There's something about spiders that gives
most people the creeps, instilling a sense of fear and loathing upon
seeing one. It's as though there's a part of the human brain that
perceives the form of a spider as dangerous or threatening. Perhaps
those deep dark feelings we get when we see a spider are echoes of
an ancient human behavioral response known as instinct. Most of the
thousands of species of spiders on this earth carry a venom that is
virtually harmless to humans, but there are a few species which carry
a deadly venom. Based on primitive human experiences a permanent message
has been embedded in our genetic make-up, one that warns us that spider
= danger. And when we see a spider that is as large as a dinner plate,
we get the creeps BIG TIME.
But the goliath bird-eating spider
is pretty harmless to humans, as are most species of tarantulas. They
do carry venom in their fangs and have been known to bite humans when
threatened, but the venom just causes swelling and mild pain for a
few hours (like a wasp sting). Tarantula bites to humans are usually
in self-defense and don't always contain spider venom - what is known
as a "dry bite".
The most dangerous thing about the goliath bird-eater
is its ability to flick urticating hairs
from its body at any creature it perceives as a threat, including
humans. This is not a species of tarantula you'd keep as a pet. The
tiny, almost invisible hairs that it voluntarily sends floating through
the air are extremely irritating to our skin, and can cause real problems
if they got into delicate mucous membranes around eyes and mouth.
As hunters, tarantulas can be fearsome
predators. Tarantulas don't have any special techniques, such as building
intricate webs, or leaping great distances, for hunting their prey.
They use good, old-fashioned stealth and strength, very much like wild
cats. They sneak up on their prey and pounce on the unsuspecting victim,
inflicting a fatal bite with venomous fangs.
One fascinating feature of goliath
bird-eaters, as well as some other tarantula species, is their ability
to make noise. We don't normally associate spiders with noise, like
we do with dogs, cats, birds, etc. We are accustomed to seeing spiders
silently, stealthily crawling across walls, floors, and the sidewalk.
But when feeling threatened, the goliath bird-eater is capable of making
a pretty loud hissing noise by rubbing bristles on its legs together.
Called stridulation, it can be loud enough
to be heard up to 15 feet away!
Creepy Crawlers
Tarantulas use their fangs for
subduing their prey and carrying it to their dens (or to a safe location)
for devouring at their leisure. They don't have teeth for tearing and
chewing their meals so they regurgitate digestive juices onto their
victim. These digestive juices break down the soft tissues so that the
spider can slurp up its meal. All that's left when the spider has finished
its meal is bones, skin, fur and/or feathers. The goliath bird-eating
spider has been known to take young birds from their nests for its mealtime
pleasure - hence the name "bird-eater". Tarantulas eat frogs,
small snakes, beetles, lizards, and even bats.
You think that's creepy? Believe
it or not there are people in South America who eat tarantulas.
Many of us in developed countries are repulsed by the idea of eating
insects or spiders, but it actually makes sense if you think about it.
They are the most plentiful living things on earth and they are a good
source of protein. I've heard tarantulas roasted in their own skins
over a campfire are pretty tasty. I think I'll pass....;-)
Location: This big guy is
found in the coastal rainforests of northeastern South America,
in the jungle.
Facts: These spiders are
a sub-species of tarantula, which are the largest spiders in the
animal kingdom. The biggest goliath spider on record had a legspan
that measured just over 11 inches across! That's big enough to
cover a dinner plate.
The Scientists Who Study this Cool
Stuff?
Biologists, Arachnithologists, Zoologists.