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Although it has been suggested for years that difference in captive diet is the reason captive frogs lose thier toxicity, a recent study proves that certain ants in the wild dart frog diet make them toxic. Now someone just needs to feed these ants to captive frogs and see if they regain thier toxicity. Paste the text below in your browser and check it out.

http://dsc.discovery.com/news/briefs/20040510/poisonants.html

Gator,
It is to my understanding that the ants eat a certain plant that is toxic and this causes them to become toxic. Then the ants are consumed by dart frogs and this is how they get their toxcicity (I am sure that is not spelled right). It is sort of a chain reaction type of deal.

TonyT

Did you check the webpage I cited in my post? This new research shows the key to be alkaloids from the ants in thier diet. The study was on dendrobates pumillo. I personally believe it varies from species to species since available food is different depending on the region. Ants could be a common food source pretty much anywhere though. Also check this webpage:

http://www.pnas.org/cgi/content/abstract/101/21/8045

Gator,

I think Tony was just going one step further than the article you listed. Yes, the ants have been found to be the insect carrier of the alkaloid. However, the ants likely get the alkyloid from a plant that they consume . . . just like the Monarch butterflies cited in your article.

I have always wondered whether feeding milkweed bugs caught on a milkweed plant to darts would cause them to become toxic again. Probably not, it's probably a different alkyloid, but it's worth scratching your head about.
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Homer W. Faucett III, esq.
Purveyor of Trivialities and Fine Nonsense

What ant eats plants? Leafcutters only eat a fungus they grow using the leaves, and harvester ants only eat seeds, but do they eat toxic ones? Is there an ant that eats poisonous plants? I'm no ant expert, but would be interested in finding out if anyone knows. I agree it's more likely the alkaloids must come from something the ants eat as opposed to being produced by the ants themselves. I'll have to do some research on the ant species mentioned in the study. I wish it was more specific about the species. The families they mentioned include many ants. If anyone else finds anything I would be interested. Thanks for both replies so far, I don't intend to be contradictory to anyone, I want to learn as much as anyone.

Numerous ants eat secretions and nectar from plants, and there are several species of ant plants that have a symbiotic relationship with the ants, feeding the ants and providing shelter for them in exchange for defense against herbivores. That is one mechanism through which ants may be exposed to alkyloids. There are several others that can be hypothesized, but I will leave that to the researchers.
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Homer W. Faucett III, esq.
Purveyor of Trivialities and Fine Nonsense

Here's what I've found:

The crucial samples came from Ralph Saporito, now at Florida International University in Miami, who noticed formicine ants on Heliconia plants during the rainy season. Frogs cruise these plants too, raising tadpoles in water pooling at leaf bases.

The finding is news for ant specialists, too, says Diane W. Davidson of the University of Utah in Salt Lake City. Although formicine ants use an alkaloid pheromone, they defend themselves with formic acid. Until this report, Davidson says, she had not heard of other alkaloids in these ants. She suggests that the ants may get toxins or toxin precursors from their diet.

Looks like the the plant theory is correct. I don't know much about heliconias, but they have large flowers, perhaps the ants get the alkaloids from the nectar as you said.

n/p
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Homer W. Faucett III, esq.
Purveyor of Trivialities and Fine Nonsense