Busting bat myths
Tim the Yowie Man
Tim the Yowie Man
Many years ago, when I was in school, I had to complete an assignment on bats. Among the various ‘facts’ I found in some obscure reference book was that ‘bats fly left when leaving a cave’.
Somehow, I jagged an A. In retrospect, my science teacher, Mr Brown, ought to have failed me because – in today’s parlance – it was fake news.
“It’s a complete myth,” says Terry Reardon, life member of the Australasian Bat Society. And Terry should know – he’s been studying bats for more than half a century. “Which way bats leave a cave depends on a number of factors, including the topography around the cave and the direction of food and water sources,” he says.
Terry has spent the past four years closely observing southern bent-wing bats at Naracoorte Caves in South Australia. “They just fly out in different directions, some north, some south, and at no particular angle,” he says. “My observations at cave and mine entrances suggest no universal exit direction.”
And before you ask: no, the bats don’t return to the cave from a certain direction. “They come in from every direction,” Terry says. He often observes them returning at dawn from the comfort of his swag.
So, what about other caves?
NSW National Parks and Wildlife Service ecologist Doug Mills has been studying eastern bent-wing bats at Wee Jasper for almost 20 years. He admits he gets asked the question often, but says “there’s no scientific basis to the claim they turn left”.
“On their nightly forages for food and water the bats usually exit to one side of the cave, but that’s because it’s just easier for them to exit on that side as it means they can fly downhill. If they were to turn the other way, it’d be a bit harder for them to get the elevation they need to fly off,” he says.
It begs the question: do left and right actually have meanings in a cave context?
“For caves that have vertical entrances, the direction of flight is dependent on where the viewer is,” Terry says. “Only for caves with horizontal entrances do left and right have meaning.”
An equally intriguing conundrum is which direction bats circle while preparing to exit a cave.
At Naracoorte Caves, Terry has recorded southern bent-wing bats circling en masse in a clockwise direction before embarking on their nightly flyout from a maternity cave.
“After the bats circle below the entrance, they fly out of the cave and disperse in multiple directions,” Terry says. “We don’t have cameras in other caves, so we aren’t sure if this is just in this cave or if it’s a more general habit.”
What it does show is how much more we still have to learn about these fascinating creatures. One thing is for sure, though: the myth that bats fly ‘left’ out of a cave is most definitely busted.
Sorry, Mr Brown.
