You might expect dung beetles to keep their "noses to the ground," but they are actually incredibly attuned to the sky.
A report published online on January 24 in Current Biology shows that even on the darkest of nights, African ball-rolling insects are guided by the
soft glow of the Milky Way.
While birds and humans are known to navigate by the stars, the discovery is the first convincing evidence for such abilities in insects, the researchers say.
It is also the first known example of any animal getting around by the Milky Way as opposed to the stars. "Even on clear, moonless nights, many dung beetles still
manage to orientate along straight paths," said Marie Dacke of Lund University in Sweden.
"This led us to suspect that the beetles exploit the starry sky for orientation—a feat that had, to our knowledge, never before been demonstrated in an insect."
Credit: Current Biology, Dacke et al.
Dacke and her colleagues found that dung beetles do transport their dung balls along straight paths under a starlit sky but lose the ability under overcast
In a planetarium, the beetles stayed on track equally well under a full starlit sky and one showing only the diffuse streak of the Milky Way.
That makes sense, the researchers explain, because the night sky is sprinkled with stars, but the vast majority of those stars should be too dim for the beetles'
tiny compound eyes to see.
The findings raise the possibility that other nocturnal insects might also use stars to guide them at night.
On the other hand, dung beetles are pretty special. Upon locating a suitable dung pile, the beetles shape a piece of dung into a ball and roll it away in a
straight line. That behavior guarantees them that they will not return to the dung pile, where they risk having their ball stolen by other beetles.
Researchers gave dung beetles caps to block out light. Credit: Marcus Byrne
"Dung beetles are known to use celestial compass cues such as the sun, the moon, and the pattern of polarized light formed around these light
sources to roll their balls of dung along straight paths," Dacke said.
"Celestial compass cues dominate straight-line orientation in dung beetles so
strongly that, to our knowledge, this is the only animal with a visual compass system that ignores the extra orientation precision that landmarks can offer."
Lake In France Turns Red
This year, we have encountered the color red in places where we don't expect to see it. A while back the strange appearance
of Azov Sea stunned residents who saw how the water had turned red. The red rocks in China have also puzzled scientists for a long time.
Now, a lake in Southern France has also suddenly turned red.
An Incredible Geological Phenomena
Earth is an amazing planet and our nature is full of wonders. We have previously written about incredible singing plants.
This time we would like to focus our readers' attention on another amazing geological phenomena, namely so-called growing stones.
It is difficult to image that stones can really grow, but these stones seem to be alive!
Yangtze River In China Turns Red
We have seen on a couple of occassions how lakes and seas have suddenly turned red.
In August a lake in Southern France unexpectedly changed color and shortly before that the strange appearance of
Azov Sea stunned residents who saw how the water had turned red....