Frogs and toads, cold-blooded herptiles (amphibians and reptiles)
can be found on every continent except Antarctica. The name
originates from ancient Greek, roughly translating to "loathsome yucky thing which crawls on its belly." They
have been around since the Jurassic period, sharing the world
with the likes of Tyrannosaurus rex, and were the first creatures
on this planet to develop vocal chords.
"Ribbit," or as we say in Japan "kerokero," were the first
words ever spoken by a living creature.
There are around 2,000 species, ranging in size from the African bull frog (a ten-pound giant with a mouth big enough to swallow a cat) to the tiny arrow frogs no bigger than a fingernail. Some species hibernate under icy ponds to pass the winter; others go to sleep underground, sometimes for years, to escape a desert drought.
They fill the summer nights with musical choruses, and where ever there is water, frogs can be found, singing about sex. A male frog with a strong voice will be irresistible to the lady frogs - a bit like being a famous pop star.
In many human cultures frogs and toads are believed to bring
good luck by foretelling the onset of rain. They can often
sense when the year's first downpour is coming and will appear
in great numbers where ponds are likely to form.
It is because of this sudden, almost magical emergence, coinciding with a change in the weather, which has led some of us to believe that frogs arrive in the clouds and fall from the skies. Sometimes this really happens, such as in Mexico when small tornado passed over a pond full of croaking frogs. The unsuspecting creatures were sucked up and later dumped on a small village, causing a bout of religious panic amongst the residents.
There are also darker legends, tales of black magic and potions
and spells. No witch's house was complete without a toad lurking in the corner next to a big bubbling cauldron; it's
an integral ingredient in all evil brews.
Medieval records in England speak of toads facing trial for witchcraft, and then being burned at the stake. But these reputed magical powers are, in fact, not too far from the truth. Nearly all amphibians produce skin toxins. These powerful alkaloid compounds can sometimes, if ingested, result in paralysis and death. They also cause visual and auditory hallucinations (similar to magic mushrooms). Witches and wizards of old understood how to use these substances long before the world of modern science discovered them.
The frogs themselves use these poisons as a defense against
hungry predators, a very clever and effective method of protection,
and one which has been taken to extremes by the tiny South
American poison arrow frogs. Just one microgram (an amount
smaller than a grain of sugar) is enough to kill a human
being, and simply picking one up in your hands could prove
fatal. These brightly colored jewels of the rainforest are
traditionally used by Indian tribes as military hardware.
Hunting darts and war weapons are carefully rubbed upon the
frog's skin so that enemies and prey can be killed instantly
with nothing more complex than a tiny wooden dart.
But although they are deadly, medical scientists have been investigating the properties of the chemical compounds and as a result, drugs are being developed that will alleviate chronic and long-term pain in human patients.
There is also hope for future breakthroughs regarding the
treatment and prevention of Alzheimer's disease and strokes.
Pharmaceutical companies are confident that drugs will be
developed that will eventually bring benefits to over forty
million people worldwide.
But one serious obstacle faces the continued research and development of these drugs. The frogs themselves are becoming extinct.
Across the globe, hundreds of species are becoming infected with a deadly fungus, and specialists worry that it may eventually wipe out every single amphibian on this planet.
The causes are yet uncertain, but scientists speculate that
manmade environmental change is to blame. A frog's skin is a very sensitive organ; they breathe through it and they drink through it. The slightest change in their environment can damage this skin, increasing the animal's
susceptibility to infection.
Herpetologists (those who study amphibians and reptiles) have described frogs as early bio-indicators. In other words, due to their extreme sensitivity, their health directly reflects that of the quality of the environment they live in.
Declining amphibian populations are a concern because they indicate general environmental decay and contamination, with serious implications on the future health of other animals - including human beings.
Efforts are being made to find a cure for the fungus, but
in the meantime, captive breeding of frogs in safe locations
is ensuring that at least some of the species will survive
(an amphibian equivalent of Noah's ark). Should a way of
eradicating the fungus or inoculating the frogs be discovered,
they will then be reintroduced.
"This is not an ideal solution," scientists say. "Preventative
medicine is always preferential to a cure. It would be better
if we took better care of the planet that these vanishing
frogs and we ourselves call our home."