To the casual observer, echidnas seem to just
waddle around and look weird, but new research
reveals that these busy evolutionary throwbacks
keep Australia's soil healthy.
We already knew they were diggers, as echidnas
--or spinney anteaters -- depend on a diet
of ants, termites, worms and grubs.
They spend a lot of time plowing the earth
and overturning rocks in search of their prey,
but scientists knew relatively little about
their lives beyond these generalities.
In a recent study published in the Journal
of Experimental Biology, a team of Australian
biologists unlocked the secrets of the life
echidna.
They strapped GPS and accelerometer-equipped
trackers to 12 short-beaked echidnas and let
them run wild.
The resulting data filled in a number of details
surrounding their
bug-sucking, dirt-digging lifestyles.
They learned that echidnas boast shorter stride
lengths and frequencies than other animals
their size, and that their daily activity
level depends greatly on ambient air temperatures
-- with spring standing as their busiest season.
This makes perfect sense because echidnas
have lowest body temperature of any mammal
-- 89°F or 32°C. They also lack the temperature
control of most other mammals, causing their
body temperature to fluctuate by several degrees
in the course of a day.
As such, they live a little more like cold-blooded
reptiles than the rest of their warm-blooded
kin and limit their activity during the heat
of the summer.
But the study's coolest finding was that Echidnas
spend an average of 12 percent of their time
digging -- and in the process move a colossal
amount of soil.
One of the researchers predicts that the dozen
specimens tracked in their study collectively
move an Olympic-sized swimming pool's worth
of dirt every year.
In this, they aerate and mix the Australian
soil.
And since they're one of just a few surviving
native Australian burrowers, they're not just
a biological oddity -- they're a true keystone
species.
Though, to be fair, echidnas will always stand
out as a little bit odd.
Only four species remain, spread across the
long-isolated ecosystems of Australia, Tasmania
and New Guinea.
Like the platypus, they're egg-laying monotremes
-- and they also seem to exemplify a chimerical
blend of anatomical features: the spines of
a porcupine, the toothless beak of a bird
and the pouch of a marsupial.
But if that wasn't enough, the wonderful and
weird echidna also live up to 50 years in
captivity thanks to their slow metabolisms.
Females lactate through milk patches in their
pouches, while males are somewhat famous for
their four-headed penises.
The males are also known to sneak into burrows
to mate with hibernating females, which is
a departure from the so-called "mating trains,"
in which a line of male suitors simply follows
the female around for up to 6 weeks.
And if that still wasn’t enough, they also
play host to the largest fleas on the planet,
which are 0.15 inches or 4 mm in length.
Echidnas are cute, sure, but it also makes
sense that we named them after the Greek Mother
of Monsters.
The natural world is weird -- and if you want
to learn more about it, be sure to check out
NOW.howstuffworks.com each and every day.
