Natures wonders: Dung beetle navigation: (Introduction)

by David Turell , Tuesday, August 25, 2015, 18:45 (3376 days ago) @ David Turell

Using sun, moon and polarized light:-http://phys.org/news/2015-08-dung-beetles-celestial-cues-species.html-"Dung beetles quite often are the butt of jokes, collecting as they do, pieces of excrement from other animals, forming it into a ball and then rolling it across the ground to a private destination. But, they have pretty sophisticated navigation skills—they can roll their ball of dung in a straight line, despite uneven terrain, ending up in a spot they pick some distance from where the dung was found. Prior research has shown that the beetles use celestial cues to help keep themselves oriented, but just how they do that has been a mystery—until now.-"In this new effort, the researchers studied specimens from two species of dung beetles, diurnal (those that operate mainly during the day) and nocturnal. They did so by collecting specimens, putting them in an artificial environment where celestial cues could be modified and then watching how the beetles performed—that allowed for identifying which celestial cues were at play. They found that as expected, diurnal beetles depended on the sun's location during the day, and on the moon's location at night. But the nocturnal beetles depended on polarized light from the moon at night and the sun during the day.-"Next, the research group took a closer look by making electrophysiological recordings of the beetles' brain cells as they were exposed to sun and moon light. That showed that the nocturnal species had neurons that would switch between responding to polarized light and light from the sun, whereas the neurons in the brains of the diurnal species switched between responding to light from the sun or the moon.-"The team also theorized that the nocturnal species' navigate at night when there is no polarized light from the moon available, by using light from the Milky Way."