The literature that HLs prey to a high degree on ants, it should be remembered, is based on observations taken ad nauseam.

Ants are found in much higher abundance in the desert than many other insects, so are a convenient prey item. They are also much easier prey for HLs to capture, as opposed to crickets, grasshoppers, and other jumping or winged insects, which would actually be much rarer fare for a HL than most people think. Such insects would be quickly to safety out of reach of the HL, and the HLs rate of successful hunt against these types of prey would be low. HLs do not pursue prey very far, and in fact, ants usually come to the HL, which is another convenience. Outside of an enclosed environment, I think you will find that HLs would not tend to pursue anything that far, and are not as suited to the agile task as other lizards, such as: spiny lizards, zebras, or whiptails. In the tank, you set up an unnaturally successful hunt.

Many people base their prey preference studies on several flawed premises. Off the top of my head, I can tell you that the desire of a Horned Lizard to chase down a cricket or anything else, probably has a lot to do with the fact that such prey is more rare for them. It's not surprising, and it also does not offer proof they should be feed crickets more often or as a substitute food.

Just because they chase it and seem to prefer it, does not establish that it should be a preferred prey item to offer over ants. A Horned Lizard would probably chase down and devour a fire fly too, which would be deadly...just as my dog would eat a case of Snicker's bars if left to his own decision! Therefore, to offer anecdotal prey preferences as a means to establishing preferred prey offerings, is flawed science the way I see most people conducting it.

It is my position, through my own research, that HLs derive certain nutrients from harvester ants, and that these ants are superior prey items for HLs for many reasons. This does not mean that HLs cannot survive without harvester ants, but it is my position that they are much better off with them, and that they are adapted by several physiological traits to capitalize on ants. Without them, they will not have optimal health, and though they will not die directly as a consequence of lack of ants, I am convinced that lack of ants is indirectly related to health problems which may cause untimely death.

Detoxification of the ant venom through digestion is no special feat. Many organisms can do this. In fact, snake venom can be ingested with no ill effect so long as you have no open wounds in the mouth or digestive tract. I have done it myself.

The resistance of Phrynosoma to Pogo venom by injection, is in my opinion more so a function of simplicity in biological responses when comparing reptiles to mammals. It is my opinion that Horned Lizards DID NOT evolve an immunity or ability to "detoxify" Pogo venom. Pogos instead adapted their venom to defend primarily against seed foraging mammals who steal their seed stores.

Reptiles, and the Horned Lizard in particular, just so happen to be less affected by the venom, due to their biological makeup. They are simpler creatures when it comes to nervous system, stimuli, and responses to everything from poison to radiation. In lab tests, Horned Lizards were not the only one's to display what could be perceived as a "resistance" to Pogo venom. The venom was also found to be over 200 times less effective against spiny lizards, than against mammals. LD50 for rodent was .12mg/kg, whereas for Sceloporus it was 28mg/kg.

Formic acid is the simplest carboxylic acid, is highly miscible, and easily metabolized. It is a natural antibiotic and building block of more complex protein chains. It is contained in harvester ants through uptake of plant matter in their diet, as formic acid is found commonly in plant matter as a direct result of photosynthesis of CO2. These are "harvester" ants after all, so presence of formic acid in harvester ants should not be such as stretch for so many people to accept, as I have seen. There seems to be a culture going around, of trying to discount the importance of formic acid or other ant constituents, and/or barring that, to question it's very presence in harvester ants, as if it's "magic".

It seems to be a trend amongst people who support alternative ( read non-ant ) diets.

Pogonomyrmex venom also contains phospholipases A2 and B, lipase, hyaluronidase, acid phosphatase.

While I feel that formic acid is an important constituent of harvester ants for antibiotic, antiparasitic, and cell repair; having carbon, hydrogen, and oxygen atoms in the chain also tends to lend consideration of formic acid as a free fatty acid. That would make it quite the source of lean fuel for a Horned Lizard.

Other important sources of lean fuel are also derived from the plant based ( primarily seed ) diet of the harvester ants. Albuminoid storage proteins from seed matter provide a great deal of energy at low metabolic cost.

"Storage proteins are large molecular-weight proteins associated with metamorphosis and reproduction in numerous insect species" (Telfer and Kunkel 1991; Wheeler and Martinez 1995; Seo et al. 1998; Pan and Telfer 1999, 2001).

Sounds pretty nutritious to me if it's that important to ants.

To answer the specific question of the original poster, carpenter ants do not sting, though they have a poison gland in the gaster, which contains formic acid.

Ant bodies are largely undigested because the Horned Lizard is efficient the way it is, and only digests what it needs, by washing the miscible nutrient components from the soft gaster of the ant ( where the nutrients are ), without the need to digest the bodies.

Crickets are largely digested in the process, but this does not mean that digestion is more efficient or healthy. People do not understand this, and too often mistake that just because the cricket is "more" digested, it must be "better". This is incorrect.

When fed ants, the HL passes them before the process of breakdown on chitin really starts. With crickets, that digestive process is slowed and the chitin is broken down. Chitin is a polysaccharide, and essentially considered as a sugar upon metabolism. It slows digestion, and the cricket has a much higher unhealthy triglyceride content to be used as a frequent feeder for HLs, unless you want an early death from fatty liver disease or pancreatitis ( hypertriglyceridemia ).

In summary, the importance of harvester ants, and their nutrients, is neither magic nor mystery; and neither can simple prey preference tests alone establish that other more convenient items are better offerings for Horned Lizards than their natural staple prey item- harvester ants.





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Wichita Falls Reptile Rescue
Harvester Ants

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