The world of poison dart frog toxicity

Greetings from Scaly Slimy Spectacular! If I were to ask you what the most dangerous animals are in our building, you’d probably mention the Gaboon vipers, African slender-snouted crocodiles, or many rattlesnakes we have in habitats here. But how about the poison dart frogs? The answer may surprise you.

“Poison dart frog” is the general term for a group of colorful frogs from Central and South America (the taxonomic level is Family: Dendrobatidae). Currently at Zoo Atlanta, we have three different species representing three different genera – those being Oophaga, Phyllobates, and Dendrobates. These frogs secrete noxious chemicals (aka, poison) through granular glands that cover the skin. That means there is no central poison gland in frogs, unlike a venomous snake that may have paired venom glands located on the head (which is partly what gives the triangular head-shape in vipers). In fact, all juvenile and adult amphibians have granular glands that cover the body – so even the slimy salamanders and the chorus frogs you can find here in Atlanta have poison glands. But obviously some poisons are more dangerous than others.

Let’s jump straight to the most dangerous toxin our Phyllobates poison dart frogs secrete – batrachotoxin. When a predator consumes one of these frogs, the secreted batrachotoxin goes to work, attacking the nervous system and causing convulsions, muscle contractions, salivation, and even death. It is certainly in a human or predator’s best interest to spit out the frog immediately, as there is no effective treatment or antidote to the poisoning. In fact, that is why many of these highly toxic frogs are so brightly colored. It’s an evolutionary adaptation called aposematic coloration and a way to tell potential predators “Hey, I’m dangerous!”

Now I bet some of you regular Zoo visitors have seen our poison dart frogs in the same habitats with other animals, or maybe you have even seen one of us Herpetology Team members pick them up. So what gives? Well, although more research needs to be completed, it is hypothesized that poison dart frogs gain their toxicity from their diet – specifically formicine ants and other small invertebrates. Here at Zoo Atlanta (and nearly every other organization that keeps these frogs), the frogs are fed a different diet than that of the wild. We mainly feed our frogs fruit flies, crickets, springtails, and bean beetles. This allows us to handle our frogs risk-free.

Finally, I want to give an answer to the original question – how do poison dart frogs rank among the other perceived dangerous animals in the herpetology animal population? Well, there is a reason the frogs are called poison “dart” frogs. That is because some native people of Colombia cover their blowgun darts in the toxic secretions of the frog – so the toxin is directly administered into a prey animal’s bloodstream via the blowgun dart. This happens to be extremely effective. I have heard of monkeys and other small mammals dropping dead in just a minute or less, and even larger mammals (such as jaguars) succumbing to the batrachotoxin in under four minutes. Using the blowgun method by humans, poison dart frogs can be considered very deadly, but poison dart frogs by themselves are relatively harmless unless consumed.

I hope all of that got you even more interested in these amazing animals you can see here at Zoo Atlanta!

Noah C.
Keeper III, Herpetology