Collared lizards (Crotaphytus spp.) are diurnal, terrestrial lizards, typically 8-12 inches long, native to the southwestern United States and northern Mexico. Known for their slim, athletic build, large heads, long legs, and slender tails, these lizards have become popular pets. This article provides a detailed guide to understanding and meeting the dietary and care needs of eastern collared lizards, ensuring their health and well-being in captivity.
Understanding Collared Lizards
Collared lizards, including Crotaphytus collaris, are distinguished by the two black collars around their necks. Adult males often exhibit bright green scales, along with tan, olive, brown, bluish, and yellow scales, while females are typically less colorful. These lizards are notable for their ability to run on their hind legs and can achieve speeds where their stride is up to three times their body length. They inhabit various environments, including sagebrush, desert scrub, pinyon-juniper forests, and desert grasslands, with a preference for rocky areas and open vegetation. Their range extends from Missouri to southeastern California, Arizona, New Mexico, and northern Mexico.
Creating the Ideal Habitat
Enclosure
The absolute minimum enclosure size for a single collared lizard is 36” x 18” x 18”, equivalent to a 40-gallon breeder-style tank. While cohabitation is possible, housing multiple males together is not recommended due to their aggressive tendencies. A 75-gallon tank can comfortably house one male and two females; adding more width can reduce stress when housing additional females. However, males can become overwhelmed if there are too many females present.
Substrate
An ideal substrate is washed play sand, which has had the sharp silicates removed. Other options include eco earth, top soils, and washed play sand and soil mixes. The substrate should be at least 4 inches deep to allow for burrowing. It is important to monitor hydration and the amount of sand being consumed. Routine substrate changes are necessary to prevent the overgrowth of bacteria or parasites, unless a bioactive enclosure is established.
Decor and Enrichment
Enclosures should include a basking area, a hide, a water dish, and décor to provide enrichment. Since collared lizards are terrestrial and prefer rocky terrain, a flat basking stone and several hiding places are essential. An empty enclosure can lead to boredom, reducing the lizard’s quality of life.
Read also: Dietary Habits of Whip-poor-wills
Lighting
Collared lizards are diurnal desert species that require high-output UVB lighting for proper vitamin D3 synthesis. The ideal light cycle is 12 hours of daylight and 12 hours of darkness, achievable with a timer connected to the lights. UVB lights lose strength over time and should be replaced every 6 months. Natural sunlight is beneficial, but windows and glass block UVB rays, and screens can decrease its strength. For optimal UVB provision, use an Arcadia Desert T5 HO 12% bulb, roughly half the length of the enclosure, placed on the warm side. Mount the bulb in a reflective T5 HO fixture, such as the Arcadia ProT5 or Vivarium Electronics T5 HO fixture.
Heating
Collared lizards are ectotherms, relying on their environment for body temperature regulation, which is crucial for metabolism, digestion, and overall health. During the day, the basking area should reach 104-118°F (40-48°C), with a cool side temperature of 77-90°F (25-32°C). Nighttime temperatures should be maintained between 68-79°F (20-26°C). A halogen heat bulb placed above the basking branch is an excellent heat source. Use a cluster of two 50w PAR30 halogen flood bulbs, adjusting the height or using a plug-in lamp dimmer to achieve the correct temperature. Temperatures should be monitored with an infrared thermometer and a digital probe thermometer placed on the basking surface.
Humidity and Hydration
Ideal humidity for collared lizards ranges from 20-40%, monitored using a hygrometer inside the enclosure. A clean water source should always be available for drinking. Humidity aids in shedding and prevents dehydration but can cause respiratory issues if too high. Western species thrive with humidity below 40%, while eastern species prefer 50-70%. Mist the enclosure once a week for western species and daily or every other day for eastern species. A humid hide should also be provided to help maintain hydration.
Nutrition and Diet
Nutrition is critical for the proper growth and development of collared lizards. Understanding appropriate food choices helps maintain their health and prevent medical complications.
Feeding Schedule
Baby and juvenile collared lizards can be fed 2-3 times a day, while adults can be fed 1-2 times a day or as needed to maintain their desired weight.
Read also: Red Bat Feeding Habits
Food Choices
Collared lizards are primarily insectivores, consuming mainly insects. While greens can be offered, they should not be a routine part of the diet, as collared lizards lack the necessary GI flora to absorb nutrients effectively from them. Overconsumption of greens can lead to health complications. Offering greens no more than once a week is acceptable if the lizard consumes them, though they generally prefer live prey.
Appropriate feeding methods include offering 2-3 dusted insects in the morning and evening, 4-5 dusted insects once daily, or 5-8 dusted insects every other day, depending on the lizard's age.
Recommended Insects
Offer a variety of insects to provide a balanced diet. Options include:
- Crickets (the most common food source)
- Hoppers (young, wingless locusts)
- Dubia roaches
- Discoid roaches
- Locusts/grasshoppers
- Mealworms (in moderation)
- Superworms (in moderation due to high fat content)
- Black soldier fly larvae
- Waxworms (only in moderation, as they are very fattening)
- Hornworms
- Phoenix worms
- Silkworms
- Butterworms
- Darkling beetles
Avoid feeding excessive amounts of mealworms due to their exoskeletons, which can cause digestive problems.
Vegetables and Treats
Some collared lizards may eat chopped vegetables, but most will not. If offering vegetables, avoid lettuce, which can cause excessive gas and stomach swelling. Suitable options include collard greens, cactus pad, spring mix, arugula, kale, pea shoots, alfalfa, bok choy, carrot greens, spinach, dandelion greens/flowers, hibiscus leaves/flowers, cloves leaves/flowers, and squash blossoms. Ensure any flowers are free of pesticides.
Read also: Eating Habits: Eastern Coral Snake
Treats such as papaya, fig, apple, prickly pear, berries, or cherries can be offered sparingly, less than once a week.
Supplementation
Supplementing your collared lizard’s diet with calcium and vitamins is essential. Dust feeder insects 2-3 times a week with calcium. Consult with a veterinarian about the possible need for vitamin D3 supplementation. Additionally, provide a calcium dust or multivitamin with Vitamin A at least 2-3 times a week. Repashy Calcium Plus LoD is a recommended supplement.
Hydration
Collared lizards obtain most of their moisture from their food. Ensure that insects are well-hydrated before feeding them to your lizard. If your lizard does not drink from a water dish, try dripping water on its nose with a pipette or placing ice cubes on a high rock to drip onto lower rocks.
Handling and Enrichment
Supervised Time Outside
Provide a clean, item-free area for supervised activity outside the enclosure.
Outdoor Enclosures
Outdoor enclosures are beneficial for providing natural sunlight and environmental stimulation when weather permits.
Handling
Handling can help build trust and provide enrichment. Captive-bred collared lizards are more likely to tolerate handling than wild-caught individuals. Introduce yourself with food and allow the lizard to climb onto your hand. Pick up the lizard gently from below, supporting its body, and avoid approaching quickly from above.
Recognizing Sexual Dimorphism
As adults, collared lizards exhibit clear sexual dimorphism:
- Femoral Pores: Adult males have more prominent and larger femoral pores (lines running along the ventral aspect of their femur).
- Hemipene Bulges: Adult males have enlarged bulges around the ventral aspect of their tail base.
- Dewlap Coloration: Males tend to display a dark-colored/pattern-spotted dewlap.
- Post-Anal Scaling: Males tend to have larger post-anal scaling.
- Post-Anal Spotting: Females often have two dark spots near their vent.
Veterinarians can also determine sex through probing for hemipene pockets, endoscopic sex determination, and ultrasound sex determination.
Health Considerations
Quarantine
If you already have pet reptiles, quarantine your new collared lizard before introducing it to its new home to prevent cross-contamination of parasites.
Faeces
Normal faeces should be solid, contain a white spot (urate), and be produced regularly. Liquid or smelly faeces may indicate too much vegetation in the diet. Remove faeces daily to prevent bacterial growth.
Lethargy
If your lizard is lethargic, check the temperature first. Maintain basking temperatures of 105-120°F and cool-end temperatures of 77-90°F.
Emaciation/Lack of Appetite
Consider whether the lizard is female and may have laid eggs. Remove the female if she is protective of her clutch and carefully remove the eggs to a warm location.
Parasites
Wild-caught lizards often have worms or mites. Have faecal samples tested by a veterinarian to identify and treat worms. Check for mites in the folds of skin at the top of the thighs and forelegs.
Responsible Ownership
Before purchasing a collared lizard, research reputable breeders or shops and ensure the animal is healthy. Look for signs of good health, such as a decent weight, bright eyes, alertness, and the absence of cuts or abrasions. Always prioritize captive-bred animals over wild-caught ones to reduce the impact on wild populations and ensure a better-adjusted pet.