Friday, November 22, 2013

Galloping Dung Beetles

Something curious is this odd and quite unique walking pattern used just by these dung beetles.  Now the other question is whether they also still use the conventional travel method.  One supposes they do.

One also wonders just how unique this all is and just what the advantage may be.  It is likely that the heavy loading makes the two one stride too easily unbalanced in soft sand and as obviously directionally erratic.  This then forces the adoption of a  naturally balanced gait.

It is certainly odd and reminds us of the actual gait choices available to a horse.

Strange galloping dung beetle is a mystery to scientists

Scientists have discovered three species of desert dung beetle that walk like no other insect we've found, using a galloping gait similar to a running horse or a sprinting rabbit.

The vast majority of insects follow the same pattern when they walk. They lift three of their legs — the front and back leg on one side and their middle leg on the other side — move them forward and set them down, then lift the other three legs and repeat. Since rolling onto their back is usually a fairly quick death sentence, this evolved to give them the greatest support possible with six legs, while still being a fairly simple pattern their brains could follow.

Three species of dung beetle that live in the desert of southwestern Africa don't use this pattern, though. In fact, they don't even use all their legs as they walk. Check it out in this video:

Why did they evolve this peculiar way of walking? The biologists that discovered them aren't sure yet, but they do have some ideas. It might be more useful for moving straight across sand, or in carrying heavy objects while keeping their head and eyes relatively stable.

"For most dung beetles, it's always a one way trip — grab the poo, run away and never go back," said study co-author Marcus Byrne, an entomology professor at Wits University in Johannesburg, South Africa, according to PopSci. "The very marked pacing of Pachysoma's gallop might be giving it a better signal in terms of estimating the return distance from the food to its nest. When it gallops, it slips less in the soft sand."

It certainly wasn't for speed, since their gallop is actually slower than walking with all six legs. However, when you're carrying around a lump of poo that's quite possibly bigger than you are, you're probably not getting a lot of speed along your journey anyway.

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