A great resource on reptile husbandry is Reptfiles. We reached out to the author of Retifiles.com, Mariah Healey, to see if she would be willing to help contribute to our blog "Ask the Reptile Experts". Mariah was very gracious and willing to contribute on two topics, blue tongue skinks and reptile nutrition. Below is a brief bio on Mariah and her expert insights on reptile nutrition.
Author: Mariah Healey
Experience – Qualifications: I am the author and head researcher at ReptiFiles.com, an educational website where pet reptile owners can access comprehensive, species-specific, and correct reptile care guides for free. ReptiFiles currently boasts 14 different care guides, but that number is constantly growing! I am also a reptile husbandry consultant, in which I offer a variety of services to help prospective, new, and more experienced reptile owners take better care of their pets.
Brief bio: My career as a reptile educator didn’t start until early 2015, but I’ve been interested in reptiles and animal research since early childhood. When I was about 4, my pediatrician was a friend of the family, and we visited her home often. Her house was better than a zoo—dogs, turtles, and an African lungfish named Louie, among other things. But my favorite was their sandfish skink. His name was Wink, and my most vivid memories of him are of my pediatrician poking the sand with a pencil to make Wink jump out of the sand to “say hi.” Since then I have had direct experience with many different species, including bearded dragons, blue tongue skinks, red-eared slider turtles, Argentine tegus, crested geckos, ball pythons, boa constrictors, and others.
Facebook Link: https://www.facebook.com/reptifiles/
Reptile Care Focus: Nutrition
Why is this topic so important to you?
I’ve always had an interest in human nutrition, so naturally, this interest has manifested in my reptile care research. I believe that the correct diet can solve a lot (but not all) of the problems that we encounter in captive reptiles, most notably obesity.
What is the most important aspect of this topic the average reptile owner doesn’t understand?
Reptile nutrition is complex, and there’s no one-size-fits-all solution. In fact, nutrition can be one of the most difficult aspects of having a pet reptile, and failure to meet their unique nutrition needs is one of the biggest reasons why many pet reptiles die each year.
Most pre-made reptile diets that you find in pet stores are insufficient for meeting the complex nutritional needs that reptiles have, and this is counterintuitive for many people who have grown up with the assumption that the pet store is the place where you go to buy pet food. Dog food for dogs, cat food for cats, hamster food for hamsters, etc. But reptiles are an incredibly diverse group of animals. They’re not like different breeds of dog that can all eat the same food. What’s the difference?
- Breeds are different varieties of domestic animals that may look different, but at the end of the day, they are still the same species. For example, German Shepherds look very different from Pomeranians, but they have similar genetics because they’re still both dogs.
- Species are genetically separate animals that may or may not belong to the same genus. For example, pet dogs (Canis lupus) and coyotes (Canis latrans) are different species that both belong to the same genus, Canis.
- Genus (or genera in plural) refers to a group of different species that are closely related enough to breed with one another. However, an animal from one genus can’t breed with an animal from a different genus. For example, housecats are Felis domesticus, while dogs are Canis lupus.
- Subspecies is a subclassification of species. For example, an Alaskan Malamute might look like a fluffy breed of Gray Wolf, but they’re different subspecies. Pet dogs are Canis lupus domesticus, while gray wolves are Canis lupus lupus.
Most of the different reptiles available in the pet trade are entirely different species that usually belong to different genera. A green iguana (Iguana iguana) and a leopard gecko (Eublepharis macularius) are as different from one another as a dog from a cow! Would you feed hay to a dog? Of course not — the dog would die of malnutrition. The same goes for reptiles. Feeding kale to a leopard gecko or crickets to an iguana would have the same result. This is because green iguanas are herbivores while leopard geckos are insectivores. They need different diets in order to get the right nutrition.
Herbivores? Insectivores? That’s right. As part of a healthy ecosystem, all animals (not just reptiles) eat different kinds of food. This helps make sure that there’s enough food to go around, even when there are hundreds of animals in a relatively small area:
- Frugivores eat primarily fruit.
- Herbivores eat primarily vegetables, with some fruit.
- Insectivores eat primarily bugs.
- Carnivores eat primarily meat, usually whole animals.
- Omnivores eat everything — fruit, vegetables, bugs, meat, etc. For example, humans are omnivores.
But just knowing what type of food your particular species of reptile eats isn’t always enough. If you have an omnivore, then you need to provide the right ratio and type of protein to vegetation. For example, bearded dragons (Pogona vitticeps) and blue tongue skinks (Tiliqua spp.) are both omnivores, but they need completely different ratios of the foods in their diet in order to be healthy:
- Adult bearded dragons need about 15-20% insect protein and 80-85% vegetables. This can be accomplished by offering salad every day and feeding insects 1-2x/week.
- Adult blue tongue skinks need about 50-60% animal protein (whole animals and insects) and 40-50% vegetables. This can be accomplished by using raw dog food mixed with fresh vegetables, offered 1-2x/week.
Although they are both technically omnivores, the nutritional needs of bearded dragons and blue tongue skinks are significantly different. If you fed blue tongue skink food to a bearded dragon, the bearded dragon would likely develop kidney disease and/or obesity due to a high protein diet. If you fed bearded dragon food to a blue tongue skink, the skink would become emaciated due to a low protein diet.
Another common problem I see too often with pet reptile nutrition: Lack of variety in the diet. How would you like it if you ate the same breakfast, lunch, and dinner every day? Aside from getting boring really fast, this is also a fast track to malnutrition. When you eat the same thing every day, you get too much of some vitamins while missing out on others. This is what we do to our reptiles when we feed them the same collard greens and crickets every week, or the same flavor of crested gecko diet, or the same size and type of feeder rodent.
Aside from preventing vitamin deficiency, dietary variety also helps stimulate appetite. Pet reptiles who eat the same thing for years can lose interest in food because it looks and tastes the same, and their instincts naturally tell them to take interest in and eat a variety of things.
Snakes (carnivorous) and insectivores are a bit of an exception in this case, as they are opportunistic hunters that will take whatever comes their way first. That is not, however, an excuse for not providing a variety, as the risk of vitamin deficiency is still present.
Finally, we need to correct the way we view and dose reptile supplements. I’ve seen too many paranoid, ill-informed bearded dragon owners who make all of their dragon’s food look like a winter wonderland because it’s all coated in a thick layer of calcium powder. Or people who use calcium supplements with D3 religiously, even though they’re using a UVB light. Or snakes that have developed Metabolic Bone Disease because the rodents they were fed didn’t have enough vitamin D, and the snake didn’t receive any supplements at all. Or reptile owners who grab the first reptile supplement on the shelf just because it says “calcium” or “vitamins” on the label. Proper supplementation is a delicate balance that depends on what you’re feeding your reptile, how often, how old, and whether or not UVB is being used. For more information, read ReptiFiles’ blog posts on the subject: What You Need to Know About Reptile Vitamins and Feeder Insect Nutrition Facts for Reptile Keepers.
Along those same lines, we need to be more diligent about the way we gut-load our reptile’s feeder insects and rodents. “You are what you eat,” they say, and this saying holds as true with pet reptiles as it does with humans. What’s gut-loading? Gut-loading is what you feed to your reptile’s food, and when done correctly, gut-loading can greatly increase the amount of nutrition that your pet reptile gets from eating that bug or rodent.
It’s too easy to buy some cricket food powder and some water crystals and call your feeder insects “gut-loaded.” Gut-loading is about more than filling bugs’ bellies. It’s about providing better nutrition in the end for your pet reptile. The insects that reptiles eat in the wild are not munching on animal carcasses or piles of grain — they’re eating leaves, grass, fruit, flowers, etc. Grains are fillers that provide little nutritive value. And when you feed your feeder insects dog food, you can skyrocket their protein content to dangerous levels. Instead, use fresh vegetables, dampened alfalfa pellets, vegetable powders, bee pollen, and high-quality, low-protein commercial gut-load powders.
Rodent gut-loading is more difficult to do as a reptile owner unless you breed your own feeder rodents. The key here is to buy the highest-quality feeder rodents you can find. Ask the breeder what they feed their stock. What conditions are they kept in? Do they get lots of exercise? Are their cages cleaned often? Do they have access to plenty of fresh water? All of these factors come together to raise healthy feeder animals, and your feeders are healthy, your reptile will be healthy as well. You may have to pay a bit more for higher quality feeders, but I promise you, it’s worth it.
Are there products or setup requirements that would help address this topic or products or setups to avoid?
- My favorite ready-made insect gutloads: Arcadia InsectFuel, Repashy Grassland Grazer, Vit-ALL
- My favorite calcium powders: Arcadia CalciumPro Mg, Miner-ALL, Repashy Supercal
- My favorite reptile multivitamins: Arcadia EarthPro A, Repashy Supervite
- My favorite feeder rodent breeders: Layne Labs, Rodent Pro
- My favorite meal replacements: Arcadia OmniGold & InsectiGold, Repashy Grub Pie, Reptilinks
- My favorite frugivore diets: Pangea, Repashy, BP Zoological, Arcadia StickyFoot Gold, Leapin’ Leachies
Final thoughts on the topic?
I think I’ve gone on long enough, haha.
Links you would like to share for more information or research?
- Beautiful Dragons’ Nutrition Database
- What You Need to Know About Reptile Vitamins
- Feeder Insect Nutrition Facts for Reptile Keepers
- AHH Enriched Husbandry Exhibit
- Arcadia Reptile — Books by John Courteney-Smith
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What about this species makes it special to you?
I love blue tongue skinks because they’re big personalities in a sausage-shaped body. They’re intelligent, inquisitive, fairly easy to care for, and tend to take more interest in humans than what is average for reptiles, which can make them something close to companion animals.