Monday, January 28, 2013

A Dung Beetle: The smallest astronomer

Humans have a love for the night sky. Even early humans must have looked up in wonder - it's no surprise that astronomy is the oldest of all the natural sciences. Not only do we love stargazing, but ships have crossed oceans and slaves in America found freedom by looking to the stars. As it turns out we aren't alone in our love for the stars.

The life of a dung beetle (Scarabaeus zambesianus) is simple: Find a pile of dung, roll it into a ball, and run away with it. The beetle needs to get away quickly, so a straight line is its best bet. During the day it can use the sun as a reference point and at night it has the moon, but what if the moon isn't visible? They don't use any local landmarks to orient themselves, so how do they find their way? New research shows that when the moon isn't visible the dung beetle can use the Milky Way as a reference frame

To test the beetles the researchers used a planetarium, changing which stars were visible. Without the Milky Way the beetles were unable to walk in a straight line. So, even though the beetle's eyes are not sophisticated enough to see individual stars, the bright streaks of the Milky Way are enough to guide it. It makes me wonder if the beetle enjoys looking at the stars or just sees a map when it looks up.