CAN BE A MATTER OF LIFE OR DEATH
arsenals used by plants and animals throughout the world in waging chemical
warfare are fascinating. Finding commonalities and dissimilarities between
various groups reveals how diverse the natural world can be. The primary
function of injection by many venomous animals is to acquire their prey,
although toxic chemicals are also used defensively.
of venomous injection methods include the nematocysts of a jellyfish,
the tail stinger of a stingray, and the stinging hairs of some caterpillars.
Even some plants, such as the common stinging nettle, are technically
venomous as tiny hairs on the leaves and stem can penetrate the skin
and release histamines when someone brushes against them. My grandchildren
are no longer a threat to stinging nettles because all have learned
firsthand the perils of tramping through a patch of this well-armed
A few of
the world's mammals qualify as venomous, the best known being the male
duckbill platypus of Australia. A sharp spur on each hind foot is connected
to a venom gland and a duct that transfers the toxin to the barbed structure.
The short-tailed shrews of the eastern United States have toxic saliva
that enters the body of prey, or would-be predators, when the shrew
organisms differ from venomous ones in that the noxious chemical is
not injected but can be injurious if eaten or touched or even inhaled
(e.g., smoke from burning poison ivy). Some toxins can enter the bloodstream
through a cut or the lining of mucus membranes. Poison ivy produces
an oily substance that causes dermatitis in some people upon contact
with leaves, stems, or roots. Death angel mushrooms and poison hemlock
produce chemicals that are harmful if eaten. Common garden toads secrete
distasteful toxins from skin glands.
birds have yet been discovered and presumably none exist. But the pitohui
birds in New Guinea have poisonous skin and feathers. The chemical composition
of the poison is similar to that in the skin of dart poison frogs of
Colombia, South America. These deadly little frogs secrete a toxic chemical,
a type of alkaloid that makes them unpalatable to other animals. If
eaten or injected, as with the tip of a man-made dart used by Colombian
natives to hunt prey, the toxic material has an immediate effect on
the nervous system.
toxin of the New Guinea pitohui birds was unknown anywhere else in the
animal kingdom except in the poison frogs. The chemical is a powerful
deterrent, and predators avoid poison frogs as a source of prey. Presumably
the poison operates in a similar fashion for the New Guinea pitohui
birds by discouraging typical predators such as snakes, other birds
and mammals from having an otherwise tasty meal.
toxic of the New Guinea birds is the hooded pitohui, a small, orange
and black, foul-smelling creature with a crest like a tufted titmouse.
While collecting and preparing the first specimens of hooded pitohui
birds, the investigators suffered from bouts of sneezing, along with
numbness and burning of the mouth and nasal lining. As is often the
case with scientific discoveries, the local populace already knew about
the phenomenon. A 1977 book on folklore of the Central Highlands Province
in Papua, New Guinea, mentions that local residents said the skin of
the hooded pitohui "is bitter and puckers the mouth." They
referred to it as a "rubbish bird" and advised that it not
be eaten "unless it was skinned and specially prepared." I
have not sought out the recipe.
in our knowledge of the natural world is of value if it raises our intellectual
consciousness. Such discoveries help us to better understand the differences
and similarities of various organisms as well as to appreciate the many
ways nature has of solving problems. Knowing that natural poisons (including
injected venoms) are an everyday part of nature makes it all the more
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