Did you know that there are over 4,500 species of lizards on this planet of ours? According to the San Diego Zoo, they can be found on every continent in the world, minus Antarctica. However, while lizards are common household pets, fewer than 30 species comprise the pet trade.
Whether you are a new lizard owner, trying to be friends with the lizards in your garden or a reptile lover, you may wonder what do lizards eat? While diets are as variable as their environments, every lizard can fit into one of four diet categories: insectivores, carnivores, herbivores, and omnivores. Once you find out what they eat and their dietary restrictions, feeding them is simple.
What Do Lizards Eat?
If you wonder what lizards eat, the answer is not one lizard's diet fits all. Lizards eat anything from leafy greens to insects, and some even eat meat. Different lizard species require different diets. No matter what species of lizard you have, they will fit into one of the following categories.
Types of diets
Common pet lizards are usually insectivores, meaning that they eat a diet composed primarily of insects and other invertebrates. Examples include leopard geckos, whiptail lizards, anoles, fence lizards, and chameleons. In captivity, their diet can consist of crickets, locusts, and mealworms. However, most invertebrates have an exoskeleton low in calcium. To combat a potential nutritional deficiency, one can "gut load" the insects by feeding them calcium-rich foods post-purchase.
Lizards such as Gila monsters, komodo dragons, and monitor lizards are considered carnivores, eating high animal fat and protein diets. Their only source of carbohydrates comes from the guts of their prey. The size of prey should correlate with the size of the lizard, i.e. small lizards get fed small prey. It is not recommended to feed live prey as this is considered inhumane and may induce prey-related trauma. The quality of freshly killed prey is the same as live prey. Carnivorous lizards will often eat eggs, chickens, mouse or rat pups, or adult mice and rats.
Large lizards like komodo dragon usually will look for larger prey and is considered a violent predator. They prey on pigs, deers, and even human beings.
Herbivores, like the green iguana and uromastyx, eat plant-based diets. Meaning they only eat plants and fruits. Herbivores can digest plant fiber they normally would not be able to digest with the help of microbes in their enlarged hindguts. Diets can be commercially prepared or vegetable mixes and should be well washed and human-grade. No matter the source, herbivorous diets should be high in Vitamin A, calcium, and cellulose while being low in fats and fermented sugars. Tropical lizard species may also be fed fruit.
Omnivorous lizards are usually fed a combination of all the above diets, including insects, vertebrate prey, and a mixture of vegetables. Examples include bearded dragons, blue-tongued skinks, and green iguanas. Many omnivorous lizard species eat when juveniles can become more herbivorous as they age.
What do baby lizards eat?
A proper and balanced diet for babies and young lizards is very important. In the first few months, they are developing muscular and skeletal systems. Depends on the species of baby lizard you have, the diet will vary. And the good news is most lizards aren't too picky about what they will eat. Baby lizards will usually eat more food than adult lizards because they are growing rapidly, so it is important to provide a balanced diet.
Typically, baby garden lizards eat insects and some fruits and vegetables. Their feeding frequency will be lessened as they grow into adults. The exact amount and frequency vary based on species, sex, and growth rate.
Common nutritional problems:
Poor husbandry often leads to nutritional problems in pet lizards. Poor feeding habits, poor quality foods, and general ignorance of their pet's needs can lead to everything from vitamin level imbalances to obesity to starvation to hepatic lipidosis. Typically, supplemental vitamins and minerals are recommended, depending on the lizard's diet. Most supplements are in powder form and can be dusted on insects or produce.
Vitamin A deficiency (hypovitaminosis A) can lead to hyperkeratosis (a thickening of the outer layer of the skin) or squamous cell metaplasia (an abnormal change in the nature of a tissue). Hypovitaminosis A can also affect cartilage development and overall growth. Herbivores receive Vitamin A by converting beta-carotene in the plants they eat, while carnivores have to get it from the animals they eat.
Nutritional secondary hyperparathyroidism (NSHP)
Metabolic bone disease, specifically nutritional secondary hyperparathyroidism (NSHP), is another common problem in reptiles. Low calcium levels stimulate the parathyroid gland to mobilize calcium from bones into the bloodstream to maintain homeostatic levels. Diets that cause NSPH are often low in calcium and high in phosphorus such as crickets, skeletal muscle meat, day-old chicks, and neonatal mice. This condition mainly affects juvenile lizards, but it can occur in adults too. Lizards that are fed neonatal mice that do not have mineralized skeletons can also be affected.
Vitamin D Toxicity
Many inexperienced lizard owners will over-supplement vitamins or feed dog or cat chow to herbivorous lizards. This sometimes leads to high doses of Vitamin D, a toxic condition causing calcification of body organs.
Captive reptiles, including lizards, spend less energy than those in the wild and therefore have fewer caloric needs. Wild lizards will often spend most of their time foraging for food, while captive lizards have their food provided for them. Pet lizards will also have higher quality food fed to them. However, feeding fatty foods, such as obese mice or waxworms, can also lead to rapid growth in juveniles and obesity in adults.
Unlike mammals, reptiles do not rely on food to maintain their body temperature. Therefore, their meal frequency is often less than that of warm-blooded animals. Wild lizards can survive physiological starvation during times of hibernation, drought, and food shortages. Unfortunately, many pet owners will mistake starvation due to poor husbandry or illness for these periods of physiological hibernation. A common cause of stress and maladaptation is an inappropriate diet consisting of unsuitably sized or colored food.
Excessive amounts of triglycerides in liver cells (often triggered by a period of starvation) can lead to hepatic lipidosis in lizards. Hepatic lipidosis is commonly seen in non-breeding females and obese animals fed a high-fat diet, such as obese mice or waxworms.
What can and can't lizards eat
Never feed your lizard fruits and vegetables directly from your garden, as they can be covered in pesticides and other harmful chemicals that can lead to sickness. Always wash before feeding.
- Honeydew melon
- Dandelion greens
- Sweet potatoes
- Bell peppers
- Swiss chard
- Collard greens
- Romaine lettuce
Never feed wild-caught insects or warms as they may carry parasites and cause your lizard to get sick.
- Wingless fruit flies
What lizard can't eat
Below list of foods are either toxic or not nutritious enough for lizards.
- Iceberg lettuce
What about water? Keeping your lizard hydrated
Most lizards will need water to survive, and water sources should be changed every 24 hours. Containers should be cleaned daily with soap and water and disinfected weekly. Some lizard species are able to absorb water through their skin and will not drink from containers, and therefore mist sprayed on décor and/or plants twice daily, or a drip watering system must be incorporated.
Feeding the appropriate diet to pet lizards is a key part of their husbandry. No matter the diet, high-quality food items should always be used. Not doing so can lead to serious medical conditions that may require veterinary attention. When in doubt, always seek veterinary counsel to ensure you're doing the right thing by your lizard.