Nate:



You bring up a number of valid points in your post. The question of whether ants are a necessity in the diet of captive horned lizards is certainly controversial. I know of at least one person who has raised hundreds of horned lizards without including ants in the diet. Also, as you mentioned, many captive diets are not representative of what reptiles and amphibians are eating in the wild. However, in my experience at a veterinary clinic, I have seen a number of animals that come in with kidney failure and fatty livers, problems which are most likely related to poor captive diets. For instance, bearded dragons and Uromastyx which receive no greens, iguanas which receive too much protein, etc. These problems lead me to believe that many of the problems people experience with horned lizards are in fact related to improper diet (ie. improper calciumhosphorous ratios, high exoskeleton:meat ratios of cultured food items, etc). The idea that formic acid is a necessity in the horned lizard diet is also interesting. Gut flora is likely completely changed or killed when these animals come into captivity and experience a 180 degree dietary change, leading to bacterial infections (see Montanucci, Bulletin of the Chicago Herp. Society, Dec. 1989), another factor which could be responsible for the typical demise seen in captive Phrynosoma. What I personally feel is the biggest problem with captive horned lizards is that cultured food items are just too damn hard to catch for these guys. The delicate tongue morphology (which has evolved to capture almost strictly ants in the wild) is perhaps damaged in these animals' attempts to chase down crickets, causing pain and lack of appetite. This compounded with factors above is what makes feeding ants (or at least ant-like critters) mandatory for captive horned lizards. I feed mine P. californicus (easily mail-ordered and inexpensive), mini mealworms, termites, crickets with their hind legs removed, terrestrial isopods, flour beetles, etc. I have also started five captive ant colonies this year (it looks like only three will be successful) in order to supplement my animals with different varieties of ants.

As to your questions surrounding UVB... I always provide my lizards with both a flourescent UVB source and an incandescent UVA/heat source. This is just because this is what these animals receive in the wild, and I feel it is important to try to provide captive animals with conditions similar to those in which they live in the wild. And there certainly is research in support of UVB for insectivores, and I prefer to avoid possible problems (ie. calcium deficiency and other uncorrectable maladies).

Keep in mind, these are just practices which I have culled from keepers at phrynosoma.com, biologists, and my own personal experiences, and I am in no way an expert.

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