What you feed your bearded dragon will have a massive impact on its long term health and well being. Unfortunately the exact nutritional requirements of bearded dragons are not known. On top of that, diets that have been established along the way are not necessarily keeping pace with the latest research. Its like humans sticking with diets recommended 2 decades ago, it was good for us then so it must still be good. We see vets with incredibly and frustratingly varied information on the subject, breeders, pet owners, we are all in the mix. A lot of information available on the internet does not reference any credible source and some of it has become a fact simply from being repeated enough times. In addition, when we refer to bearded dragons in the pet world it is with a wave of a very wide brush encompassing every lizard under the genus Pogona as if even though evolution saw fit to make them different, their needs must be exactly the same.
Bearded dragons have been kept as pets for long enough now to establish a reasonable idea of what is good and what is not but we clearly have a long way to go given the prevalence of nutritionally related disease. With the support of research on diets in the wild improvements can be made.
Research has shown us that juvenile bearded dragons start out life as insectivores (studies focused on Pogona barbata). Although the term insectivore is a bit of a poor label in that they eat from the arthropod range. The gut contents of the latest research in juveniles included Coleoptera and Orthoptera. Juveniles eat active prey including arthropods that fly and consume bigger prey than adults.1,3
We have been aware to date that adults are omnivores and perhaps the fact that juveniles are insectivores has penetrated some of the dietary guides out on the web. But the 2016 research by Wotherspoon and Shelley was able to drill down into that further finding evidence of differences in diet between females and males and even further differences within males based on size. Females fitted within the typically omnivore type of profile but ate prey that they could ‘sit and wait’ for (ants) unlike juveniles who actively pursue prey including flying arthropods. The males ate a large proportion of vegetation, with the larger the male the higher the proportion of vegetation to a point of being herbivores. None of the vegetation had been chewed and the main insect eaten by any adult was ants (unlike juveniles). In another study, the vegetation content of some adults was so high (90% or more) that it was suspected that the odd insects that were consumed (mostly ants) were picked up by accident1.
In respect of vegetation, dandelion and clover are the most commonly eaten vegetation in the wild despite being introduced species. Both these plants have soft and small leaves.3 Incidentally dandelions are very high in protein. Research by Ghaly et al (2012) found dandelions to contain 4.70% protein. As a guide, apples had 0.26% and sweet potato 2.57%. Would be fascinating to know if this somehow influences the bearded dragons preference to it.
An observation was made by Thompson and Thompson in 2003 when conducting research (the research was not focused on diet) on the Pogona minor minor in Western Australia that some had ants in their mouths and some were found to frequent ant mounds. Ants do seem to be a staple in the diets of bearded dragons regardless of which species.
In the research conducted by Wotherspoon and Shelley it was found that juveniles require a high protein diet which would support growth. Females need higher levels of protein and fatty acids than males for reproduction purposes. The larger the male the more herbivorous and it is suggested that this grazing type of behaviour suits the lifestyle of a male wandering around protecting its territory. Bit different to the four foot long housing so many are provided with.3
This could go at least part ways to explain why some people are successfully able to feed vegetation in large proportions and others just can’t. It would be worth noting if the apparent fussy eater is female or male and how it fits into the research on its wild counterparts.
Proportion of food groups
As adults bearded dragons are omnivores and should be fed mostly vegetation. For adults the proportions are recommended anywhere from 50-90% of vegetation with the remainder being insects. As seen earlier in the wild counterparts, the males are more likely candidates for a higher proportion of vegetation.
This is not the same for the young who require the majority of their diet to be in the arthropod family, typically insects. Juveniles do not need vegetation, they are still insectivores at this age. They do not become complete omnivores until pre-adulthood. Some vegetation is generally recommended for pet bearded dragons.
Be flexible on proportions of vegetation versus insects to some degree. Consider what diet it would likely be eating if it were in the wild given its age, sex, whether it is shedding, in brumation or gravid and the season. Add to that how it is interacting with its habitat. Is it expending energy interacting with its environment? Does it have far to move or just a few steps to a food dish or will it expend energy to eat (allowance for natural grazing/chasing food behaviour)?
Use foods from the recommended range and somewhere within the recommended proportions. Observe your bearded dragons changing needs whether from age, gender, season or any other influencing factor and work with it. Some allowance for its own personality will go a long way to reducing stress as well. Validating your bearded dragons health with your veterinarian and asking their opinion on the diet you are providing will give you more insight on how it is all going.
Nutritional value of selected insects
All insects have an array of nutrients not detailed in this list, such as linolenic acid in mealworms which reptiles have a small requirement for.
Top 10 plus foods with the highest water content
Foods Dangerous for your Bearded Dragons
Foods Dangerous for your Bearded Dragons
|Foods High in Fat||Foods high in fat impede calcium metabolism.|
|Acacia erioloba||Exceedingly high in Oxalates. Raw 476 mg/100g. All parts toxic. Known to have caused the death of human infants after consumption. May cause mutations and birth defects.|
|Acacia glaucescens||Accumulates nitrate. May rise to toxic levels dependent upon growing conditions. 'Very high' nitrates bracket.|
|Asparagus||Exceedingly high levels of Oxalates, boiled 675 mg/100g. Contains saponin considered toxic to ectotherms, levels unknown.|
|Avocado||All parts toxic. Do not feed. Contains persin. Seek veterinarian treatment immediately if consumed.|
|Bamboo Shoots||Contain high levels of cyanogenic glucosides, sweet varieties can contain up to 50 times less HCN than bitter with some as low as 20 mg per kg.|
|Beets raw and boiled (beetroot)||Contain saponins considered toxic for ectotherms, estimated 3.1-3.5 g/kg.|
|Beet Greens||Extremely high in oxalates with varieties differing from 777.1 to 1224.0 mg 100g.|
|Blue Couch (Cynodon)||Contains saponins considered toxic to ectotherms, 0.14-1.3 g/kg. Nitrate data unknown, however considered to be in the 'very low' bracket.|
|Broad Beans||Known to accumulate sufficient quantities of cyanogenic glycosides to resulting in poisoning of livestock.|
|Cassava (Yucca) root raw||Known to accumulate sufficient quantities of cyanogenic glycosides to resulting in poisoning of livestock.|
|Hollyhock (Althaea rosea) leaves and flowers||From the Nightshade family. Glycoalkaloid levels higher than that of tomatoes and aubergine. Contain caffeic acid and proteinase inhibitors.|
|Johnson grass (Sorghum halepense)||Contains saponins considered toxic to ectotherms, 0.14-1.3 g/kg. Nitrate data unknown, however considered to be in the 'very low' bracket.|
|Lambsquarters||From the Alliaceae family. Contains saponins which are considered toxic to ectotherms. Esimated 1.0 g/kg.|
|Leek||Known to accumulate sufficient quantities of cyanogenic glycosides to cause poisoning of livestock.|
|Native Couches (Brachyachne)||Risks of high oxalic acid (1.5 mg/g) and cyanogenic glycoside with young shoots being as high as 7700 mg HCN/kg. Cooking aids reduction. Processed and canned shoots are likely to have low to undetetable traces.|
|Okra||Known to accumulate sufficient quantities of cyanogenic glycosides to cause poisoning of livestock.|
|Orange||Citrus fruit are not recommended.|
|Pokeweed||High in Oxalates.|
|Potatoes||Known to accumulate sufficient quantities of cyanogenic glycosides to resulting in poisoning of livestock. Small portions may not cause issues, however not recommended.|
|Purslane||Oxalic acid levels extremely high. Some studies averaged leaves at the 16 leaf stage up to 45% lower than the younger 8 leaf stage. Phytates are exceedingly high (8.236 mg/g). Best not fed or fed with extreme caution.|
|Rhubarb||Exceedingly high levels of oxalate. Do not feed. Stewed 860.0 mg/100g. Canned 600mg/100g.|
|Sorghum spp.||Contains saponins considered toxic to ectotherms, 0.14-1.3 g/kg. Nitrate data unknown, however considered to be in the 'very low' bracket.|
|Soybean & products including Tofu||Soybeans contain saponins considered toxic to ectotherms, between 0.9-43 g/kg. High in phytates. Tofu is high in fat, approx 7% and 1.3 mg/g oxalates (very high). See research article link for further information on Soy from humans perspective. "...trypsin inhibition decreases with processing. The problem is that the methods used to remove or decrease the isoflavones can create troublesome side-effects for man..." Cambridge International Institute for Medical Science, The Physician's Concise Guide to Soy Fiction|
|Spinach||Exceedingly high levels of oxalates. High in nitrates, caution required. 5064 mg/kg leaves, 5910 mg/kg stalks.|
|Swiss Chard||Known to accumulate sufficient quantities of cyanogenic glycosides to resulting in poisoning of livestock.|
While research in reptile nutrition has a long way to go, there is certainly enough information on bearded dragon diet to support them into their 2nd decade of life. Nutritional disorders are very common and are not typically detected until symptoms become clinically apparent. Nutritional disorders may be caused by environmental factors such as small enclosure size, poor lighting, cohabitants and substrate or directly by food. All nutritional diseases are avoidable. The prevention of nutritional disorders is possible through understanding naturally available foods in the native environment, staying informed on scientific advances in nutrition and putting in practice good husbandry.
Excluding foods for various antinutritional factors is a necessary part of diet control, however goitrogens and oxalates are given so much attention that it results in other nutrients and antinutrients being ignored. In addition, studies have shown that some of these elements that have been labeled as antinutritional can also have positive effects.
Providing foods known to be high in an antinutrient (such as a cruciferous vegetables high in goitrogens 3or insect high in fat) is not out of the question, it must simply be balanced out with other vegetation. The best way to protect overdoing any antinutritional element is to stay within the bounds of foods that are generally considered safe and most of all to ensure variety.
Calcium to Phosphorus ratios and quantity
The need to balance calcium to phosphorus ratios in the bearded dragon diet is quite widely acknowledged and there are many lists of foods with the ratios available. However providing foods simply based off this ratio is inadequate to assess a foods suitability for inclusion in the diet and opens the risk of not providing a balanced diet.
The quantity of calcium is also of great importance, too high or too low has the potential to cause nutrition related diseases either way. There are also factors that can inhibit calcium absorption such as fat, vitamin D, oxalates and other nutrients or antinutrients.
Insects do not generally have reasonable levels of calcium and their calcium to phosphorus ratio is typically negative. For the young bearded dragon, which require primarily insects, this places them at higher risk of not being provided sufficient calcium or perhaps to exceed levels as dusting with calcium can just as easily be overdone as underdone. However, to support the animal during this growing phase dusting and gut-loading insects is necessary. For the older bearded dragon that is consuming vegetation, supplementation may be reduced where it provides sufficient levels, bearing in mind inhibitors of calcium absorption.
Calculating the nutrient quantity and ratios
The example of foods to feed your bearded dragon below is based on an adult with a diet of roughly 50% leaf, 20% vegetable, 20% fruit and 10% insects. The total weight of the diet should generally be around 10% of a bearded dragon with an average body score.
Note that not all nutrients or antinutrients are provided in the example below.
|Food Item||Serving||Weight||Ca (mg)||P (mg)||Protein (g)||Linoleic
|Blackberry raw||1/8 cup||18.81||6.35||3.57||0.21||1.17|
|Capsicum green||1/8 cup||18.62||2.18||4.41||0.16||0.32|
|Endive raw||1/4 cup||12.50||6.00||5.94||0.16||0.33|
|Kale leaves raw||1/4 cup||16.75||29.73||12.90||0.59||0.44|
|Turnip greens raw||1/4 cup||13.75||19.80||5.98||0.21||0.58|
|All Items||1 cup +
|88.69 g||65.31 mg||52.77 mg||2.23 g||0.04 mg|
The meal above totals one cup of vegetation plus 14 feeder insects (mealworm adults data based on fasted) and comes to a total of 88.70 grams. For a bearded dragon that weighs 500 grams this would equate 17.7% of its body weight which is excessive. However 10% is a generalisation, fruits and vegetables weigh more than greens due to the bulk for the same space, preparation (i.e. chop, puree, sliced) also makes a difference in weight per serving and there will be periods in life where more food is required than other times.
The calcium to phosphorus ratio of the above meal slightly exceeds one to one which on the surface appears to be adequate. However the total calcium should be around 1.5% of an ideal meal, this diet is only 0.74% and phosphorus around 0.75%, this diet being 0.59%, so even though the calcium ratio may be adequate, the total calcium is not. In addition this diet has also included 29.37 grams of oxalates, 16.87 mg of glucosinolates and 0.53 grams of fat; two of which have the ability to inhibit calcium absorption. Discussions on oxalates are rife and many foods are excluded because of it, however it is not as simple as whether a food has oxalates and trying to eliminate foods with any such antinutrient is not only impossible but ignores the beneficial nutrients that are also available. Each plant will typically have insoluble and soluble oxalates. In addition, the tolerance levels of oxalates in the bearded dragons diet are not known, therefore we use ‘guesstimates’ based on human diets.
Dusting with calcium powder a few times a week will bring the calcium levels up, but even dusting has its issues. The calcium particles do not easily adhere to most insects and if the insect is not eaten immediately the calcium can be groomed off, or simply fall off, the insects body as time passes. To combat this feeder insects should be gut loaded and dusted. Silkworms simply require their standard meal of mulberry leaves, but other insects should be fed specifically targeted nutrients. The combination of gut loading and dusting will improve their nutrient levels and means vegetation does not need to be dusted, this is important especially for those fussy eaters who will quickly tire of the unpleasant taste which will generally tolerate it on insects.
Can Bearded Dragons eat Eggs?
Providing any food in the bearded dragon diet comes down to the assessment of why, what are the benefits and potential harm. When it comes to hen eggs most will point to protein being the reason to feed them, yet insects generally provide far more protein. A mealworm adult can provide 0.237 mg/g protein, or an adult cricket 0.250 mg/g protein, yet eggs provide only 0.125 mg/g protein. The protein requirement for bearded dragons in their second year as they become omnivores is far less than that of the young.
Eggs of any fowl has not been recorded in a bearded dragons natural diet in the wild. Whilst it is obvious that the bearded dragon diet natural is replaced in captivity providing something more akin to what nature gives them is less likely to introduce health issues later down the track.
Regardless, at this point we cannot even claim hen eggs are good for humans let alone our pets. For the human perspective, which has some relevance, check out M.D. Michael Greger (Physician, author and professional speaker reviews and discusses the world’s nutrition research) at NutritionFacts.org.