Blue-bellied lizards, or western fence lizards (Sceloporus occidentalis), are common reptiles found across western North America. They are recognizable by their grayish-brown, tan, or black scales. Adult males typically display bright blue patches on their bellies and throats, giving them their common name. Their native range extends from Washington and Oregon south through California, Nevada, Idaho, Utah, and Arizona into northern Mexico. They inhabit diverse environments, including grasslands, chaparral, woodlands, coniferous forests, and farmlands, often seen on rocks, fences, or near water.
Natural Diet of Blue-Bellied Lizards
In their natural habitats, blue-bellied lizards are primarily insectivores, consuming insects and other arthropods. They are skilled predators, often remaining motionless as they scan for prey. They consume a wide variety of invertebrates.
Common prey includes:
- Crickets
- Ants
- Spiders
- Beetles
- Grasshoppers
- Caterpillars
- Flies
- Wasps
- Various worms
While some broader classifications might suggest an omnivorous diet, studies of their stomach contents primarily reveal insect matter, with plant material being largely incidental. The size of insects consumed often correlates with the lizard’s age, with larger lizards preying on bigger insects.
Feeding Blue-Bellied Lizards in Captivity
For blue-bellied lizards kept as pets, a diet centered on live feeder insects is crucial to mimic their natural foraging behaviors. Appropriate feeder insects include crickets, mealworms, waxworms, and dubia roaches. Black soldier fly larvae (BSFL) are also a suitable option, offering a good calcium content.
A practice known as “gut-loading” is essential; this involves feeding the feeder insects a highly nutritious diet before they are offered to the lizard. This process ensures that the insects become “delivery systems” packed with vitamins and minerals that the lizard needs for optimal health. Gut-loading foods can include dark leafy greens like collard, dandelion, or mustard greens, as well as vegetables such as carrots, sweet potatoes, and squash. Commercial gut-loading diets are also available and provide a balanced nutritional profile for the insects. The size of the feeder insect should not exceed the distance between the lizard’s eyes to prevent choking and ensure proper digestion.
Important Dietary Considerations
Beyond the specific types of food, several factors contribute to the overall dietary well-being of blue-bellied lizards in captivity. Young, growing lizards typically require daily feeding, while adults can be fed every other day or three to four times a week. A common guideline is to offer as many insects as the lizard can consume within a five-minute period.
Supplementation with calcium and vitamin D3 is important to prevent metabolic bone disease. Vitamin D3 is necessary for the lizard to absorb calcium effectively, and it can be synthesized through exposure to UVB light or provided as a powdered supplement. Feeder insects should be dusted with a calcium powder, with or without D3 depending on the lizard’s UVB exposure. Providing fresh, clean water daily is also essential for hydration, either in a shallow dish or through misting, as they may drink water droplets.
Certain foods should be strictly avoided to safeguard a blue-bellied lizard’s health. Wild-caught insects may carry parasites or be contaminated with pesticides, posing a risk to the lizard. Many common plants are toxic to reptiles, including azaleas, poppies, and various ivies, and should not be present in their enclosure or offered as food. While mealworms and waxworms can be part of the diet, they are high in fat and should be offered in moderation to prevent obesity and digestive issues.