The
Sahara desert is located on the African continent covering an area of 9,200,000
square kilometres (3,600,000 sq mi). The
desert comprises much of North Africa, excluding the fertile region on the
Mediterranean Sea coast, the Atlas Mountains of the Maghreb, and the Nile
Valley in Egypt and Sudan. This desert
is home for so many animals and insects .. ..
Some
animals are really fast .. .. can
outmatch humans .. and at first thought, one would be inclined to think of
Cheetahs, deers, greyhounds and the like.
There is one yardstick in defining speed – measurement of body length
per second – that could throw open newer hitherto unthought of ones. Cataglyphis bombycina that lives in Sahara Desert is the unmatched leader. They track the Sun to always be aware of the
shortest route back to the nest. They're covered in unique hairs with a
triangular cross-section that keep their bodies cool by reflecting the Sun's
radiation, and offloading excess thermal radiation. .. .. and they move extremely fast, so they can be
in and out of the heat as quickly as possible. They spend just a few minutes
outside the nest scavenging the carcasses of fallen desert creatures before
zooming back in again.
In
case you are wondering on what these creatures are – they are ‘Saharan Silver
ants’ – to find out not just exactly how
fast, but how the ants get to such speeds, biologists from the University of
Ulm in Germany decided to film them in high speed. First, they had to locate a nest - no easy
task, since the ants spend such little time outside. But then, when that was
accomplished, the next part was much simpler. They attached an aluminium channel
to the entrance, with a feeder at the end to lure them out of the nest. "After
the ants have found the food - they love mealworms - they shuttle back and
forth in the channel and we mounted our camera to film them from the top,"
said biologist Sarah Pfeffer. In addition, the team carefully excavated a nest
and brought it back to Germany, to see how the ants moved in cooler
temperatures.
The
sand dunes of the northern Sahara are home to the fastest ants in the world,
according to researchers who clocked the insects foraging for food in the
blistering midday sun. Video footage revealed the ants galloping across the
scorching sand at speeds approaching one metre per second, the equivalent of a
house cat tearing about at 120mph. The faster the ants ran, the more they took
to the air, in gallops that brought all six legs off the ground at once. At
full pelt, the insects travelled 108 times their body length per second, the
researchers found.
So
with this speed gun – the clear winner is the Saharan silver ant (Cataglyphis
bombycina), and the speed is 855 millimetres (33.66 inches) per second. If it had taken a
while to appreciate, that's 108 times the insect's body length per second.
Even the cheetah can only manage 16 body lengths per second. Usain Bolt's top
speed is 6.2; if he could travel at Saharan silver ant speeds, his top running
speed would be around 800 kilometres per hour.
These
tiny ants are amazing. In the Sahara desert, where most creatures avoid going
out in the middle of the day to avoid blistering temperatures over 50 degrees
Celsius, the Saharan silver ant has evolved a number of adaptations to do just
that. They have longer legs than other ants, to keep their bodies farther from
the scorching sand. Their bodies produce heat shock proteins not in response to
heat, but before even leaving the nest, for maximum heat resistance. To
survive, the ants have silvery hairs that reflect the sun’s rays. But even with
this coating and other adaptations, the ants can barely survive the 60C (140F)
heat and need impressive speed and navigational skills to find food and return
to the nest before falling victim to the heat themselves.
Also
known as the European fire ant, the common red ant is also found in North
America. It can be aggressive and will bite intruders if threatened. The study
may also offer potential technical applications for humans, Pfeffer says, such
as for walking robots or vehicles that have to deal with staying upright on
loose and rapidly shifting sand. In the
Sahara, Pfeffer and her team first located several of the ants’ subterranean
nests, then set up small, aluminum channels—with floors lightly covered with
sand—on the front steps of the nests. The channels funneled the foraging ants
into a more manageable space, so the researchers could film them with
high-speed cameras from above as they raced by.
By analyzing the high-speed video, the scientists could calculate the
ants’ blistering pace. When the team compared these numbers with speeds of a
closely related, slightly larger desert ant, Cataglyphis fortis, the silver
ants were twice as fast—despite having proportionally shorter limbs.
The
ants also had remarkable coordination on the sand, seamlessly churning between
the two sets of three legs that work in unison when running. At higher speeds,
the ants would even gallop, leaving all of their feet simultaneously off the
ground at certain points. The fast strides and limited contact with the sand
may also prevent them from sliding or sinking into dunes as they look for food,
the study says.
Interesting
!
With
regards – S. Sampathkumar
21st
Oct 2019.
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