Lizards are diverse reptiles whose diets vary significantly by species, size, and environment. Understanding their specific dietary needs is important for their health and well-being, whether in the wild or as pets.
General Dietary Classifications
Lizards exhibit three primary dietary classifications: carnivores, herbivores, and omnivores. Carnivores primarily consume other animals, often insects, though larger species may eat small vertebrates or fish. Herbivores feed exclusively on plant matter like leaves, flowers, and fruits. Omnivores maintain a mixed diet of both animal and plant-based foods. While few lizards are strictly herbivorous, many are insectivorous or omnivorous.
Species-Specific Nutritional Requirements
Dietary needs vary significantly even within these classifications, influenced by a lizard’s size, metabolic rate, and specific habitat. Bearded dragons are omnivores whose diet shifts with age; juveniles require a higher proportion of insects, while adults primarily consume leafy greens and vegetables. Leopard geckos are strict insectivores and cannot properly digest plant material. Green iguanas are predominantly herbivores, thriving on dark, leafy greens such as collard and dandelion greens, with fruits offered sparingly. While green iguanas may occasionally eat insects in the wild, animal-based proteins should generally be limited in their captive diets to prevent potential health issues.
Providing Food for Pet Lizards
Providing a balanced diet for pet lizards involves careful selection and preparation. Feeder insects, such as crickets, dubia roaches, and mealworms, should be “gut-loaded” for 24 to 72 hours before offering them. This practice ensures the insects are packed with essential vitamins and minerals, which are then passed on to the lizard. Fresh produce should be thoroughly washed to remove pesticides and cut into small, manageable pieces.
Supplementation is often necessary to meet a lizard’s complete nutritional needs, particularly for calcium and Vitamin D3, which are crucial for bone health. Feeder insects or plant matter can be lightly dusted with calcium powder, often alternating between a calcium-only supplement and one containing Vitamin D3. A reptile-specific multivitamin should be provided periodically, typically once or twice a month. Feeding frequency varies; juvenile lizards generally require daily feedings, while adults may be fed every other day or a few times a week.
Harmful Foods to Avoid
Certain foods are toxic or nutritionally inappropriate for lizards. Avocado contains persin, a fungicidal toxin that can cause severe health issues. Fireflies and wild-caught insects should be avoided; fireflies contain a potent toxin, and wild insects may carry pesticides or parasites. Citrus fruits can lead to gastrointestinal upset due to their high acidity.
Onions and garlic are also toxic to lizards. Iceberg lettuce offers minimal nutritional value and should be substituted with more nutrient-dense greens. Vegetables high in oxalates, such as spinach and rhubarb, can interfere with calcium absorption and should be fed sparingly or avoided. Processed human foods, dairy products, and fruit seeds also pose health risks.