The Basics:

Lively, alert and wary, the Collared Lizard will often take a while to warm up to its human keeper. Although only medium in size, Collared Lizards have powerful jaws, and their bite is capable of breaking human skin. So care should be taken when handling them. However, they will grow to accept human handling over time, after gentle, measured and persistent overtures. In nature, Collared Lizards can be found in arid and semi-arid environments stretching from Missouri to California and down into Mexico. Most often they live in rocky areas. They typically grow to around a foot in length, with males being larger than females. Males are also more vividly colored than females, having a green or blue coloration with bands and small white spots, while the females are paler and grayer. A male's throat will also be brightly colored, often blue or
green and sometimes even orange. The belly of a Collared Lizard is much lighter than the back.

Enclosure:
They Need Space:

Collareds are very active lizards, so they must be housed in
enclosures that offer ample room. A single Collared Lizard should have an enclosure that's at least the size of a 40-gallon aquarium, with adequate ventilation. However, a
larger enclosure is more desirable. Male Collared Lizards are very territorial, and should never be housed together. In nature, Collareds are very active predators that will readily
eat other lizards, so smaller animals must not be housed with them. This includes members of their own species, since Collareds are cannibalistic.

Climbing And Hiding Places Required:

Wild Collared Lizards enjoy climbing and basking on rocks. This natural environment must be replicated in their enclosure, with a larger rock or rock pile in the basking area of the tank. If a pile is used, care must be taken to ensure that the rocks are stable, so they will not topple on to the lizard. The top of the rock pile should provide a surface that's large enough to allow the lizard to bask comfortably. Since Collareds are often wary animals, their enclosures must include hide boxes or other places that provide them with a secure retreat. This area can be located in the cooler section of the enclosure.

Lighting:
UVB Lighting Is Absolutely Essential:

Collared lizards need exposure to UVB rays to produce vitamin D3, which is essential to the animal's ability to absorb calcium. Unlike people, lizards like the Collared cannot produce their own Vitamin D3, so they must depend on UVB rays. Without Vitamin D3, a Collared Lizard will not have a sufficient supply of calcium even if it is given a supplement, a condition that will lead to the development of a metabolic bone disease. UVB rays should be provided to the Collared Lizard by a fluorescent bulb that also provides UVA rays and operates on a 10-12 hour on/off cycle. There are a variety of full spectrum lights available at PSP that emit UVB light in combination with UVA light. Fluorescent lamps producing UVB rays should be replaced every six months. Glass blocks out UVB light, so overhead light sources should be kept behind a wire mesh cover, not a glass or acrylic tank top. This light source should be within 12 inches of the animal.

Temperature:
They Like It Hot And Dry:

Collared lizards do best in an enclosure that is hot and
relatively dry. A heat lamp should be used to create a basking area with temperatures of 100-110 degrees Fahrenheit. This area should include a basking rock or rock pile, with
the heat lamp aimed at its highest point. A thermal gradient must be provided in the rest of the tank with temperatures ranging from the upper 70s to upper 80s during the day,
and about 5-10 degrees cooler at night. This will allow the animal to move around its enclosure to regulate body temperature. Heat can be provided by a combination of lamps.
Ceramic heat emitters that give off heat, but no light, can be used to maintain nighttime temperatures, if necessary. Three thermometers should monitor temperature, one in the
warmer zone, one in the cooler zone and one in the basking area.

Diet: Mostly Meat:

Collared lizards are primarily carnivores, but many will also eat plant matter, including collard greens, mustard greens, kale and zucchini. Meat should constitute the majority of the Collared Lizard's diet. Collared lizards will eat commercially raised crickets, mealworms, earthworms, kingworms and roaches. (Wild caught insects should never be fed, since they can carry disease.) All insects should be gut loaded (fed 48-hours before being offered) and dusted with a supplement.  Collared lizards will also take pinkie feeder mice, but these should be fed sparingly because of their high fat content. Plant matter fed to the lizard must be washed, then cut or shred to make it easier to ingest. Uneaten food should be removed within three hours. Adults should be fed 3-4 times a week and juveniles daily. Important -- It is necessary to provide calcium and vitamin supplements as part of the diet. Please read the supplement section below:

The best specific schedule may vary depending on the supplement products used and other factors. Please consult product package directions, outside literature and a veterinarian to determine the optimal supplementing program.