ALCOHOL IS A NECESSARY EVIL FOR BATS

Abstract

While some species may find the ingestion of alcohol relatively pleasant,ethanol is still a potent toxin. But for species that rely on fruit for sustenance, it is a necessary evil. According to Francisco Sánchez and colleagues from Ben-Gurion University of the Negev, the toxic effects of alcohol can be minimised if consumed with food containing natural sugars such as fructose, sucrose and glucose. As these sugars occur naturally in fruits,Sánchez and his colleagues decided to test how they affected the rate of alcohol elimination in the bat's breath. Giving Egyptian fruit bats food containing a shot of ethanol mixed with one of the three sugars, the team monitored the bat's breath alcohol content and found that the ethanol levels dropped fastest when it was ingested with fructose; the bats removed alcohol from their systems fastest when mixed with fructose(p. 1475).The team also decided to investigate how the bats' perception of the foods'value changed when alcohol was added by measuring the amount of food left after a night's foraging. As the alcohol level was increased, the bats left less food containing sucrose than food containing the other two sugars; the value of sucrose consumed in the presence of alcohol increased more than the two other sugars' values, and the value of fructose increased more than that of glucose. So both fructose and sucrose are `complementary' to ethanol,contributing more to the bat's fitness when consumed together than when consumed individually.