Elephant Poo Air Conditioning
Posted by Richard Conniff on October 23, 2012
Apparently, elephant excrement is the next best thing to a Frigidaire window unit, if you are a dung beetle, according to researchers studying how the beetles roll balls of dung across the desert to their nest, in South Africa:
“The beetles climb on top of their moist balls whenever their front legs and heads overheat,” said Prof. Marcus Byrne from Wits University. “We stumbled upon this behaviour by accident while watching for an ‘orientation dance’ which the beetles perform on top of their balls to work out where they’re going. We noticed that they climbed their balls much more often in the heat of the midday sun.”
Further experiments showed that this midday phenomenon only held true when the beetles were crossing hot ground. In fact, beetles on hot soil climb their balls seven times as often as those on cooler ground.
To show that it was the beetles’ hot legs that made them climb the ball, the researchers applied some cool (as in temperature) silicone boots to their front legs as alternative protection from the heat. “To our great surprise, this actually worked, and beetles with boots on climbed their balls less often,” said Dr Jochen Smolka from Lund University, who collaborated on the research.
You have to love any study that involves putting booties on dung beetles. And one last bit of ickiness:
Once on top of a ball at midday, the beetles were often seen “wiping their faces,” a preening behavior that the researchers suspect spreads regurgitated liquid onto their legs and head to cool them down further. That’s something the insects never do at other times of day.
Source: Jochen Smolka, Emily Baird, Marcus J. Byrne, Basil el Jundi, Eric J. Warrant, Marie Dacke. Dung beetles use their dung ball as a mobile thermal refuge. Current Biology, 2012; 22 (20): R863 DOI: 10.1016/j.cub.2012.08.057