird feathers contain a byproduct of alcohol metabolism. This proves they process ethanol similarly to mammals. The findings suggest a broader evolutionary story. Many animals—including our own ancestors—may have developed tolerance to dietary alcohol over time. As professor Robert Dudley notes, this chronic daily exposure likely shaped physiological adaptations. “The comparative biology of ethanol ingestion deserves further study.”
