Tree shrews get tipsy from nature-made fermented nectar

Slender treeshrews drink far more than most humans ever could for their body weight, and have been doing so for up to 55 million years.

"They show no obvious signs of drunkenness when observed from only 9.8 feet away away," lead author Frank Wiens told Discovery News. "However we do not rule out psychopharmacological effects induced by alcohol."

Wiens and his team made the discovery, outlined in the latest Proceedings of the National Academy of Sciences, after first detecting a "strong alcoholic smell reminiscent of a brewery" from flowers of the bertam palm in the West Malaysian rainforest Segari Melintang Forest Reserve in the State of Parak. Nectar from this plant frequently frothed up and out of the palm's long, tubular flowers.

The researchers conducted video surveillance of visitors to the plant and determined that many species bellied up to the bar-like scene, particularly at night, when the number of visits more than doubled. Nocturnal imbibers included the gray tree rat, the Malayan wood rat, the chestnut rat, the slow loris and the pentailed treeshrew.

The natural brew contains up to 3.8 percent alcohol, which is very close to the alcohol content of most human-manufactured beers. Given variations in alcohol content and amounts consumed, Wiens and his team say the clawed, big-eyed treeshrews would have a 36 percent chance of being drunk, by human standards, on any given night.

In the future, Wiens and his team hope additional studies on pentailed treeshrews and their favorite food might help to explain how alcohol consumption emerged in humans and why certain groups possess different levels of tolerance.