Tiger beetle uses wind power to roll like Sonic the Hedgehog
Tiger beetle larvae distort their bodies into the shape of a wheel and harness the wind to roll across the sand.
Tue, Mar 29, 2011 at 02:27 AM
Researchers at Georgia Southern University have discovered a new form of wind-powered animal locomotion so bizarre that it looks like something out of a video game, reports PhysOrg.com.
The oddball behavior was first observed while former GSU biology graduate student Sarah Zukoff took a short vacation along the seashore of Georgia's Cumberland Island. The beach there is home to a common species of tiger beetle, Cicindela dorsalis, which look worm-like in their larval stage. Since they are a well-studied species, Zukoff wasn't expecting to make any discoveries. But what she saw there was unlike anything she had ever seen before — larval tiger beetles, shaped like wheels, rolling across the sand.
Wheeled locomotion, which involves an animal distorting its body into a rolling wheel, has only been reported for a few species worldwide, and until now no one had seen the behavior performed by larval tiger beetles. But what made the tiger beetle's wheeled locomotion even more unique was how it propelled itself. Since a consistent sea breeze blows off the Cumberland Island seashore, the beetle's wheelies were powered by the wind. They could even ride the wind to roll uphill.
According to Alan Harvey, co-author of the study, this is the first instance ever reported of wind-powered wheel locomotion.
"At first we thought our larvae were just wildly thrashing around until they happened to catch the breeze. But our slow-motion videos showed that they were actually making carefully timed leaps that became these beautiful aerial somersaults, which seemed to let them orient to the breeze and then 'hit the ground rolling.' We almost couldn’t believe our eyes," he said.
In fact, the behavior is so strange that the easiest comparison might not be to another animal at all, but rather to the famous video game character, Sonic the Hedgehog.
"That we could find such an astounding suite of behaviors in such a well-studied animal is very rare," Harvey added.
The two researchers speculated that the wheeling behavior might have evolved as an escape mechanism from predatory wasps that feed on the larvae. They also suggested that recent declines in the tiger beetle population might be due to human impact, which has deteriorated the flat, hard surface the beetles require for efficient wheeling.
For more information, and to see the incredible Sonic-like beetles performing their wheelies, check out this video produced by the research team at Georgia Southern University: