Photo: Emily Baird via LiveScience
What happens when you take a dung beetle into a planetarium? You figure out it knows a lot more about our galaxy than you’d think.
TEDx speaker Marcus Byrne is one of the several scientists behind a new study — published this week in Current Biology — that has revealed the dung beetle to be the very first animal proven to use the entire galaxy for direction, rather than individual stars or constellations. His TEDxWitsUniversity talk, "The dance of the dung beetle," featured on TED.com in December, explained some of his earlier research on the creatures and their directional skills.
In his talk, Byrne explains how dung beetles use the sun, the moon, and polarized light as guidance while rolling scavenged dung back to their nests. But of course, research didn’t stop there. “We were sitting out in Vryburg (conducting experiments) and the Milky Way was this massive light source. We thought they have to be able to use this – they just have to!” he said in a press release about the study.
Soon, the team realized that at night, beetles have no problem directing dung balls when the sky is clear, even if no moon is visible, but come across major issues whenever it is overcast. “This led us to suspect that the beetles exploit the starry sky for orientation — a feat that had, to our knowledge, never before been demonstrated in an insect,” said fellow researcher Marie Dacke.
After many observations outdoors, Byrne and the other researchers brought their research inside the Wits Planetarium in South Africa. An article in Cosmic Lab from NBC News explains the tests:
The planetarium was programmed to show the night sky with the Milky Way, or the Milky Way without the brightest stars in the sky, or the brightest stars without the Milky Way, or just the diffuse glow of the Milky Way with no stars at all.
The bottom line was clear: Those bugs could keep track of how the fuzzy streak of the Milky Way was oriented in the sky, to make sure they rolled their balls of dung in a suitably straight line.
However, “not all light sources are equally useful landmarks for a dung beetle,” Wits University reports. “The scientists suspect the beetles have a hierarchy of preference when it comes to available light sources. So if the moon and the Milky Way are visible at the same time, the beetles probably use one rather than the other.”
Still, a dung beetle that knows the Milky Way is a dung beetle we’d like to know. To learn more about these captivating galaxy-gazers, watch Byrne’s TEDx Talk, or check out TED's playlist of “7 talks that contain fascinating facts about beetles.”