Wild lizards consume an extremely varied diet, ranging from scorpions to marine algae, and pets also do best when fed a variety of foods. When this is impossible, the foods you provide must be supplemented with vitamins and minerals formulated for reptiles.
Know What Your Animal Eats
Lizards can be herbivorous, insectivorous or they can be omnivorous. Before you buy your animal, make certain you're going to be able to provide it the diet it needs. Most lizards have high metabolic rates and require five to seven feedings per week.
The vast majority of insectivorous lizards will thrive on a diet of crickets, roaches and wild-caught insects dusted with a vitamin supplement. Insects are easy to feed to your pet and are readily available. Start with a half dozen or so to see how many your pet will eat.
You can buy live crickets at most pet shops. Vary the insects with insect larvae such as super mealworms and waxworms (These wormlike creatures are the earliest stage of developing beetles. Use them before they develop the formidable jaws they'll have as adults).
First, make sure you buy insects of the proper size for your pet. Then, before the feeding, dust them with a vitamin/mineral supplement that contains calcium and vitamin D3. Calcium supplementation is particularly important in preventing metabolic bone disease, or MBD, a serious bone degeneration that happens when a reptile gets too little of the mineral. Place the feeder insects in a small jar with a pinch or two of the supplement; cover the jar and shake it to coat the insects with the powder. These coated insects are known as "shake and bake" feeders.
A note of caution. There are limits. Dietary specialists such as horned lizards that subsist on ants are nearly impossible to maintain on artificial diets.
Wild-caught insects should be offered whenever possible. You can buy a commercial trap or catch them by sweeping a net through tall grass. This will provide an excellent assortment of food items. You can sort these out for size by putting the appropriate size holes in the container in which you're holding them.
If you're keeping your own supply of insects, feeding them with fish food flakes sprinkled with a supplement powder gives the insects the vitamins that the pet will need. You can also provide the insects with vegetables and fruits such as yams and oranges that will translate into more vitamins for your pet. This is known as "gut loading."
Many insects may attack your pets at night when lizard metabolism slows down (in green anoles, for example) and may also consume your pet's eggs or young. If you're concerned, make certain that all the food is consumed before dark. Viewing lights with wavelengths invisible to reptiles are available and will help keep an eye on your pet at night. On the other hand, there are nocturnal species such as the tokay gecko that should be fed only in the evening, when they will feed quickly.
The dietary requirements of herbivorous species are more easily met, especially if you shop in markets with produce from other countries. Salads offered to herbivorous species should be finely chopped and mixed so that your pet cannot pick out his favorites and leave the rest. Vegetables with excellent nutritional value are avocado, turnip greens, broccoli, cabbage, celery, cauliflower, Swiss chard, okra, dandelion greens, blueberries, cantaloupe and bok choy. These provide sufficient vitamins and calcium.
Feel free to experiment. Many lizards are attracted to yellow vegetables, and dandelion flowers often work when all else fails. (Consider freezing a supply since they have a short flowering season.) Although spinach might seem like a good idea, the oxalic acid in spinach combines with calcium to form kidney stones, so avoid it.
Feed once a day, larger meals for growing lizards, smaller meals for adults. Put the salad in a bowl so the pet does not ingest substrate from the tank along with its meal. Reluctant feeders may be tempted by the addition of mealworms.
Monitors can be fed on canned diets found in pet shops. These diets are relatively new and they're best supplemented by insects and mice. Monitor lizards and tegus will also eat rodents. Since live rodents can attack and harm your animals, give them pre-killed baby mice available frozen in most pet stores. Defrost in warm water before feeding them to your pet.
The metabolism of ectothermic (cold-blooded) animals such as reptiles and amphibians depends upon the temperature in which they're living. This means that the warmer the temperature of their surroundings, the faster their metabolism and the more food they will consume. At extremes of temperature, however, they will either stop eating or be unable to process the food. Your pet will need temperatures between 85 and 105 degrees Fahrenheit (depending on the species) to utilize the nutrients in its diet.
If you keep several lizards, be aware that the dominant one may inhibit the others, so remove that animal at feeding time.
Generally, use small food items rather than big ones. The smaller it is, the easier it will be for a lizard to digest. Also, immature insects have fewer indigestible parts (legs and wings) than do adults.