Food:
Like all animals, lizards need to eat. Many lizards will consider anything that will fit in their mouth prey (including smaller lizards of the same species), but some are very specialized feeders that only eat certain prey animals. When researching a species' needs, this is very important to learn about, as eating can mean life or death for any lizard.
However, there are other lizards that are not predators, at all. A very common example of this is the giant green iguana, Iguana iguana. These lizards are totally herbivorous, and contrary to some outdated care information, eat nothing but plants their entire life. Feeding a green iguana is more complicated than it may seem, though, as these lizards have very specialized dietary needs. Feeding an iguana nothing but lettuce and broccoli will certainly kill it.
Safety:
All lizards are concerned about their own safety, as the wild is full of predators and competitors. Lizards have a variety of behaviours, some evasive and some defensive, to keep themselves safe.
Many new lizard owners complain that they cannot hold their lizard, because it is always trying to run away or bite them when they try to pick it up. There is a good reason for this, though! Small lizards are eaten by so many other animals, so it's instinct to them to run from anything bigger than themselves. If the lizard didn't run from your hand, it probably wouldn't survive in the wild. Lizard species like the leopard gecko (Eublepharis macularius) and the inland bearded dragon (Pogona vitticeps) that have had many generations bred in captivity seem to be less fearful of people, in-general, and make excellent pets when properly cared for.
Similarly, some lizards are very enthusiastic about biting or whipping you with their tail to discourage you from "eating" them. Other species have very specifically developed defenses. The Australian frilled lizard (Chlamydosaurus kingii) has a large collar around its neck that it displays to predators (or other lizards intruding on its territory) to make it appear larger and more dangerous. Many lizards are covered in tough scales or spines and spikes to make themselves unappealing to predators, like the moloch or thorny devil (Moloch horridus) .
One very familiar, but sometimes shocking to the unexpecting, evasive behaviour is the habit of tail-dropping. This is actually called caudal autotomy, and occurs when the lizard feels threatened by a predator, or has been grabbed by a predator and wants to escape. Read more about caudal autotomy, here.
What is also important to understand is that most lizards do not feel safe when housed with other animals. In an aquarium or cage in captivity, other animals in an enclosed space will seriously stress lizards out in most situations, because they have little room for escape from these possible predators, and they must compete for food, the best hiding spots, and the best basking or warming spots. Keeping more than one lizard in an enclosure (even if they are the same species) should be very carefully planned, and is generally not recommended. Lizards do not get lonely or need company, as they are all competing for the best food, heat, hides and mates.
Heat:
"Heat" is very subjective when it comes to these animals. Hot for some species is not the same for others. Lizards are "cold-blooded"- the proper term is ectothermic. Ectothermic animals depend on their environment to stay within the temperature range that their body works at. Every species of reptile has a temperature where its body works the best at, and it is vital that in captivity, a range of temperatures are provided so that the lizard can warm up or cool down as it pleases. Read more about temperature gradients and ectothermy here.
Reproduction:
Reproduction is the only instinctual drive that preserves the species instead of the animal itself. Creating more lizards is a huge drain on the animal's body. If your lizard is to be a family pet, it is best not bred because breeding will cause a lot of stress to the animal.
There are many species that are threatened in the wild, partly due to collection for the pet trade. Some species really need captive breeding efforts so that there will be less of a need to collect them from the wild.
The Enclosure:
Go to any pet store with a large reptile section, and you will find many types of cages. Aquariums, plastic caging and screen or mesh caging are the most popular in pet stores, but custom-built wood enclosures work well, also. You will have to research the needs of the species that you would like to keep to find out what type (and size!) of enclosure will be most suitable. Basically, follow the three S's: Safety, security and size:
- The enclosure must be safe: It should not contain any toxic materials, loose shelves, uncovered nails or screws, and heating devices must be shielded or outside the enclosure.
- The enclosure must be secure: This means that the enclosure should be totally escape-proof! The lid must fit on tightly, or the door must tightly close. For large, strong lizards, consider a locking mechanism. There should also be no gaps, cracks or holes in the walls, corners, lid or door.
- The enclosure must be appropriately sized: You need to research the minimum enclosure size for the lizard(s) you want to keep. Larger than the size recommended for a given species is almost always better.
Substrate:
Substrate is whatever is covering the floor of the enclosure. There are two general categories of substrate: Particulate and sheet. Particulate substrates are any that consist of lots of little pieces, like soil, sand and gravel. Sheet substrates are any that consist of large sheets of material, like carpeting, paper towels and newspaper.
Basically, natural substrates can work very well if kept meticulously clean, but simple substrates far outweigh most natural substrates safety-wise. Do not underestimate the usefulness of paper towels and unprinted newspaper as substrate, as these are both safe, easy to replace, and cheap (although printed newspaper should not be used with small lizards, as the fumes may be toxic). Some lizards need a substrate that they can burrow underneath to feel safe, and they should be provided a substrate that allows them to do this.
You should properly research the needs of any lizard before placing in on a substrate, but still be cautious of advice given. For example, many owners keep their leopard geckos (Eublepharis macularius) on sand, but leopard geckos are from rocky mountainsides where the ground is rock or hard-packed dirt. Similarly, there is not a single species of lizard that lives solely on woodchips, or on crushed walnut shell or corn cob in the wild. No lizard lives on newspaper or carpet in the wild either, but the safety of these sheet substrates outweighs the fact that they are not natural.
All particulate substrates have a risk of being ingested and causing an impaction in the animal's digestive system, called an intestinal impaction. This means that some of the substrate is swallowed (often accidentally, but sometimes on purpose by a curious or hungry lizard), and gets stuck somewhere in the stomach or intestines. It causes a blockage that stops digested food from passing and have the nutrients absorbed from it. This causes a slow death of either starvation since the lizard usually loses its appetite, or food that cannot be excreted can become rancid in the animal's stomach and kill it. If the lodged substrate is sharp, like a woodchip, crushed walnut shell or corn cob, it can rip and tear the intestinal lining and cause serious internal damage which will most likely kill the lizard. Lizards with impactions must be seen by a qualified reptile vet.
Read an article on the advantages and disadvantages of many substrates here.
Cage Furniture:
Just like how people usually feel more comfortable with chairs to sit on, tables to eat off of and beds to lie on, lizards need something to make their enclosure more interesting and stimulating.
The most underappreciated item in any lizard's cage is the most simplex: The hidebox. Lizards need places where they can escape from view, so that they don't feel like they are in plain view of predators and competitors all the time. For ground-dwelling lizards, a cardboard box or plastic container with a hole cut in the side is simple, but effective. Slabs of bark and wood, and rocks will also allow the lizard to hide from view. For arboreal lizards, plants, branches and slabs of bark leaned against the enclosure walls are all possible hiding spots. Be sure to place hiding spots in both warm and cool ends so that the lizard may be comfortably warmer or cooler in privacy.
Depending on the habits of the lizard being kept, other appropriate cage furniture should be present in the enclosure. Arboreal lizards will fare well with plenty of branches to climb and bask on (keep in mind that branches should be at least one and a half times as wide as the lizard's body so that the lizard may comfortably climb and rest on them). These branches should be surrounded by live or fake plants to provide plenty of hiding places high in the enclosure.
Terrestrial lizards will appreciate slabs of cork bark to hide under, and many prefer substrate they can burrow in (but pay attention to the species' needs). Rocks add interest to the terrain, as well as low branches.
Heating:
Lizards are ectotherms, so their environment must have a range of temperatures so that they may thermoregulate. This is so that the lizard can adjust its body temperature to the temperature that the species prefers. Most lizards need to have something to supply extra heat to provide the thermal gradient that they require.
The temperature of the enclosure is vital. Every species' body works best at a given temperature, and providing a range of suitable temperatures (the thermal gradient) so that the lizard may thermoregulate is extremely important. When researching a species' specific needs, you will likely encounter a temperature range under its heat requirements. This is not a range of temperatures that the lizard will be healthy at, but is the range that you must provide in the enclosure. The warm end of the enclosure should be at the top of the range, the cool end at the bottom. At least two thermometers are absolutely necessary to properly monitor the temperature in the enclosure.
The type of heat you provide is important, as well. Diurnal lizards (those that are active during the day) are heliotherms, meaning that to adjust their body temperature they move in and out of sunny areas and bask. Heliotherms should be provided overhead heat, like with an incandescent light bulb or a ceramic heat emitter. Nocturnal lizards (those active at night) are thigmotherms, and warm themselves on the ground that was previously heated by the sun. These lizards are safely heated with an undertank heating pad, which can be left on day and night. Crepuscular lizards are those that are active at dusk and dawn. A cominbation of both heating methods may be necessary if nighttime cage temperatures fall too low without a heating pad, but they are often kept successfully when treated like heliotherms.
Read more about heating ectotherms properly, here.
Lighting:
Many new lizard owners do not realize how important the role of proper lighting is to a lizard's health. All diurnal (active during the day) species require a wide-spectrum bulb that produces UV-B wavelengths (most often found in fluorescent bulb format, and compact fluorescents that produce UV-B have recently hit the market). UV-B lighting is necessary for the lizard to produce vitamin D3 (often called the "sunshine vitamin" in people), which is needed for proper calcium absorption. Lack of this proper lighting will eventually cause a severe calcium deficiency in diurnal lizards, which can kill the animal rather slowly and painfully. Please note that "basking" bulbs do not necessarily produce UV-B, and plant and aquarium bulbs do not, either. The bulb's package must state that it produces UV-B wavelengths. Read more about calcium and UV-B, here.
Photoperiod, or the number of hours of daylight, is also important. Providing too many or too little daylight hours may stress a lizard, especially more delicate species. Research the number of hours of daylight that is typically provided for the species you are keeping. Also, the photoperiod naturally changes with the seasons, and a change in the photoperiod (as well as temperature) may be necessary to stimulate breeding behaviour in some animals. Generally, for tropical species, during spring and summer 14 hours of light to 10 hours of darkness is acceptable. During fall and winter, the daylight may be reduced to 12 hours of light to 12 hours of dark. For temperate species, 12 hours of light to 12 hours of dark year-round often works just fine.
Humidity:
Like lighting, humidity is often overlooked by novice herpers. Humidity is a measurement of water evaporated in the air, and is expressed as a percentage. It is measured by a device called a hygrometer, which can be found as small gauges for the lizard enclosure. Improper humidity may cause both shedding and respiratory problems. When looking into your lizard's needs, the proper humidity levels should be listed.
To increase the humidity in an enclosure, add a wider water dish, reduce the amount of ventilation area on the enclosure, mist the enclosure frequently, or add some water-loving, nontoxic plants. Conversely, do roughly the opposite to lower humidity: A smaller water dish (unless the species likes to submerse itself in water), increase the ventilation area, do not mist as frequently, and use fake plants instead of live. Leaving a small, relatively quiet fan on near the enclosure may also help.
Many species seek out a hiding spot with higher humidity than the rest of the enclosure (particularly species from dry environments). In captivity, a "humid hide" is often provided so that these lizards can satisfy their moisture needs. These hides are often used when the lizard is preparing to shed. A humid hide is often as simple as a plastic food container with a hole cut in the side for entry and exit, and is filled with damp sphagnum moss or paper towels.
Read more about providing proper humidity, here.
Feeding:
All lizards need to eat, and proper nutrition is important for their health. All lizards can be classed into one of three general categories: Carnivores, which feed on other animals, herbivores, which feed on plants, and omnivores eat both animal and plant matter. Most species will eat a particular type of food (for example, many carnivores are insectivorous, meaning they eat mostly insects and other invertebrates), and some species are specialists and are even more specific about what they eat.
Horned lizards (Phrynosoma sp.), for example, are specialized ant predators; a single horned lizard may eat thousands of ants every day. In captivity, most horned lizards are reluctant to switch to an easier-to-provide prey such as crickets, so these animals do not fare very well as pets.
All owners of carnivorous lizards should be familiar with the concept of gut-loading prey. Since you are what you eat, making sure your lizard's prey is healthy and full of nutrients will ensure that your pet will be getting those nutrients, meaning that you need to feed your lizard's prey high-quality food.
Insects are very rarely fed well in the pet store, and should be gutloaded accordingly. Crickets can be gut-loaded on fruits and vegetables, fish flake food, chick mash or a pre-made cricket chow. Mealworms should be housed on rolled oats (that they will eat), and given slices of semi-moist fruits and vegetables every other day. Silkworms will only eat mulberry leaves and feed made of them.
Rodents should also be fed a high-quality diet. If you buy your mice or rats frozen, then purchase them from a reputable supplier.
Herbivorous lizards can be a little more challenging to provide adequate nutrition, since most of the fruits and vegetables people eat are actually quite poor nutritionally. Research the needs of the actual species you will be keeping, but in-general, a varied diet of calcium rich vegetables and fruits that are low in nutrient antagonists such as oxalates, phytates, and goitrogens is the way to go.
We do not yet know the exact nutritional requirements of any lizard species yet, but we do know that supplementing a lizard's diet with vitamin and mineral powders can improve its health. The general rule of thumb for supplementing is as follows: For juveniles, calcium-only powder 6-7 times a week, and a multivitamin powder 4-6 times a week. For adults, calcium should be provided 4-5 times a week, and vitamins 3-4 times a week. Females that are gravid (pregnant) or recovering from egg production should be offered food with calcium seven times a week to make up for calcium losses to the eggs and offspring.
The "shake and bake" method for supplementing prey is simple; drop the prey into a plastic bag or container with a mix of the powders inside, and shake until they are coated. For herbivores and omnivores that are eating food out of a dish, a small pinch of the powders mixed in well with the food works fine.
