“Alcohol Self-Administration by Elephants”, Ronald K. Siegel, Mark Brodie1984-07-01 (alcoholism, animal psych)⁠:

The anecdotal and historical literature describing intoxication in elephants from fermented fruit or alcoholic beverages is reviewed. Seven African elephants readily self-administered 7% unflavored alcohol solutions; the results included separation from herd groupings and changes in the frequency and/or duration of several behaviors as scored according to a quantitative observational system. Alcohol decreased feeding, drinking, bathing, and exploration for most animals. Inappropriate behaviors such as lethargy and ataxia increased for all elephants. Results are discussed in terms of stress-induced drinking and intoxication.

…The first elephant was brought to America in 1796 and was billed as“the most respectable animal in the world” even though it drank 30 bottles of port a day, drawing the corks with its trunk (Winfrey1980, pg64). And elephant trainers and handlers regularly employ beer and other beverage alcohol as positive reinforcers for their animals (eg. Lewis & Fish1978).

This apparent preference for alcohol has produced dramatic consequences. For example, in 1974 a herd of 150 elephants broke into an illegal still and drank copious quantities of “moonshine” liquor. Intoxicated, they rampaged across West Bengal, killing 5 people, injuring 12, demolishing seven concrete buildings, and trampling 20 village huts (San Francisco Chronicle 1974). In Africa, elephants have been known to cause wide-spread destruction of property in their search for and intoxication from beverage alcohol.

…It was found that 7% solutions were the highest concentrations readily and totally self-administered when water was also available ad lib. Interestingly, the 7% concentration is equivalent to the alcohol concentration found in the fermented grain eaten by elephants in Africa. When ethanol was flavored with fruit extracts, the elephants self-administered 10% concentrations, but no higher.