For African beetles, dung balls double as 'air conditioning units'
Some African dung beetles roll their feasts of dung away to avoid the hordes of other hungry bugs at the pile. But now researchers who report their findings in the October 23 issue of Current Biology, a Cell Press publication, have discovered that the beetles also use the balls in another, rather clever way: The moist balls keep the bugs cool even as they push a weight up to 50 times heavier than their own bodies across the scorching sand. "Like an air conditioning unit, the moist ball is cooled by evaporative cooling," said Jochen Smolka of Lund University. "The beetles climb their cool balls whenever their front legs and their head overheat from pushing this huge dung ball across the hot South African sand."
The discovery marks the first example of an insect using a mobile thermal refuge in this way. It is also a demonstration of the remarkably sophisticated strategies that insects and other cold-blooded creatures employ to maintain their body temperatures.
Smolka's team stumbled upon this unusual behavior completely by accident. In fact, dung beetles also climb atop their dung balls to perform an "orientation dance" that the insects use to work out where they are going. As they watched for the dancing, the researchers began to notice that the beetles climbed their balls of dung 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, the researchers report, beetles on hot soil climb their balls seven times as often as those on cooler ground.
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.
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," Smolka said.
The findings are yet another reminder of the many creative solutions found in nature, Smolka added. "Evolution has an astonishing ability to make use of existing structures for new purposes -- in this case using a food resource for thermoregulation."
Source: Cell Press
- Dung beetle dance provides crucial orientation cuesSat, 21 Jan 2012, 0:33:43 EST
- Exotic manure is sure to lure the dung connoisseurWed, 11 Apr 2012, 18:02:43 EDT
- Fossilized dung balls reveal secret ecology of lost worldWed, 15 Jul 2009, 19:35:35 EDT
- Glaciations may have larger influence on biodiversity tan current climateWed, 8 Jun 2011, 10:02:43 EDT
- Glaciations may have larger influence on biodiversity than current climateTue, 7 Jun 2011, 14:02:06 EDT
- Beetle Air Conditioning, Silicon Boots, And A Ball Of Dungfrom Scientific BloggingThu, 25 Oct 2012, 10:40:34 EDT
- Beetles dance on poop balls to keep coolfrom MSNBC: ScienceMon, 22 Oct 2012, 17:01:08 EDT
- That's Hot! Beetles Dance on Poop Balls to Keep Coolfrom Live ScienceMon, 22 Oct 2012, 16:00:52 EDT
- In Images: Beetles Dance on Poop Balls to Keep Coolfrom Live ScienceMon, 22 Oct 2012, 16:00:38 EDT
- Soil Hot, Poop Cool - Dung Beetle Dance | Videofrom Live ScienceMon, 22 Oct 2012, 15:31:04 EDT
- For African beetles, dung balls double as 'air conditioning units'from Science DailyMon, 22 Oct 2012, 14:31:12 EDT
- Beetles use dung balls to stay coolfrom Science DailyMon, 22 Oct 2012, 14:31:11 EDT
- Beetles use dung balls to stay coolfrom PhysorgMon, 22 Oct 2012, 13:02:01 EDT
Latest Science NewsletterGet the latest and most popular science news articles of the week in your Inbox! It's free!
Check out our next project, Biology.Net
From other science news sites
Popular science news articles
- Mysteries of Earth's radiation belts uncovered by NASA twin spacecraft
- Fledgling supernova remnant reveals neutron star's secrets
- Sea level rise and shoreline changes are lead influences on floods from tropical cyclones
- CU-Boulder-led team finds first evidence of primates regularly sleeping in caves
- New fossil species found in Mozambique reveals new data on ancient mammal relatives
- Stanford study suggests why, in some species, mere presence of males shortens females' lifespan
- 'Spooky action' builds a wormhole between 'entangled' quantum particles
- Fruit flies with better sex lives live longer
- The mystery of neutron stars heats up
- New report calls for attention to abrupt impacts from climate change