There’s an interesting item in The New York Times today under the title “It’s Always Happy Hour for Several Species in Malaysian Rain Forest.” German researchers writing in the Proceedings of the National Academy of Sciences report that some rain forest mammals enjoy an alcoholic diet, by way of nectar that gets fermented in the flowers of the bertram palm. The Times reports:
The pen-tailed tree shrew, in particular, takes advantage of it. By watching the animal and analyzing fur samples, the researchers estimated that the tree shrews consumed enough alcohol that they had about a 36 percent chance of being intoxicated (by human standards). But the researchers never saw any signs of inebriation, and from an evolutionary standpoint, it makes no sense to be drunk anyway. With predators all around, Dr. Wiens said, “it’s just too risky for an animal.”
The findings, reported in The Proceedings of the National Academy of Sciences, suggest that the tree shrews and other animals have some efficient means of metabolizing the alcohol. The findings also suggest there must be benefits to having chronic low levels of alcohol in the bloodstream — otherwise the behavior would not have evolved.
The benefits may be psychological…
Well, o.k., it’s plenty good reason for me to drink a toast this evening to our newest drinking pal. And if we can’t get anybody else to drink with us, by god, the pen-tailed tree shrew will do just fine.
But here is my caveat. Plenty of animals eat plants that contain poisonous substances. Sometimes it serves an obvious benefit, as when certain insects feed on poisonous plants and then incorporate the poisons into their own defenses. And sometimes the animal just adapts to tolerate a poison so it can get the nutritional benefit of the plant, as when some lemurs adapt to eat bamboo that’s laced with cyanide.
So instead of arguing for the natural history of imbibing, the pen-tailed tree shrew might just have figured out a way to work around the alcohol. In any case, salud.