Giant African Rat Kills With Poisonous Mohawk

thebchuckster writes "The African crested rat has been known to kill local dogs, but researchers have just figured out how. After eating the 'poison-arrow plant,' the over-sized rodent stores its poison-laced spit in special hollow hairs in its mohawk. Then, when a predator grabs the rat, the animal gets stung with the poison and spit-tipped hairs which can sicken and kill."

Comments

Punk

[ctrimm]

Now that's punk.

Is this tool use?

[es330td]

I realize it isn't termite fishing with a stick like monkeys do but it is certainly manipulation of an object for the animal's benefit.

Re:Is this tool use?

[Chris Burke]

I wouldn't call chewing bark tool use. Nor grooming. It's "manipulation" only in the broadest sense of "using", but eating food is "using" an object for the animal's benefit.

Regardless of semantics, it is doubtful this is a sign of intelligence (which tool use is usually taken to suggest).

However it is a sign of awesome. Punk rock murder rats? Hell yes.

How did this evolve?

[improfane]

It does make you wonder how something so specific could evolve, the relationship between a poisonous plant and then the distribution mechanism.

I know that when I eat certain herbs, I sweat them out and smell strongly of that herb whereas other people I know are fine. I wouldn't be surprised if that is related, the rats that could not sweat out the chemicals died, those that could survived, the ones who sweated through barbs fared even better. Do animals that disperse poison even know it's a defensive mechanism?

How can they evolve that knowledge? Or is it aggression that is evolved too? A poisonous rat that is passive will probably not survive (it might still get eaten if it kills its predator) whereas one that is aggressive can attack its predator before it eats it.

What do you think?

Re:How did this evolve?

[flibbidyfloo]

I know that when I eat certain herbs, I sweat them out and smell strongly of that herb whereas other people I know are fine. I wouldn't be surprised if that is related, the rats that could not sweat out the chemicals died, those that could survived, the ones who sweated through barbs fared even better.

This is a common mistake made by people with a poor understanding of anatomy. Toxins in your body are excreted by your liver and intestines, not your skin.
Your sweat glands are there to regulate your temperature and are in no way designed to expel toxins.

People smell like things they've eaten because it's on their breath and on their hands.

Re:How did this evolve?

[flibbidyfloo]

It does make you wonder how something so specific could evolve, the relationship between a poisonous plant and then the distribution mechanism.

I wouldn't be surprised if that is related, the rats that could not sweat out the chemicals died, those that could survived, the ones who sweated through barbs fared even better.

Oh, and rats do not sweat. They regulate their temperature by constricting or expanding blood vessels in their tails.

Re:How did this evolve?

[Chris Burke]

Polar bear fur isn't hollow, but it is transparent, and directs sunlight down to the bear's skin like a coat of fiber optic cables, which is basically what they are.

But yeah, this isn't that unusual. Chewing and grooming are normal behaviors for rats. The hairs could have evolved for any number of reasons, and may have been quite different, maybe just specialized whiskers, before the poison plant made predator-poisoning the main selective pressure.

There's other cases of this kind of thing. For example, hummingbirds and the flowers they feed from will often undergo runaway evolution where the hummer's bill will be specialized to feed on the flower's specialized form that only the hummer's bill will fit. Even more amazing, there's a species on a Caribbean island where the males and females aren't just different in plumage, but also very different in bill shape which is unusual. Each of the two sexes feeds exclusively from two different but closely related species of flower.

The theory was that when the hummers first arrived on the island, there was only one species of flower, and the more aggressive males monopolized the flowers that had the highest nectar output while the females were stuck with the ones with lesser output. The result was that the higher output plants were cross-pollinated by the males while the lower output plants were pollinated by the females, setting the stage for the two populations of flowers to begin diverging into separate species, and for each sex of hummer to follow.

I dunno, I thought that was neat.

Re:How did this evolve?

[rubycodez]

But he can never hate you as much as God does, sinner.

Now repent and send me money for telling you so.

Re:How did this evolve?

[Genda]

That's because there are a lot of folks out there who have little tolerance for other people's belief. By the way that goes both ways. There were people burning each other over toasty coals because they disagreed on the finer points of Jesus, long before science nerds heckled the faithful. In fact the holiest church in all of Christendom, the Church of the Holy Sepulcher, has for generations had its door locked and unlocked by a Muslim family because the various sects of Christianity don't trust each other enough to give any one the keys. That my friend is being human.

So there is faith and then there's science. One is based on the unexplainable, and the other on empirical fact and data. The reason people get pissy about ID, is because its a belief looking for justification. That's really bad science, and when they catch scientists doing that (which happens every so often) they get their hands slapped and lab coats handed to them.

We now have so large a body of evidence, from so many fields (biology, material science, computer science, biiochemistry... it goes on and on) that we can actually point right at evolution as it happens/happened both micro and macro-evolution. Intelligent Design simply isn't necessary. If you choose to believe in God, you should be all the more joyful at your Lords cunning and brilliance to create space time that would result in atoms such that they can assemble themselves into mountains, or stars, or people. Its like epicycles, as long as you assume the earth is the center of the universe, you have to go through all kinds of ridiculous gyrations and complications to account for the behavior of the universe. The instant you give up trying to make it fit your pictures and just appreciate it the way it is, natural order arises and is self evident.,

I have no problem with people who believe in God. Science suggests a God isn't necessary for this universe to happen the way it happens/happened. Maybe God doesn't have an ego problem? That's where the faith comes in, eh?... Bon Apetite.

Pity

[ripdajacker]

I pity the fool who touches my mohawk!

hedgehogs do it as well

[SuperBanana]

My friend's hedgehog licked my hands and then started foaming at the mouth, and then spreading it on its quills. She explained:

https://encrypted.google.com/search?q=self-annoiting

If a hedgehog tastes something nasty, the froth it up and spread it on their spines. It works - if you get pricked hard, you can see a bit of an allergic reaction around the pricks (the spines are not like porcupines, ie, they don't have barbs. They're just somewhat sharp.)

How can they evolve that knowledge? Or is it aggression that is evolved too?

The same way any other trait evolves- the ones that do it survive better than the ones that don't.