Maybe the Dingoes Ate Your Toad

This story about toad-licking dogs in Australia is amusing and may even be true, but it raises a question: Don't cane toads secrete their psychoactive toxin to discourage predators? Or rather, doesn't this trait persist because it makes toads that have it less prone to being eaten and therefore more likely to have lots of offspring? If predators actually enjoy the toxin, what's the point (evolutionarily speaking)? Does the toxin only repel predators native to Australia (so dingoes don't like it, but Irish setters do)? Or are the toads so much fun to have around that predators avoid eating them?

Update: It turns out the cane toads are not native to Australia either.

Comments

[taktix]

I would guess the dingoes developed a tolerance to survive themselves. I mean, 1/3 of Australia is a huge fucking desert.

[Duckman]

"Ms. Pickering said she believes some of the dogs are becoming addicted, as she has seen them 'going back to have a second go.'"

This is also how most people judge whether a human is "addicted" to a drug.

[jpe]

Once you drop the nonsense of evolution and adaptation, it's readily apparent that psychoactive toads are a gift from a benevolant designer.

[Travis]

"I'm not NOT licking toads."

[kelley]

Mason Williams reference: http://www.anvari.org/fortune/Best_Fortunes/1447.html

[anon2]

No need to read the book, when you can watch the movie.

[daksya]

If predators actually enjoy the toxin, what's the point (evolutionarily speaking)?

To keep the toads alive, of course. A dead toad has ceased to provide.

[Jacob T. Levy]

A) I don't believe it and B) even if it's true I have no idea whether the native/ non-native distinction is what's doing the relevant evolutionary work-- but anyways dingoes aren't native to Australia acorss evolutionary-scale timeframes. They've been there only tens of thousands of years. If the toads' toxin is repellent to snakes, crocs, and big lizards, that would've been enough for an evolutionary advantage-- and it's not implausible that reptiles and mammals would have different biochemical reactions. I think that up north where the toads live there weren't even marsupial predators (e.g. the now-only-Tasmanian Devils and Tigers).

[MattXIV]

It's probably an issue of quantity. Humans, for example, may eat a handful of psilocybin-containing mushrooms periodically for kicks, but we wouldn't be able to make them a dietary staple.

[Paul W]

Have you ever looked at your paws? I mean, really loooked at your paws?

[Highroller]

You would have to be a French dog to eat a toad.

[Ron Hardin]

You've missed the funniest documentary movie ever ``Cane Toads, An Unnatural History (1987)''

Available at Amazon, the last I saw.

[ChuckWalla]

Here in Arizona you smoke'm if you've got 'em

http://en.wikipedia.org/wiki/Colorado_River_toad

sorry, I don't know how to do the little linky thing

[Evan]

"but it raises a question: Don't cane toads secrete their psychoactive toxin to discourage predators? Or rather, doesn't this trait persist because it makes toads that have it less prone to being eaten and therefore more likely to have lots of offspring? If predators actually enjoy the toxin, what's the point (evolutionarily speaking)?"

Jacob, this is a rather simplistic view of evolution & natural selection, and the logic doesn't really follow. First, if the dog is only licking the toad, but not eating it, then, it doesn't really make much of a difference evolutionarily speaking. The toad's life was niether saved nor taken by the trait.

Second, it's a matter of quantity, as MattXIV notes. A dog might get a little somethin'-somethin' from licking the toads, but if it ate the toad, things might not be so psychadelically fun.

Third, throughout the evolution of the toad, the dog most certainly hasn't been the most persistent and prominent predator of the toads.

Fourth, evolutionary developments are not infallibly perfect. Look at humans---our brains still think that we're in the Ice Age, and we need to fatten up for winter. Instead, it gives us high blood pressure and cholesterol. Evolution is painfully, unbelievable slow---and if, say, dogs discovered this trait recently, even hundreds of years ago, that's simply not enough time for evolution to weed out that trait.

[Ron Bailey]

Jacob: You probably already know this, but Cane toads are not native to Australia--they come from the Americas where dogs apparently have other ways to get high.

[JW]

I only lick toads for the taste.

[gaijin]

When I was, um, I mean, I have heard that when you are tripping, food isn't really something you spend alot of time or effort on...so maybe a licked toad, while risking death, is just doing his part for the greater good by placing predators in a more, um, easy-going state of mind?

[M']

I think dogs may actually have a tendency to lick toads by nature. I'm not lying. My girlfriend took her husky to Puerto Rico and it licked the one of the local toads and had a violent reaction to it. I guess it took quite a bit of Benadryl to bring the mouth and throat swelling under control.

[Douglas Fletcher]

So I wonder if all those limey knock-offs down in Australia are still eating toad-in-the-hole?

[Brian]

I can attest that dogs LOVE licking Colorado River Toads.

[peachy]

Is it wrong that I first read "Irish setter" as "Irish settler", and thought that made perfect sense?

(Which gives the perfect opportunity to trot out some more Simpsons' inebriation quotes - "All this drinking, violence, destruction of property. Are these the things we think of when we think of the Irish?" and "I'm going to bring them something that man has searched for since the dawn of time. / A sober Irishman? / Even rarer.")

[mediageek]

Peachy, don't forget the eternally classic toast "To alcohol! The cause of-and solution to-all of life's problems!"

[The Prime Bloody Minister of B]

Douglas Fletcher better watch 'is arse. Nobody calls Aussies limey knock-offs without gettin' 'is arse booted.

[ChuckWalla]

Brian

I wonder if they get the same 5 minutes of the most intense tripping as you get from smoking the venom? or so i've heard it's like that.

[peachy]

Oh, mediageek, that is such a brilliant episode... perhaps the most perfectly libertarian one of them all, too. It also features the classic "We're going out, Marge! If we don't come back, avenge our deaths!" which later is boiled down to the pithy "not back, avenge deaths," perhaps the most perfect farewell of them all.

[Todd Fletcher]

It's obvious how this works as a defense: the dog gets too fucked up to remember to eat the dog. Brilliant.

[mediageek]

Peachy, I agree. That one is in my top five favorite episodes of all time.

Plus don't forget the scene involving the catapult and the cat.

[Mr. F. Le Mur]

running in circles, having bright red gums, and frothing at the mouth.
I hate it when that happens.

[Eddy]

We should make a Tequila like beverage with a little toad in the bottle.

At least that explains the frog kissing to find a prince in the fairy tale.

[Deus ex Machina]

Update: It turns out the cane toads are not native to Australia either.

All due to the Simpsons.

[Darwin's toady]

Exploding Toads - Anybody else read this item from the same page on the original link?
http://coloherp.org/cb-news/Vol-32/cbn-0511/CaseSolved.php

In a nutshell the formula for an elegant method of natural toad control is: Cr+fg = td/e
where Cr=Crow, fg = foie gras, td = toad, and e=explodes. Natural evolution solution = best.

Woo - hoo! Demo this Mythbusters!

[Bill Newman]

As Evan wrote, "Third, throughout the evolution of the toad, the dog most certainly hasn't been the most persistent and prominent predator of the toads."

To elaborate on this, consider caffeine, and the related drugs theobromine and theophylline present in chocolate and tea. My understanding (from many many years ago when I last studied biology, so possibly out of date) is that their job #1 is to kill insects that eat the plants, and their strongest effect against those insects is when combined with other neurotoxins present in the same plants. But theobromine is enough of a broad spectrum toxin that it doesn't just kill bugs, it can easily kill a dog which finds some chocolate. Then, somewhere in the many generations between the common ancestors of dog and man, something changed --- likely adaptation of human ancestors who got a lot of their calories from plants --- so that humans cope with the toxins better, getting just a buzz even in dog-killing doses. And even with humans' relative resistance, too much caffeine is a problem, enough so that it would probably be dangerous to try to make coffee-bean chili a staple in your diet even if other food were scarce. So fun from modest doses isn't necessarily inconsistent with a toxin providing an evolutionary protective benefit.