Like all other animals, lizards employ a number of behaviors to help them meet their needs. While the nearly 6,000 living species have developed a wide range of behaviors, a few are relatively common among the group. The best way to observe these activities in captivity is by providing a large, complex habitat for your pet, with an appropriate thermal gradient. Whenever possible, feed your pet natural food items, which will allow you to observe natural foraging and feeding behaviors.
Lizards employ one of two basic behaviors for finding food. Some actively hunt for food by looking around and flicking their tongues to collect chemical clues from the environment. Other lizards rely on ambushing their prey, which causes them to remain motionless for extended time periods.
Many lizards feed by simply opening their mouth and grabbing the intended food item, be it an insect, rodent or leaf. Others use their tongue to help move the food into their mouths. This type of feeding behavior has become highly specialized among chameleons, who can fire their tongue like a harpoon, and capture an insect at considerable distances.
Some lizards tackle large prey in the wild, and they have had to come up with ways to subdue such animals. Monitor lizards (Varanus spp.), tegus (Tupinambis spp.) and other muscular lizards accomplish this by thrashing their heads wildly after clamping their jaws on their prey. They may also smash the prey animal into the ground to help dispatch it.
Although the thermal preferences of lizards vary widely from one species to the next, several employ behaviors that allow them to keep their body temperatures within a relatively narrow range – a behavior called thermoregulation. For example, bearded dragons (Pogona vitticeps) will move onto an elevated perch under their basking spot shortly after daybreak. As they attain their preferred temperature, they move away from the heat source, and begin foraging.
Some lizards may also adopt unusual body postures to maximize or minimize their exposure to the sun (or heat lamp, in the case of captive lizards). Lizards that need to cool off may even open their mouth, which allows some of their body heat to radiate into the environment.
Hiding or Resting Behavior
When not actively thermoregulating or foraging for resources, most lizards rest to conserve energy. Some species, such as leopard geckos (Eublepharis macularius), rest while hiding in dark spaces; while other species rest on elevated perches or simply lie about in the open. Always be sure to provide hiding spaces for species that normally use them in the wild. Failing to do so may cause your pet to become stressed, stop eating or fall ill.
Some lizards will tolerate living in communal cages, while others will quickly fight with or attempt to consume conspecific cage mates. Many species have evolved methods to communicate with other members of their species, and these often help the lizards avoid conflicts. For example, aggressive male anoles (Anolis spp.) extend their colorful dewlaps and perform a series of erratic pushups to communicate their strength, size and prowess. These and similar behaviors are often involved in breeding interactions as well. Contrary to popular perception, the extraordinary color-changing abilities of chameleons have evolved for communication, not camouflage.
Lizards respond to threats in several different ways. Quick, agile species often attempt to flee perceived danger, which can cause problems in captivity, as they often crash into glass aquarium walls at full speed. Others engage in a series of bluffs and postural changes in an attempt to intimidate threats. If further pressed, many lizards will bite, scratch or defecate to deter attackers. Over time, with consistent, gentle handling, many lizards learn that their keepers represent no threat, and become tractable, potentially even docile, pets.
Although all lizards are individuals with varying personalities, some species-wide generalizations can be made. Many common pets, including bearded dragons, leopard geckos, savanna monitors (Varanus exanthematicus) and blue-tongued skinks (Tiliqua spp.), typically become quite tame. By contrast, most Nile monitors (Varanus niloticus), tokay geckos (Gekko gecko) and basilisks (Basiliscus spp.) respond negatively to their keepers' advances.