Poisonous Frogs

[Zinjanthropos]

Watching Nature channel this afternoon. They talked for a bit about poisonous frogs from Madagascar. These frogs have markings on them that supposedly indicate that if eaten they're fatal to the predator. 

What I can't figure out is this....'if eaten' implies that they do get eaten on occasion, but the predator dies. The markings obviously do not prevent a frog from being devoured. With the predator dead, how is the message spread to other predators that the frog is lethal? 

The only thing I can figure out is that the predator species benefits because the dead don't get to pass on their brightly marked frog eating traits, thus improving the predator stock. The frogs benefit by this also since tendencies to eat them are slowly weeded out of the predator's genetic makeup. Two deaths due to poisoning, one from each species, actually contributes to the welfare of both.  It seems to me that the frog's markings have more to do with surviving predators not recognizing Kermit as a meal than being aware of poison.

Seems a little odd that both species die to improve their lot. I can only assume that the frog's evolved away from becoming quicker, larger or even camouflaged because it didn't work as well.

[Secular Sanity]

That’s a good question and it's interesting.

https://en.wikipedia.org/wiki/Aposematism#Evolution

[Zinjanthropos]

That’s a good question and it's interesting.

https://en.wikipedia.org/wiki/Aposematism#Evolution

Thanks for the link, very interesting read.

Why the mimics are successful is puzzling to me. Surely they get eaten without causing discomfort to the predator, unless they just taste awful. However the predator doesn't die in this case. Could it be possible that the mimics are a good reason some of the more unpalatable creatures get eaten? If a bird for example gets used to dining on an insect that's only a mimic then there's a chance that perhaps one day it chooses the poisonous creature, the one being mimicked. Consuming mimics might successfully fool a predator into eating the wrong creature, thus killing the predator which helps the mimic population.

[Secular Sanity]

Why the mimics are successful is puzzling to me. Surely they get eaten without causing discomfort to the predator, unless they just taste awful. However the predator doesn't die in this case. Could it be possible that the mimics are a good reason some of the more unpalatable creatures get eaten? If a bird for example gets used to dining on an insect that's only a mimic then there's a chance that perhaps one day it chooses the poisonous creature, the one being mimicked. Consuming mimics might successfully fool a predator into eating the wrong creature, thus killing the predator which helps the mimic population.

No, I don’t think so.  There’s a few different types.  From what I gather, the mimics piggyback on the aversion that is already present in their habitat.  They think that aposematism itself is successful because it may have originally developed in insects that can maintain populations at a high density, allowing for a number of the individuals to be killed in order to educate the predators.

Batesian mimicry, where a harmless mimic poses as harmful.

Müllerian mimicry, where two or more harmful species mutually advertise themselves as harmful.

Mertensian mimicry, where a deadly mimic resembles a less harmful but lesson-teaching model.

[Zinjanthropos]

Mertensian mimicry, where a deadly mimic resembles a less harmful but lesson-teaching model.

I'm not sold on lesson teaching, especially when the lesson ends in death. It's tough to teach or learn a lesson when you're dead.

Pretty complicated stuff but I still think the so called warning patterns do not shout out BEWARE to a predator. I still think such markings are simply not recognized as food/prey but only because it's been bred into the predator over millions of years. Perhaps camouflaged prey is more recognizable as food than the colorfully marked. 

It would appear that the harmful colored creatures are more brazen than their camouflaged counterparts as far as openness and revelation is concerned. There's no need to hide, because predatory animals have evolved to recognize it's contrary to how natural prey reacts in their presence. Too difficult for predators to put 2 and 2 together, food simply does not normally present itself openly. Perhaps 'too easy' is not part of the predator hunting routine.