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Choosing a Green Iguana

The green iguana is considered by many to be the most popular pet reptile on the market. Most are farmed in Latin America, but some are collected from the wild in Latin American countries. A few are captive bred. Additionally, the green iguana can now also be found in south Florida where it is so firmly established that there are now cautionary road signs depicting crossing iguanas in Key Biscayne!

This lizard is essentially a leaf-eater by nature, and despite it propensity for eating other items when they are offered, he should be maintained on a diet of about 95 percent healthy greens and vegetables and 5 percent fruits.

Hatchlings are bright green, often with black bands. Adults are duller gray-green but intensify in color (some turn predominantly fire-orange) during the breeding season.

Baby iguanas remain fairly close to the ground, but adults are primarily arboreal. All sizes can run swiftly and swim well.


The great green iguana is a master of his environment. This lizard can climb agilely, swim admirably, run swiftly, and leap when necessary. Wild iguanas bask extensively but flee at the slightest disturbance. When taken captive, wild collected adults (especially the males) may repeatedly batter their nose against their cage in their attempts to escape. Even with slow, gentle overtures, it may take considerable time to begin to win the lizard’s confidence and some may never become trustful. Babies, and some females, are more approachable than the males.

Iguanas can and do bite. They have strong jaws and sharp teeth. Even a casual (as opposed to an aggressive) bite from a sizable iguana can cause a nasty wound.

Tame, sexually mature iguanas often become aggressive during the breeding season. An adult male may especially become aggressive toward his owner if he feels his dominance in being challenged.


Because green iguanas have dominated the pet trade for more than 5 decades, it may now be the world’s most readily recognizable lizard. You can tell adult males and females apart by their appearance. Males are the larger sex, attaining a length of more than 6 feet. Male iguanas have a very tall vertebral crest of separate elongate scales and huge jowls. The females are more diminutive, seldom reaching over 4 1/2 feet in length, and have smaller jaws and a lower vertebral crest. Except during the breeding season (when they are brightly colored) adults tend to be a dull gray-green in color. Babies lack a well-defined crest but are vividly bright green, slender and long-legged. This species has one or two greatly enlarged disc-like scales on the jowls.

The tail of the iguana is about two-thirds of the lizard’s total length and is used as a defensive weapon by the lizard. A single “whop” can cause skin swelling or even lacerations.


In captivity, iguanas eat a great many unnatural foods. The majority of these are not beneficial to the iguana; those with high animal protein contents seem to cumulatively impair the health of your iguana. Iguanas thrive on a diet consisting of 95 percent healthy greens and vegetables and 5 percent fruits.

Feed your iguana chopped collards, mustard, beet and dandelion greens. Augment this with escarole, romaine, hibiscus leaves and blossoms, nasturtium leaves and blossoms, chopped kale, chopped bok choy, chopped cabbage (the darkest outer leaves are best) and some fruits. Make sure to offer a wide variety of foods since feeding the same food consistently can result in problems related to either excess or deficiency of certain vitamins and minerals. Prepared commercial iguana diet (find the brand with the lowest percentage of animal protein), can be offered but should only be used as a supplement and not the primary diet. Other possible food items include peanut butter sandwiches on whole wheat bread, slices of dark bread, a mixture of cooked rice, oatmeal, black beans, green peas and corn.

A sizable shallow container of fresh drinking water should always be present.

Fast growing babies and ovulating females should be given a D3-calcium supplement twice weekly. For adult males, provide vitamin-mineral supplements at least once every two weeks.


Baby iguanas can be purchased so cheaply, and are so endearing, that many are bought on impulse. This is sad, for they are not the easiest lizard to keep. Nor, when that impulse-purchased baby iguana becomes tiresome, are they the easiest of lizards to find homes for.

A well-maintained baby iguana does not remain a baby for long. They grow quickly and some can grow over 6 feet! They also have long life spans (some live more than 20 years). You need to consider their longevity and their housing before choosing a green iguana.

A 7 to 10 inch long baby could, in a pinch, be kept in a 10 gallon terrarium. Larger is always better. An adult iguana needs a cage at least 8 feet long, 4 feet wide, and 8 feet high.

Crisscross the cage with sizable diagonal and horizontal limbs (at least the diameter of the lizard’s body). Visual barriers offer the lizards a feeling of security that is important to them. Light and warm one end of the highest perch to 95 to 100 degrees Fahrenheit with a UV-B-heat bulb. It is very important to make sure the bulb gives off sufficient UVB. Many bulbs that claim to be full spectrum do not produce sufficient UVB to keep your iguana healthy.

The terrarium’s ambient daytime temperature should be a humid 85 F. Nighttime temperatures can drop by a few degrees. A substrate of mulch (of some non-aromatic form) will maintain a high cage humidity and ease of cleaning. Greenhouses and spare rooms can also be adapted for housing your iguana.

A large but shallow water receptacle will be enjoyed by these lizards. The water temperature should be maintained at about 85 F. This can be accomplished by using an undertank-heating pad. The water must be kept fresh and clean.

Common Diseases and Disorders