It's not just the shaved chimps that populate our towns and cities that enjoy drinking to excess at every opportunity they get -- real chimps in the wild seem to enjoy guzzling alcoholic plant sap too.
Researchers studying chimpanzees out in Guinea have been watching them for 17 years, finding evidence that shows they enjoy sucking on ethanol that occurs in fermented palm sap, going far enough that some show "visible signs of inebriation."
The report, published by the Royal Society, explains: "Local people tap raffia palms and the sap collects in plastic containers, and chimpanzees use elementary technology -- a leafy tool -- to obtain this fermenting sap."
They also charted how they drank, with some appearing to hog the supply of booze as often occurs in the human world. They observed that: "Individuals either co-drank, with drinkers alternating dips of their leaf-sponges into the fermented palm sap, or one individual monopolized the container, while others waited their turn. Thirteen of 26 adult and immature individuals present in the Bossou community between 1995 and 2012 (excluding infants) were never seen ingesting palm sap."
The results appear to support the "drunken monkey" theory of evolution, which suggests that boozing is key to all manner of positive aspects of the development of life, by stimulating appetite and helping take on extra calories. [BBC]