To escape the inevitable summer heat, Bogong moths migrate every spring from Queensland, New South Wales and Victoria to the meadows of the Australian Alps. Once their journey is complete, they congregate in caves and go dormant for summer, similar to hibernation. Upon Autumn’s arrival, these insects return to their birthplaces, mate, lay eggs, and die. The eggs turn into caterpillars that develop underground throughout the winter, and the cycle continues indefinitely. This journey has long been a mystery. How do these insects travel to a place they have never been and back, while covering several hundred miles in just one night for weeks? Scientists have found that a magnetic sense is helping these remarkable creatures. A paper published in Current Biology reports scientists used an outdoor flight simulator to test their hypothesis. They focused on testing the Bogong’s reaction to moving visual cues and the Earth’s magnetic fields. While it is understood that other animal species use magnetic fields to navigate, scientists suggest this is the first evidence of this phenomenon being evident in insects. Other than Monarch butterflies, Bogong moths are the only insects to have such a complex but directed migration pattern. “They have this sort of amazing ability that belies their appearance,” said Eric Warrant, a biologist at the University of Lund in Sweden and the principal investigator of the study. “It’s as if the Bogong moth is the dreary-colored, nocturnal cousin of the Monarch butterfly.” The Monarch is known to fly during the day depending upon the rising and setting sun. The moths, on the other hand, fly only under dim stars and a fleeting moon, initially leading scientists to believe that the moths relied on celestial help for their navigation. Study and Findings Researchers collected specimens during a migration. To confirm their findings, they tethered them to a metal rod in the center of a plastic drum and recorded their flight patterns in response to a moving felt cutout of a mountain and a synthesized magnetic field, similar to Earth’s. Most flew toward the cutout but became disoriented when the magnet field changed. This behavior led scientists to believe the moths integrate visual cues and magnetic signals, checking in every now and then to make sure they align. This would be comparable to a hiker that uses a compass and landmarks, such as large trees or mountaintops, to keep his bearings. To further their research, scientists plan to study the moth’s responses to projections of the Milky Way, how their brains’ navigation center responds to magnetic fields, and how genetics might offer the moths access to some kind of inherited map of their migration route. We will be sure to keep an eye out for these results and other ways magnetic fields are explaining the world around us, including how fish also have a magnetic sense! For similar articles to fulfill your curiosity, visit our blog section.