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The cane toad - bane of Queensland, and many other sites where these durable critters have been introduced. These toads are meaty, brazen beasts who make no attempt to escape because they are well protected by their poison. The Australians boast of various horrors perpetrated on the toads in the name
of toad control, but thus far their numbers are still increasing (the toads, that is).
I propose that better toad control could be achieved by allowing native australian predators (for example: the quoll) to dine on toads with impunity.
A well-meaning group of foreigners intent on improving Australia would begin a colony of quolls. Small quantities of bufotoxin would be added to the quoll chow. Small baby quolls hanging on to their moms would also begin to develop resistance to the toxin. When these baby quolls let go of the nipple and begin looking for meat, they are initially provided a diet of straight cane toads - initially washed of most toxin, but gradually stronger and stronger until these quolls can feast on full grown toxic toads and laugh about it.
These poisonproof quolls are the released into Australia. Never having eaten anything but toads, and with loads of plump toads in ready supply, they will prosper. Like them, their progeny will have acquired bufotoxin resistance by the time they are ready to go it alone. Eventually, the toad population will be controlled by these native sons and daughters.
This strategy might be used in other contexts (by the same well meaning foreigners) where native predators are in decline, and toxic alien introduced species abound.
What is a quoll ?
Say "aahhhhh" [normzone, Apr 30 2005]
Australian monograph on toad control
Mosty this is about developing a GMO virus! I can imagine what sort of reception that would get on the HB. It turns out that quolls think they should be able to eat cane toads, and when the toads show up, the quolls die off. We just need to give quolls the power to realize their dream! [bungston, Apr 30 2005]
[bungston, Apr 30 2005]
Beavis and Butthead's ultimate solution. [jaksplat, May 01 2005]
If you can get hold of it, see it. [wagster, Jun 21 2006]
||And then we ardently hope that the explosion in the quoll population won't obliterate their natural food source after obliterating the toads . . . ?
||You're assuming (I think) that resistance
to the toxin can be built up by gradual
exposure - this is true for some toxins,
but not all (don't know about
Also, I'm not
sure how the resistance (if any) would
be passed on to the offspring - are you
suggesting that small amounts of
bufotoxin would pass into the mother's
milk, and thereby acclimitize the young?
Again, I'm not sure if this would happen
If it were this simple
for a native predator to develop a way
to gain access to an abundant food
supply, chances are it would happen
anyway. For instance, some quoll
somewhere would have nibbled on baby
cane-toads (?) or on rain-washed road-
kills or some other partially-detoxified
cane-toad flesh, developed a little
resistance and taken it from there.
Nature generally does the simple things
||I think that with eating very poisonous things, there is a certain "energy of activation" that must be overcome - in this proposal, artificially. To become immune to a toxin, one must have chronic non-lethal exposures. An animal that eats something that makes it feel sick will not eat that thing again. With the toads, a lot of animals die the first time, and ones that don't are not trying toad again. It is unlikely that a young quoll could serially encounter foodstuffs with subtoxic levels of toad venom in the wild that did not make it at least feel sick and develop toadphobia.
||As for whether one can build immunity to bufotoxin, that will take some research.
||//I think that with eating very
poisonous things, there is a certain
"energy of activation" that must be
overcome// Well, that is my question.
There are some toxins for which it is
possible to build up a resistance, and
some for which it is not, and this is kind
of fundamental to the cane-toad
business. And I'm still not sure about
Have animals in
the cane-toad's original environment
developed a way around its toxicity?
(They have presumably had several
million years in which to do so.)
||Digitalis is a cardiac glycoside, and so should be metabolized the safe was as bufotoxin. The qquestion: do people taking high doses of digitalis become accustomed to its effects? My preliminary search shows that iti is possible to alter the metabolism of digitalis with other drugs (usually this inhibits metabolism and the person winds up with too much digitalis in the blood).
||Maybe there is a baking doctor or pharmacist who knows this answer off the top of his or her head, or where to find it. In the meantime I will keep looking.
||Quolls look a lot like possum. Do they taste similar?
||Bufotoxin is actually a collection of
compounds (including the one you refer
to). But if I were a cane-toad with not
much else to do, I'd have spent the last
few million years evolving a toxin
system that couldn't be acclimatised
As a related question,
what preys on quolls? And (**if** this
whole idea worked), would the quolls
become inedible by virtue of the
bufotoxin sloshing around in their
bloodstream? You might find that
superquolls become the new plague.
||//But if I were a cane-toad with not much else to do, I'd have spent the last few million years evolving a toxin system that couldn't be acclimatised to.//
Whoa! Your Darwinism is peeking out from beneath your Lamarckism! And it's causing me mental anguish!
||I notice in one of the links that dragonfly larvae take quite a toll on toad tadpoles.
Could native dragonfly populations be given optimum conditions with temporarily species saturation as a goal towards the end of severely reducing cane toad's tadpoles?
I do notice elsewhere that dragonfly larvae will eat ANYTHING smaller than they are, so it may not be the best solution. I suppose that the toads when adult will eat the dragonflys mis-balancing the solution.
||I've heard that the crows of Queensland have learned to flip little toads on their backs and peck their guts out, thereby avoiding the back-mounted poison glands - but is that just a rumour?
||I wouldn't put it past a crow.
||The only good toad is a dead toad.
||A toad deserves as much love as any other
animal - Toads are the new dolphins and
can cure any illness in those who swim
with them every day with open mouths.