Yes, birds can become intoxicated from eating fermented fruit, a natural phenomenon sometimes referred to as avian intoxication. This occurrence is a biological reality that takes place when wild fruits linger on branches or fall to the ground and begin to rot. The result is a temporary but sometimes dangerous state of impairment for the birds that consume them.
How Berries Become Alcoholic
The transformation of a sweet berry into an alcoholic one is a chemical process called fermentation. Yeast, naturally present on the skin of many fruits, consumes the fruit’s sugars once the berry is overripe or damaged. As the yeast metabolizes the sugar, it produces ethanol—the type of alcohol found in beverages—and carbon dioxide as byproducts.
Cold weather intensifies this process. Freezing temperatures break down the fruit’s cell walls, releasing and concentrating the internal sugars. When the temperature warms up, the concentrated sugar solution accelerates fermentation. This sometimes results in a more potent alcohol content. Because birds have a very fast metabolism, even a small amount of this naturally occurring ethanol can affect their bodies rapidly.
Identifying Intoxicated Birds
The effects of consuming fermented fruit mimic human intoxication, providing clear signs that a bird is under the influence. Intoxicated birds often display a loss of coordination, making flight erratic and causing them to crash into objects like windows and cars. They may also stumble clumsily on the ground, perch with difficulty, or exhibit unusual lethargy and confusion.
The species most frequently observed in this condition are frugivores, whose diet relies heavily on fruit. Cedar Waxwings and Bohemian Waxwings are commonly involved due to their tendency to gorge on berries in large quantities. Other species, including European Starlings and American Robins, are also susceptible.
The fruits most likely to cause this problem persist well into the cold season, including berries from:
- Rowan
- Juniper
- Crabapple
- Mountain ash trees
Protecting Intoxicated Wildlife
Intoxication poses significant risks to a bird’s survival, as the impairment prevents them from avoiding common dangers. The inability to fly straight or maintain balance makes them vulnerable to fatal collisions with hard surfaces. Disoriented birds are also less capable of evading predators or finding safe shelter, especially during cold weather.
If a bird appears intoxicated but is in a safe location, leaving it alone to recover is the best approach. If the bird is found in a precarious spot, such as near traffic or a house pet, careful intervention is necessary. Gently place the bird in a secure, dark, and well-ventilated container, like a cardboard box, which acts as a makeshift “drunk tank.”
This secure environment allows the bird to metabolize the alcohol and “sleep it off” safely, protected from external threats. Do not attempt to feed the bird or force water into its beak, as this can cause aspiration. If the bird does not recover within a few hours, or if it appears injured, contact a local licensed wildlife rehabilitator for professional guidance.