Reptile & Amphibian Forums

Hello All,

I am a Wilderness Firefighter in New Mexico and an avid herp keeper. When on assignment 3 months ago I brought home 3 SHL's. Following the basics of herp keeping I set them up with a spare 55 gal and set up over head heating on one side for thermoregulating. I filled the bottom with about 6 inches of decomposed granite that I use for my monitors, threw in some cholla skeletons and planted a group of cactus. Once I started researching these guys specific needs I realized that for the most part I had the basic setup ok. They have a basking spot of 94 degrees via tempgun and ambient warm end of 85 the cool end is 78. At night temps drop to 72. The few things I have not provided in the last three months but seem to be so important, according to the select few HL gurus is Ants and UVB. Sure they get the occasional ant that I scoop up in the yard but ants make up maybe 10% of their diet. I have fed them dusted roaches and crickets regulary and they took to them with gusto.

Has anyone done any long term studies on a diet not made up of primarily ants. It it only conjecture that they NEED ants to thrive? What results have you seen of a diet lacking in ants? How long was the specimen lacking an ant dominat diet. I guess my question is about WHY. Why do they need ants?

Most monitor species diets in the wild are not rodent based. They are made up mostly of large inverts, eggs, baby birds and then rodents. Successful Monitor keepers do not say, "well they primarily eat inverts in the wild so we HAVE to feed them inverts?" The most successful breeders of monitors in this country have bred using a rodent based diet.

It seems to me that just because a few scientists cut open the stomachs of HL's and found that ants made up the highest percentage of food everybody thinks they need them to be healthy. Ants can be found in huge numbers. Sit by an anthill and the lizard can gorge itself. I believe that it's an easy source and that HL's are oppurtunistic eaters, not that they need said insect.

UVB. Wow, all I have to do is spend a few moments researching and I can find controversy like mad about this topic. For one, most herps assumed to need uvb are not carnivores or insectivores they are folivores or otherwise herbivorous. reasoning is they do not receive D3 directly from the food. HL's are insectivores and I do not understand why they would need UVB.

I dust my crickets and roaches with calcium powder that contains D3 and no phosphorus. I do not provide UVB and have not seen any of the issues that I witness with green iguans that lack UVB.

I know I have only been a keeper of HL's for a short time I don't have much to go on. But my HL's have grown at least 2 inches in that time and are very active voracious eaters. According to the advanced keepers I am doing things wrong.

When I sit in my living room bored by the TV and look over at my HL's so plump and healthy, tromping so purposefully over the cholla obstacle in their way it makes me wonder how I can be doing something wrong. I know what the main HL site says about husbandry and what the gurus here at kingsnake say. I'd love to hear why they say it.

Nate

I, for one, would love to see a photo of your little critters. They're adorable aren't they? I don't have the answers to your questions, I'll leave that for one of those more experienced. But I WILL say that mine were fat and happy too and then suddenly stopped eating and got skinny. It can change on a dime and it will leave you scratching your head REALLY wondering "why??". It's hard to understand why they usually don't survive in captivity. I don't get it either.

Good Luck with yours and hope they live a long and happy life!

Post a pic if you can!!

Sorry I don't have a digital camera to post pics with. That is something definitely on my list of wants though.

Yes they are cute especially with their grumpy little faces.

How long did you have your HL's and what was their diet comprised of? Did you use UVB? Any idea what went wrong?

Nate

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.

You know . . .I really have no idea what went wrong. They were doing great. Got noticably fat and happy during the first few months that I had them ~ very healthy and active. Then they just stopped eating. Don't know why. Nothing really changed except I put them into a much bigger cage (which wouldn't really cause them to stop eating). I'm still trying to figure it out. They were ADORABLE!!!!!

Their diet was mainly crickets and about 20 or so ants a day (depending on how many they'd eat). I also gave a few small mealworms but not many. I also threw in a few other "bugs" I could find in the yard (beetles, etc).

I didn't have a UVB light but took them outside for 20-30 minutes every day to get direct sunlight. I was told 20 minutes of direct sunlight was more effective than an entire day of a UVB lamp. In addition, they were just "happier" when they could be outside. So I boxed in 3 sides and sat on the 4th side and let them roam around in the sun. I do agree that they need the UVB rays whether you give them the direct sunlight or use the lamp. Eventually, it will take its toll.

I had them for several months. They lost about half their body weight in just a couple of weeks of not eating. The particular species I had are particulary difficult to keep in captivity. When I saw how much weight they lost so quicly I turned them over to someone who keeps his HL outside (to hopefully live longer than I think they would have with me). He also just has so much more experience than I do and I wanted them to have a chance at living. Don't know if they are still alive or not and to be honest . . .I really don't want to know. Too hard. Sometimes, ignorance really is bliss. I prefer to think of them when they were fat and happy then to think they died. Be careful . . .these guys are easy to become attached to!! (They'll mean more to you than you will to them!) lol

To be honest . . .these guys are so difficult to keep alive that I think the best chance you have is to follow the advice people give you to the "T". Once in awhile someone does it "all wrong" and their lizard seems to live a long time. But that's rare. Usually, their HL will pay the price with their life.

It's not easy providing ants unless you order Harvester ants if they'll eat them (mine wouldn't). Otherwise, catching them is your best bet. I used a bug vacuum because I'm not skilled enough to use other methods! lol

I wish the best for your little guy, Man . . . it's not easy but they're definitely worth the effort. Hope yours lives a long and happy lizard life!!! lol Too bad about the camera. Would love to have seen a photo.

Nate you seem a littel authoritive with your challenge, you can do what ever you want and if that works I am happy for you. Please take some time to read our web-site at Phrynosma.com. You will find the results of some studys on horned lizards and a table that sets out more or less what has been discovered about the eating requirements of horned lizards. all horned lizards eat ants as a staple, not because it's easy to get, some horned lizards not fed ants will die because of the amino acids in the ants that are necessary for good health. It is a fact that some short horns eat less ants. This may be true with yours, however if I was you I would consider getting a "bugnapper" or at least vary the diet more than just two insects. Alos there have been horned lizards that have died due to poorly run cricket farms passing on disease. So I never make a habit of making crickets a staple, also mini mealworms are good, and was worms. Also you may try the small snails that are indigious to your area, as they will eat them as well. SO many people have spent more hours than you can think of observinbg horned lizards in the field in their natural envirionment, and while they do eat bees and grasshoppers and various beetles they as a whole seem to go for ants. ANother thing you might do is if your out in the field and can find scat, break it open and see whats in it. Scat anaylysis again shows that horned lizards ususally and often prefer ants as one of their "mainstay" food items. O.k.?

The UVB is part of the suns spectrum, and thousands of lizard breeders with thousands of hours of experience and investment as a general rule use either a flourescent or a mercury vapor. I use 7% UVB Desert bulb as standard fair for my inside lizards. LIke humans not being exposed to UVB can seriously affect lizards. SO Nate if you think all the people that have had serious study as thier jobs and thesis etc. are wrong please give me a compeling reason why we are all wrong? The burden of proof is on you not me for that one. Sounds like you have the basking set up properly, and I assume the cage from your description sounds good. Do you feed your horned lizards with a water dropper, spray the cage, or have a water bowl. These lizards are known to take in more water than others, and usually found in a damper cooler climate. I have captured these up in Rioduso as they are very common up there. Anyway I challenge you to read the site and take in the info as much as you can, and this site is not the meanderings of a few peoples opinins, but represents information across the board to help people with real husbandry issues. There is a committment to taking care of these while D3 is helpful, what would be better is if it's still warm, exposing them to real sunlight for an hour a day if you not going to use a UVB bulb. I think you may not understand the importance based on you research of complaints and differing opinions about the subject. What happens is the lizards look nice and fat and healthy but their arms and hands begin to become rubbery. While I have not worked extensively with short horns, most of the people I know that have them do use a bulb or keep them ouitside. I don't think there is much more that I could say to convince you that to have a long relationship with your lizards, the UVB one way or another is something you should consider. I leave it up to your own "research" to determine you are doing everything that needs to be done, because they are nice and fat.....Cheers I am happy for you, and by the way, I am not a GURU of horned lizards but have studied them since 1972 and have kept many different species and know a lot of people that have them and are successfully taking care of these and breeding them, and I believe the information "I" have given you is accurate and is the accepted methodology,,,I hope this answers your questions. Cheers!!!
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Phrynosoma.com

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Reptoman . . . . I don't think I've seen you quite this feisty before! Kinda cute!! lol (Even though I KNOW it's because you feel so strongly about it.)

Nate,

2 inches in 3 months is quite impressive I haven't heard of a growth rate that fast, so keep on doing what your doing. The longest published record for a HL staying alive on a diet with no ants is 2 years (Wade Sherbrooke, 1987 Captive Phrynosoma solare raised without ants or hibernation - Herptological Review 18(1). Ants are probably not a requirement, just convienient. HLs have adapted to eat numerous small prey items and fair much better on appropiate sized prey. Many HL species will be noticibly sick the day after eating a bunch of large crickets or mealworms.They will refuse food for a couple days and decline in weight. P.asio, P.hernandesi are a couple exceptions, ants make up a small part of their natural diet with large grasshoppers and beatles making up the majority. My P. asio can eat large prey and not become sick but the same can't be said for P. platyrhinos.

3 months is way too short to see the negative effects of having no UV lighting. Many studies have shown UV lighting is required for calcium to be utilized. Powdered D3 didn't work. Signs of calcium deficiency takes years. It is most notecible in offspring produced by calcium deficient females. You would change your mind if you saw your SHLs limping around on soft limbs. My observations on short term effects conclude UV lighting increases activity, induces more natural behavior, and increases sexual activity during the mating season. After 15 minutes in the sun a healthy sexually active male will be chasing anything that moves.

Jeff as stated before I am going to have to take a little different perspective on ants in horned lizards. And while I was plain about short horns and the food items they take, if you look at the scat of short horns they have ants in them, and it is my opinion a healthy horned lizard is one that is fed ants, while some don't need a full regimum every day all the time, others are much better with and of the ones I have kept over the years best sucess is including ants, so while this person is sure of this for himself, I believe there is enough stuff on our own site to warrant that ants are a requirement. If you look at the posts below, people are providing the wrong husbandry and HL's are dieing, I am going to stick with what I said, not because that was "my" statement, but because of my own experience, as well as looking at the scats of these. When I was up in Riudoso I captures several Short horns and let them go, I was able to examine the ants in the area(Black Ants) as well as the scat. THe scat in these lizards during the summer were mixed with ants and beetles and other small insects. Hydration is another issue in these as well. Obviosly if he is having this much success this is admirable, but over the long run without proper lighting and in my opinion ants at least on occassion with respect to this specie. And the person above that said ants in horned lizard diets is contreversial, I don't agree to that either, on what basis does that come from? So much study by many of our experts and written material more than adequately have described the ant in scat analysis etc. While I know we are not going to agree on everything, my own personal experience and sucess with the species I have worked with causes me to take a little harder line, I have seen to many horned lizards that have not been feed properly nor proper husbandry and thats a shame. If we indeed have established that horned lizards eat ants and many as a mainstay in there diet what is there to contest here? I don't understand.
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Phrynosoma.com

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Thank you for all your replies. I apologize if my post appeared authoritative. I am not trying to suggest that I know anything about these animals besides what has worked for me for what I already explained a short period of time.

I simply wanted to know if what is currently "known" about HL husbandry was only based on study of wild specimens. a couple of you challenged me to read what other scientists have found studying them in the wild, or even doing it myself. I do not doubt that in the wild these animals are by the percentages, Ant eaters. I've seen figures as high as 85% and as low as 35%. What I am asking is has anyone seen HL's that were set up otherwise correctly despite a predominatly ant diet, and those animals not thrive? Despite the fact that I don't feed predominatly ants, I believe the average person that comes on here with a HL and doesn't feed ants, probably has other husbandry concerns.

It seems your reasoning for feeding ants is because it's what they do in the wild, not because you've seen them die or not thrive on a non-ant diet in captivity. I mentioned the monitors in the first post. When wild diets were extensively studied they have found that Rodents are only an occasional food item for the bulk of all monitors. Yet the most successful keepers in Europe and one of the most successful monitor breeders of all time here in the states uses a predominate rodent diet. This is the reason I was questioning the ant diet. Is it because they do it in the wild? Or because it doesn't work in captivity.

As for UVB I'm not vehemently against it's use. I do believe that in any case UVB is probably never bad, except maybe nocturnals. Something I have not seen though is ill effects resulting in true insectivores from lack of it. People have claimed, "well what about beardies?" and well they're not true insectivores. This rubbery leg issue you have seen, MBD? 3 months not enough time to show effects of MBD or other calcium deficiency issues? I have seen iguanas with full unflitered sun exposure, and supplemental UVB lighting with a strict diet of greens at a 2:1 Calcium to phosphorus and then end up in the wrong hands and in as short as 4 months see the same animal again with a grossly deformed jaw and bow legged. Obviously these symptoms started before the 4 months. But possibly this is an extreme case.

The UVB I realize is something I should probably be doing, and since I really like these little guys will be getting them a bulb soon. How do you feel about the powersun mercury?

Oh yes I almost forgot...the water issue. I started by spraying down one side of the cage and found that these guys love water. I love to watch them stick their butts up in the air and lap up the water. I spray them down once a day but always make sure there is enough time for the lamps to dry it out before they get turned off. I also prodvide a shallow water dish but they do not seem interested in it so I keep spraying.

I really appreciate the good posts and they are definitely making me think. I hope everyone realizes I'm not trying to be antagonistic, nor really challenging current husbandry. If I can know why the current husbandry practices are used then I believe I can better understand my charges and provide better care.

Thanks,
Nate

How could I have down any research at all without the only informative page on the net about HL's. Yes I have read through
phrynosoma.com Thank you to the people who put that site together. I've never seen a site so well put together about any species.

Nate

Nate, I have no formal study info regarding diet that I can point to about ants currently. But to compare different types of mammalian diet with different insect diets may not be the best way to go. Ants certainly have a far different chemical makeup than probably most other insects. Which would explain why other opportunistic reptiles in the same habitat will have little or no ants in their scat vs an HL, which will have primarily ants depending on species of course. Also, there have been quotes from field observations about HL scat being primarily beetles in some habitat, which would seem to lend credence to ants not being required. I have had a chance to observe several species in the wild over time and have found scat is primarily ants, but at certain times of year can be primarily beetles or what have you. I think this type of thing is very seasonal and that the ants remain the primary choice for most of the year, but this is based on non-scientific observation. Could be an interesting study in itself.
I also wanted to say thanks for the web site compliment and for your very healthy attitude in looking into your HL husbandry requirements.

Cheers!
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Phrynosoma.Com

NAte-with respect to water, often you can get them to actually drink from a small dropper, you migh try it, hydration seems to be an important issue ion these. Also my last comment on the horned lizards--someone on the forum reminded me that SHL's usually need between 15-30 percent ants in their diet, this is lower than many others, but here is the issue, if yo had an animal that feeds on a certian variety of insects, and due to good scat anylisis this is a known fact, why would you in the interest of the reptile deviate and experiment with not including an important part pof the lizards health and wellfare by feeding it ants. Are the ants in your area the black ants? These are the ones I have found the shls in Ruidoso eating. I have heard of people raising some species of Hl's with no ants, I hope in the interest of your lizards you consider feeding them ants as part of their regimium. Please do get the UVB lighting for your guys, just a little more expense and you'll have a good set up going. You might consier a 7% UVB flourescent bulb, or a mercury vapor bulb maybe a 100watt since these lizards do not need the high temps that others require. I would in a 55 gallon cage keep a 100watt mercury vapor and a 75 watt flood just down from that mercury vapor JUst slightly before the middle to produce a hot end, if that makes the heat more than the lower 90's then maybe change the flood to a 50 watt. This would or should give you a good gradiant for the lizards to thermoregulate. If you use a flourescent you'll need to have a basking bulb as well, I think the mercury vapor is the cheapest and best way to go....Cheers!
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Phrynosoma.com

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This is really a great debate. I think the best way to settle it would be to attempt some longer range studies.
In my experience ants have been integral to solid health, but I have talked to quite a few folks that have been able to keep HL's alive fairly long term without them. I have not heard yet of anyone who has had any HL's on a non-ant diet long term that has had breeding success, which to me is a sign of optimum health. That said, this is probably a species specific requirement to whatever degree. So results are sure to vary. I believe sunlight is also very key and may rank in importance with a proper diet.

It seems there are a few folks out there who are having breeding success and it would really be great to get your input for phrynosoma.com. (please contact me via email if you have an interest in adding to the site information at all ) To truly assess the diet requirement we really have to go by the facts we can find (literature) or observe. So that said, I would like to offer a challenge in the form of a formal study over at least a 2 year period (3 would be better) to see what growth rates are and breeding success on various diets, for the species of HL's that are being bred successfully, keeping all other factors even.
I would be happy to coordinate the study guidelines, etc... (and welcome any help from all with an interest)
Any takers?
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Phrynosoma.Com

Hello Nate.
I've heard alot of stories of people keeping horned lizards without ants. There was a paper written several years ago by Richard Montanucci. He suggested offering the horned lizards vinegar in the absence of ants. HLs seem to be succeptable to intestinal infections and the acidity helps to combat it. You can spray vinegar on the crickets or small superworms before feeding them to the lizards. Wild caight horned lizards often do well for a few months and then start declining. It might be because they are often carrying parasites so it seems that worming them would be a good idea too.
As far as UVb goes I can't say for sure. I have some 2 month old captive hatched platyrhinos that have at least tripled in size without any UV lighting, just Reptocal vitamins. I don't think they need it for calcium metabolism but I do think that UV has an invigorating affect on them. It would probably enhance breeding success, especially UVA. I breed alot of collared lizards without any UV but I haven't seriously tried to breed HLs yet.
One more thing before I quit rambling. I think that feeding the insects a wide variety of fruits and vegetables is important. I don't know if there is anything to this but I've heard people recomend feeding the crickets limes and bananas.
Good luck with yours.
Paul

Hey Paul,
Could you share the title of that Montanucci paper? Was it just a suggestion or part of an actual study?

I have heard it is an acid they need, but it would seem (and hopefully Gordon can comment) that Pogonomyrmex (many HL's main diet) do not have acids to any significant degree. The sting components are proteins which the HL has adapted to and can neutralize with it's own blood components. The lack of these proteins in the diet I hear are what build up in the HL when ants are not fed and MAY be the cause of health decline.
More info is needed here for sure.
Thanks
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Phrynosoma.Com

It was Bulletin of the Chicago Herpetological Society volume 24, Number 12 December 1989. That was quite a few years ago so there may have been more studies since then. I could probably copy it and send it to you if you're interestd.
Paul

Thanks Paul,
I have this paper. The vinegar threw me. He didn't mention it specifically (unless I missed it). He talked about the possibility of acidifying water to improve health of ailing HL's. This is a bit of a stretch in saying it's a replacement for ants. But certainly interesting and worth consideration and possible study.
We are working up a study on diet both antless and with ants. Perhaps this can be incorporated.
Thanks again!
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Phrynosoma.Com

Hello Nate.

I always like it when this question is repeated over and over again. WHY do horned lizards require ants in their diets? I could simply answer "Because they do."

There are many animals that have very specific diets that cannot be supplemented or modified. The koalas of Australia require eucalyptus as the main staple for their diet, and not just any eucalyptus, but very specific species of eucalyptus. The Great Pandas of China have a very specific diet of bamboo for the main diet, and that too is very specific. The Thorny Devil of Australia has a very specific ant diet (100%) also.

Why do these specifics exist? The animals developed these diets because of evolutionary processes that insured their survival.

Ants are probably one of the most numerous insects on the planet. What better item could there be for a diet? Of course there are certain adaptations that will be required if your diet is to be a high percentage of ants. One adaptation is the need to detoxify ant venom, which can be deadly. Horned lizards have this adaptation in the form of a blood factor that detoxifies this venom and turns it into beneficial compounds like water and carbohydrates. The enzymes also provide a digestive system chemistry that maintains a specific acidic pH to control certain internal microflora. Another adaptation is the structure of the teeth. Horned lizard's teeth are designed to be the least intrusive when capturing ants. Horned lizards do not have a strong bite pressures for such things like chewing and grasping prey items.

I have disected many preserved horned lizards to analyze stomach content to study diet. I monitor several horned lizard study sites, and have done so for nearly 18 years and collected scat throughout the seasons to monitor exactly what horned lizards are eating, on a daily and monthly basis. Ants are a major dietary requirement.

I have raised captive bred horned lizards, from hatching to old age (9 years), and experimented with dietary variation. The best results are with 80 - 90% ants (19 different species of ants found through scat and stomach content analysis). Growth rates were comparable to wild hatchlings. Comparitive analysis with captive vs wild hatchlings through old age on dietary balance is 0.00113mm per day growth rate from hatching to 4 months. Variations of withholding ants from the diet had very negative results and high mortality.

Ants are a major part of the diet of many species of horned lizards. That is just a fact. Mother Nature's design has a reason. Any alteration will take time. if it is to be. If you want to keep horned lizards, ants are a necessity. If you cannot meet that requirement, as well as other specifics, leave the horned lizards in the wild and protect the habitats in situ.

Lester G. Milroy III
Conservation Biologist