Should bats fly when they have been drinking?
That's the question a team of researchers set out to answer recently by studying the fruit-eating and nectar-drinking bats of Belize.
University of Regina researcher Yvonne Dzal was part of the team.
Dzal joined a research group from the University of Western Ontario and travelled to Belize to study bats, particularly bats that eat fruit, which may contain a certain percentage of ethanol, depending on how ripe it is.
To compare their performances, the researchers fed some bats punch spiked with ethanol and had them fly through an obstacle course, along with bats that had not been drinking.
"Well, we predicted that they were going to fall all over the place kind of naturally, like we all do from time to time when we have too much to drink," Dzal said. "We gave them quite a hefty amount, the bats that were drinking."
"However the sober bats and drunk bats seemed to be quite on par [in terms of their performance]."
The bats given alcohol tested at three times higher than the legal driving limit for humans, but they acted stone cold sober, she said.
Not all bats are alike, she said. Egyptian bats for example showed the opposite effect. They got drunk.
"Fleshy fruits found in the neotropics may ferment faster and have higher ethanol concentrations than those in Mediterranean habitats, possibly reflecting differences in humidity, fruit abundance, and prevailing temperatures," the team reported.
"Thus foraging neotropical fruit- and nectar-feeding bats may naturally be exposed more often to comparatively high levels of ethanol compared to those in Mediterranean areas, and therefore may have higher tolerances for ethanol," it said.