Feasting Frogs By John F Taylor

I e-mailed some of my close friends and colleagues to ask them what they would be interested in reading about as far as herpetological articles go. Being the sporting type they are, each one responded with similar interests, which for some odd reason seemed centered around amphibians and frogs in particular. One e-mail however was very specific,

“I want to know about the North American Sasquatch AKA Yeti AKA Bigfoot. Interested in its way of life i.e. eating, mating, social habits. If you are weak and can not help me then I want to know about those frogs that as adults eat snake.”

After reading this email the rest of the crew also chimed in that they would also like to know more about this frog or toad. Surprised it would not only attack, but that it would actually eat it. After admitting my weakness of Yeti knowledge, I ventured to write an article of snake eating Anuran. However, before getting started I would like to cover some of the generalities of Amphibians, particularly those related to frogs and toads.

The History of Toads & Frogs

Warts, Witches, & Whoa what a high?

Tales and folklore abound throughout the world of amphibians and the evils they are capable of, but is within the history of Toads and Frogs that we will journey upon a long and convoluted trail of misconceptions, myths, and misnomers in which the Toad has seemingly come away with the most notorious reputation. Perhaps the most recognized, or at least the most commonly known myth is, this; anyone touching a Toad will eventually come to discover that they have also developed warts similar to that of the Toad that was molested. To date, there has been no scientific data to confirm this; however there are still peoples and cultures that do believe this tale.

In Medieval Europe, Toads were seen as a Witch’s familiar or pet. This story can most likely be attributed to the local herbalists who knew of herbs and animal properties that could heal the sick or if you had a grudge could make someone else sick. It is almost certain that native Indian tribes of South America were ingesting the toxin found in Bufo alvarius Colorado River Toad before it was even discovered in by science in the toads themselves. This is because scientists found the chemical 5-MeO-DMT in the natives snuff boxes and discovered the effects of this extremely potent psychoactive toxin first hand.

Bufo alvarius is considered to be one of the most toxic species of Anuran specifically Toads, due to the large glands in its legs as well as its kidney shaped parotid glands located behind its head. Most toad poison has within it a specific toxin called bufotoxin which affects the cardiac activity while simultaneously lowering the pulse rate[i]. It is also within Bufo alvarius we find the powerful psychoactive known as 5-MeO-DMT[ii]. This is no doubt where the “myth” of toad licking was started. However, in all the articles that I have read both scientific and non-scientific the results of toad licking were the same. Bad taste, numbing of the tongue in some cases but no feeling of being high or anything of the sort, before going on with the rest of this article I have never licked a toad nor would I ever condone such actions whether it be in the name of science or not. Just be safe and not a statistic, we have enough trouble in this industry already.

Hideous hoppers & Poisonous Prima Donnas

The Bufonidae family does not hop as do their Anuran South American cousins; their shortened legs and stocky frames presumably inhibit this behavior and this is most likely the reason that many within the Bufonidae family are “earth” toned or colored. It also likely this is the reasoning behind some of them developing their irritating secretions which in some species are actually able to be squirted at will.

Meanwhile, on the complete opposite end of the spectrum quite literally actually as we will discover we have the family Dendrobatidae which are somewhat akin to prima donnas in care requirements as far as the vivarium are concerned anyway. The genera found in this family are all extremely small and highly toxic even to the touch in the wild [iii]. These frogs are known by many common names depending on who you speak to, Dart Poison frogs, Poison Arrow, and Poison Dart are all names attributed to some of the most colorful amphibians to ever hop the earth. These diminutive little creatures have been used probably since recorded time to make the arrows, spears, and darts of the native Indian tribes of South America all the more lethal to their quarries of the forest in which they hunted.

Distribution

The Anura order as they are known by scale counters (Taxonomists) Toads and Frogs to you and I are amazing creatures which inhabit most of the world, being found indigenously to every continent except for Greenland and Antarctica. They are also found in Madagascar, New Zealand, and many other Pacific Islands. There are currently around 4,400 species of Anuran in the world with approximately 250 of these being Bufo or True Toads.

The Discoglossid suborder is also a singular genus known as Discoglossidae which contains only two species commonly known as the Painted Frogs. These frogs are typically found in sunny open swamp waters, mountain streams, and brackish waters of the Mediterranean. These frogs are very close to the culprits that eat snakes. It is interesting to note that both the Bombina sp. and the Discoglossus sp. are both cannibalistic and the Discoglossus specifically is known to eat young fish and earthworms (suspiciously snake like don’t you think.)

The next suborder of Mesobatrachia contains within it 5 genera and these are known as intermediate frogs. Within this suborder we discover one of the most (in my opinion) interesting animals to ever live in the water. This animal was first described by Laurenti in 1768. It is the Surinam toad known as the Pipa pipa. In my experience these oddly shaped frogs will eat anything that is offered and when they do, it is like watching world champion food eaters. They simply open their large mouths and use their forelimbs to stuff whatever hapless morsel has happened to cross their snout. According to some reports they are capable and will take small dead animals. Personal experience has shown that are very capable of taking stunned mice, large goldfish 2 inches and larger, and large earthworms all with the ease of a hot dog eating champion.

Finally when it comes to modern frogs we look into the suborder of Neobatrachia. Within this one suborder we are faced with 24 genera [iv]. It is within this last order that we find our not only our largest family Leptodactylidae but we also discover our fiendish feasters of snakes. Surprisingly enough, one is actually a Treefrog while the other is a True Frog.

Snake Eating Frogs

We will first look at our most innocent looking swallower of serpents. I am sure you will doubt this when you read it, but those cute and cuddly little frogs known as “Dumpy Frogs” are vicious killers. It is hard to believe, the Litoria caerulea better known as White’s Treefrog have been not only documented but actually caught in the act not to mention preserved as a museum specimen consuming a snake! In an Australian museum there is just such a specimen that was collected in 1932 at Currumbin on the Gold Coast and then donated to the museum. The specimen or specimens depending on how you look at it are supposed to be in great condition except of course for losing their original color. The L. caerulea is frozen forever with his last meal which happened to be a Keelback snake Tropidnophus mairii formerly described as Amphiesma mairii half way in its mouth.

It is of interesting note that these Tropidnophus sp. are known to consume frogs as part of their natural prey items. It is known that they are a rear fanged snake and the venom is supposedly both potent and dangerous. We are left to wonder how this particular event unfolded. Was the Keelback Tropidnophus mairii full from a meal when it uncaringly passed by this harbinger of death thinking to itself that it was safe due to its knowledge of other such frogs leaping away for fear that they too might be consumed in some sort of late dinner plans.

Now we come to the most infamous snake eating frog of all times. These little hoppers of horror have actually been featured in B-rated horror films taking over the world. A scenario that is not so far from the truth today as we will we see. The Rana catesbiana or Bullfrog has been one that is targeted for habitat (indirectly) and wildlife (directly) decimation according to wildlife biologists?[v]

This particular species of Bullfrog is thought to be an introduction from somewhere in the early eighteenth century to the Western United States. The introduction is not clear as to why it was brought; a child’s pet, a food source, or maybe even a pest control device for crop farmers. Since that time its legs have been somewhat of a delicacy being consumed by Americans typically living in the South and the South Eastern United States.

Regardless, of any opinion it is a known fact that Rana catesbiana are an excellent pest control species. However, so is the Bufo marinus or Cane toad which was introduced to Australia for sugar cane crop protection against insects. This particular species is a great asset to pest control however; it is also a highly toxic species for anything that may attempt to make it a prey item.

Until recently, there were no natural predators of this toxic toddler which has been responsible for many deaths of domestic and wild animals which have attempted to consume it. Today however, science has recently discovered that some snakes have evolved in order to be able to consume this “nuisance”. With this discovery it is hoped that this will allow the current populations to be brought under control.

Within the United States however we are not as yet so lucky. According to the reports that I have read from several wildlife biologists there is no clear cut way to control the current populations because there are not currently enough natural predators that can compete. In one season an adult Bullfrog Rana catesbiana can have several clutches of over 20,000 eggs each. While their natural predators such as Garter Snakes Thamnophis sp. do give live birth these young are extremely vulnerable to consumption by the very items that they will prey upon as adults. So it is obvious that unless Garter Snakes Thamnophis sp. suddenly begin giving birth to 20,000 young at a time that they will be in a constant decline.

The Bullfrog is R. catesbiana is also documented as being able to leap twenty-six feet. This may seem an inappropriate statistic to place in this article at first; considering however that most birds that feed on insects in the same areas are typically flying at altitudes that bring them within this striking distance. This is also a hazard for bats as well, who are feeding on frogs within the ponds but at the same time are documented as being meals for the Bullfrog R. catesbiana as well. With such a voracious appetite and a breeding regimen that would make a rabbit jealous is it any wonder that these feasting frogs are a worrisome pest to the wildlife biologists.

This leaves out the fact that the Bullfrog R. catesbiana can and does dine on the native frogs found within its home pond. They are also known to eat turtles amazingly enough. There digestive juices within their stomachs are actually strong enough to dissolve the shells. The skin of the Bullfrog R. catesbiana is also a repellent to any fish which might want to make a meal of them.

i F.J. OBST, Dr. K REICHTER and Dr. U JACOB. 1984 The Complete Illustrated Atlas of reptiles and Amphibians for the Terrarium. T.F.H. Publications, Inc New Jersey

[ii]

[iii] Taylor, J F Reptilia Issue #44 2006 Poison Frogs & their Vivaria

[iv]

[v] ROSEN, P University of Arizona Department of Ecology & Evolutionary Biology Tucson, AZ 85721