Green Iguana

Common Iguana, Giant Green Iguana

Family: Iguanidae Green Iguana, Iguana iguana, also called Common Iguana and Giant Green IguanaIguana iguanaPhoto © Animal-World: Courtesy David Brough
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My son lives with his grandma and he left me to take care of his iguana Godzilla and the other day I had him our on our Dec at our new house and he went in the... (more)  Brooke schneider

The Green Iguana is one of the most popular pet lizards, but it grows big... very big!

The Green Iguana is an exotic attraction with its beautiful coloration, large size, and unusual dinosaur like appearance. This is one of the largest lizards in the Americas, and a full grown Iguana is truly an impressive pet. Amazingly enough, it can also be housetrained to newspaper. Being a big animal, however, it needs lots of room and lots of food, and it can live for 15 or so years. .

Green Iguanas are readily available as a pet and are inexpensive. Some desirable traits of this lizard are that they are very hardy, easy to tame, and are relatively odorless.

They are awesome to look at and fun to keep, but they are a more specialized lizard in their habitat and care requirements than many of the readily available smaller types of lizards. Due to their extensive needs, they are not necessarily the best pet lizard for most beginners. Yet they can easily fit into a wide variety of lifestyles and home environments for those owners that can provide the space and care they require.

The Green Iguana can become quite tame and does not require constant attention. Because of this, many consider them to be the ideal pet. However they are not affectionate, and they do not particularly like to be picked up. You should not choose them as a pet to share love and affection. Rather this is a pet to be enjoyed for its unique and exotic qualities; its appearance, size and lizard behavior.

For more information on keeping pet lizards see:
Reptile Care: Keeping Reptiles and Amphibians as Pets

Geographic Distribution
Iguana iguana
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  • Kingdom: Animalia
  • Phylum: Chordata
  • Class: Reptilia
  • Order: Squamata
  • Family: Iguanidae
  • Genus: Iguana
  • Species: iguana

Scientific NameIguana iguana

Habitat: Distribution/BackgroundThe Green Iguana Iguana iguana was described by Linnaeus in 1758. They are found in Central America and south, all the way to the bottom of South America; Mexico to Southern Brazil and into Paraguay, in the Caribbean and in the Lesser Antilles. They have been introduced to Grand Cayman, Puerto Rico, Texas, Florida, Hawaii, and the United States Virgin Islands. They live around rivers and ponds, often in trees that overhang the water.

Status The Iguana iguana is not on the IUCN Red List for Endangered Species.

Description A full grown Green Iguana is probably the largest lizard in the Americas. They are generally 4 to 5 feet long(1.2m to 1.75m), though some can reach up to 7 feet (2.4m). The tail makes up over half of this length and is sometimes up to 3 times the length of the body. They can drop their tail if need be and it will re-grow. They have strong legs and heavy claws on long toes. With the second and third toe much longer than the others, they can grip trees branches and climb.

Common Green Iguana hatchlings have a bright green coloration, however this fades to a dull green with a tinge of blue on the head as they mature. Depending on the geographical region from which the iguana came, the total size, length, color, patterning, and even head configuration will vary from one Green Iguana to another.

  • Mature iguanas from the more southern parts of their range can be bluish in color.
  • Some from the Caribbean islands can range from green to lavender, black, and even pink
  • Iin the western region of Costa Rica they can be red
  • In northern ranges like Mexico they can be orange.
  • El Salvador Iguanas babies can start out a bright blue, though the color fades as they mature.

Their coloration and patterning can change, similar to chameleons but slower, and this helps them hide from predators. They will shed approximately four times per year with their skin flaking off in bits and pieces.

Green Iguanas have a dewlap, which is a flap of skin under their chin. They also have a row of large flexible spines running down their back, from the nape of their neck to the tip of their tail. Males have higher spines and longer dewlaps than females and develop larger jowls. Green iguanas tongues are short and thick, their eyes have round pupils, and they have eyelids.

Green iguanas will live about 10 years in the wild, and between 10 to 15 years in captivity.

Note: It had long been thought that the Gila Monsters and the Beaded lizards, in the Family Helodermatidae, were the only venomous lizards. But more recently it has been discovered that a couple other groups of lizards also contain venomous lizards including some in the Family Iguanidae, like the Green Iguana. For pet owners there is no reason for undue concern, however, as the toxin secreting glands of these lizards are smaller than those of snakes. The venom they produce may aid to subduing small prey, but on a human it would have no effect, or very little. It is said that a bitten hand might throb at most.

Other Iguana Types:

  • Spiny-tail Iguana (Black Iguana) - Ctenosaura spp.
    Spiny-tail Iguanas require more protein than the Green Iguana, they will eat such things as raw meat, rodents, insects, and raw eggs. They are found in Mexico south to the Panama.
  • Desert Iguana - Dipsosaurus dorsalis.
    The Desert Iguana is more difficult to keep in captivity due to its high temperature requirements that it needs to maintain digestion. They are found in the South Western United States, Mexico and the Islands in the Gulf of California.
  • Chuckwalla - Sauromalus spp. (six species).
    Chuckwallas are very adaptable to captivity as juveniles, but not as adults. Found in the South Western United States, Mexico and the Islands in the Gulf of California.
  • Rhinoceros Iguana - Cyclura cornuta.
    Very large ground dwellers, require very large areas for maintenance. Eat berries and bananas as well as mice and baby chicks. Found in the Greater Antilles, Bahamas and Virgin Islands.
  • Rock Iguana - Cyclura Nubila.
    Rock Iguanas are found in Puerto Rico.
  • Club-tail Iguana - Hoplocercus spinosus.
    The Club-tail Iguana is difficult to keep alive in captivity, but will eat mealworms and termites.
  • Galapagos Marine Iguana - Amblyrhynchus cristatus.
    This iguana is difficult to keep alive in captivity. They are protected, and not available.
  • Galapagos Land Iguana - Conolophus subcristatus.
    The Galapagos Land Iguana has a diet that is similar to the Green Iguana, except it need additional salt. Endangered, not available.
  • Fiji Island Iguanas - Brackylophus spp. (two species, Fiji and Tonga Island groups).
    Endangered, not available to hobbyists.

Food and FeedingA temperature of 88{deg} F is necessary for these lizards for them to effectively digest their food. Each Green Iguana will need about three good meals per week. They are primarily herbivores when they reach adulthood and they have a microbial fermentation in their hind gut which allows them to digest and extract essential nutrients from their foods.
Being a creature of habit, they will eat in the same place every time and will eat out of a bowl. They need fresh water daily and their water dish needs to be about 1" deep (deeper as the iguana grows) and be large enough for the iguana to also bathe in.

A young iguana will eat fruits and vegetables as well as proteins: crickets, grasshoppers, mealworms, earthworms, pinkies, birds, reptiles, and snails. As they grow older, their diet will shift to an almost completely vegetarian diet.

Many bright green and yellow vegetables are very good. Offer lettuces sparingly as they don't have much nutritional value. and preferably offer Romaine. Spinach too should be used sparingly as it is known to bind up calcium. Other types of vegetables should make up the bulk of your offering.


Vitamin and mineral supplements are important in moderation. A two to one Calcium/Phosphorus supplement is a must for all Iguanas, though a fully developed adult will need less than a growing iguana. Monkey chow is a good supplement for young Iguanas, but must be limited to once a week for an adult as too much of it can cause other health problems. These supplements are readily available at your pet store.

HousingAn Iguana is preferably housed alone accept to breed, but they can be housed with another Iguana if there is a plenty of room and they are of similar size. Sometimes larger Iguanas will dominate the food supply and you should always watch for overly aggressive behavior.

Get as large a home to start with as you can. Though a young Iguana can be started in a 10 gallon glass terrarium they will grow but soon need a much larger home. A 20 to 30 gallon glass terrarium works up through the 2nd year and a 40 to 100 gallon glass terrarium up to adulthood.

A full grown Green Iguana would need a minimum size home that is 5' x 5' x 3'. They must not feel cramped or closed in or they may stop eating. They are arboreal ( tree climbing), so a heavy limb is good for climbing on. They need a hiding place to feel secure. Use only artificial plants as they will eat real ones.

Iguanas should be fed from a bowl so they don't ingest any ground material, and a good size water dish will provide a place for soaking and drinking.

Temperature and Lighting requirements:

They do well at 85{deg}- 90{deg}F (29.4{deg}- 32.2{deg}C) in the daytime and 70{deg}-75{deg}F (21.1{deg}-26.7{deg}C) at night. Fluorescent full spectrum reptile lighting or direct unfiltered sunlight is absolutely necessary for your iguanas well being and its long-term maintenance (glass windows filter out necessary rays so putting your iguana in the window does not work to get the required full spectrum lighting).

You will need a basic heat source which can be provided by number of different methods and sources. Additional heat can also be provided for nighttime heating. See Reptile Care:Heating. for a description of heating/lighting. Be sure you use a thermometer so you don't let the terrarium become overheated or under heated!

Cage CareCage maintenance is an important part of keeping reptiles healthy, and long-lived. Reptiles being kept in a confined area as pets need to be protected from harmful micro-organisms and parasites. The reptile cage needs daily and weekly maintenance. Check on a daily basis to make sure that the tank is clean.

Everything you put into their home should be washed and disinfected weekly. This includes dishes and cage decor. All of the substrate should be changed every three to four months. Never clean with a phenol such as Pine Sol. Chlorine and alcohol based cleaners are tolerated much better, but need to be thoroughly rinsed.

Behavior A healthy Iguana needs about a half an hour of supervised activity each day. They are tree climbers as well as excellent runners, swimmers, and divers. One wonderful benefit of a Green Iguana as a pet is that it can be house trained to a newspaper.

Iguanas do have a natural fear of dogs and other "dog" type animals. Their main defense when they are feeling threatened is to whip with their tail, and they can drop there tail (autonomy) if they need to. Other natural defenses are to remain completely motionless or they can extend their dewlap to increase there apparent size to ward off enemies.

Males and females have similar temperaments in terms of being pets, though a male will extend its dewlap when establishing its territory or to show off to a female. Generally Iguanas become more docile the longer they are in captivity.

Handling Always support your iguanas legs and abdomen when you pick it up. First hold its head with the forefinger and index finger of one hand. Then hold its body underneath with your other hand palm up. Move the fingers of your second hand up, under and around the iguana's head. This will then free up your first hand to start gently rubbing the top of its head. The rubbing motion will cause your iguana to close its eyes.

Working with your pet in this manner for about an hour a day for a week or so will help make a pet you can handle. You can consider it a tame iguana when it ceases trying to bite and whip with its tail. It's a good idea to wear heavy clothing when you first start handling it.

Reproduction Green Iguanas become sexually mature between the ages of 2 and 3. In February, a pregnant female will lay up to 30 eggs in a nest of wet sand, burying the eggs 2 to 6 feet deep. Each egg is about 1 1/2 inches long and 3/4 of an inch in diameter. The eggs hatch in April or May, about 16 1/2 weeks later, and the baby Iguanas dig their way up to the surface. The hatchlings are only about 8"(20.3 cm) in length.

Diseases: Ailments/TreatmentsThe most common problems encountered with Green Iguanas are: parasites such as ticks and mites, mouth rot, respiratory disease, injuries, vitamin deficiencies, cool temperatures and drafts. All of these can be avoided with proper care and a good, clean environment.

Availability: Green Iguanas are readily available. At one point, they were becoming scarce in the wild due to over harvesting, so most iguanas in the pet industry today are imported from farms and Iguana ranches in their native countries.


Author: Clarice Brough CRS
Lastest Animal Stories on Green Iguana

Brooke schneider - 2014-09-25
My son lives with his grandma and he left me to take care of his iguana Godzilla and the other day I had him our on our Dec at our new house and he went in the grass and loved it and run across the street and up a tree and cannot find him in the tree and he won't come down I feel so bad thank God my son is asenior I tried the water dish down at the tree base and food to it is going to get cold

Julie Saumur - 2014-08-06
I have a green iguana and she's beautiful love her to death I spoil her and talk to her and she listens to me. I had her for 5 years and she's so healthy and she loves her apples,broccoli,and kale. Then her actual food that smells like fruity pebbles lol. But other than that she's amazing and funny. One time me and my husband watched a pats game and we upset about the other team and she stuck up her middle finger at the team we laughed so hard and it was cute.

Valencia - 2009-01-18
I'm posting this because I hate going into a pet store and seeing the iguanas eating calcium covered lettuce. A store clerk saying "Yes they are easy pets" and there's always a kid there thinking they can get an iguana and just feed it lettuce with a calcium supplement sprinkled on it. Iguanas are a high maintenance pet due to their diet. As a kid, my first iguana died shortly after bringing it home from the pet store, probably due to a poor diet (Yes, I was told they just eat lettuce with the calcium supplement). After doing a lot of research, I bought two more. Even after feeding one of my girls a variety of fresh fruit and veggies and the calcium supplement, I still had to take her to the vet and found out she was calcium deficient. I ended up having to give her calcium shots daily, and then making changes to her diet. She turned out to be a healthy sweet girl who I enjoyed owning. Another false statement that I hear in a lot of pet stores is that iguanas only grow as big as their cage or aquarium. That's another lie. I started off with a decent sized aquarium, which my girls quickly got too big for. So I bought a bigger aquarium, which they quickly out grew. I ended up having to build a giant cage that was the size of a walk-in closet. I still think they are beautiful animals, but a little high maintenance.

  • Laura - 2013-06-21
    I agree with you Valencia. Years ago I purchased a little green iguana for my daughter.I had had anoles in the past. Turned out to be a bad move. Ihad done little research. I took good care of the Iguana we named Gilly. He lived w/ us for years. He went from being about 6' long to over 3 ft long. He was beautiful, but even w a very large custom made cage 6ft x 3 ft x 4 ft...he still did not have enough room. After trying for a year, I finally found someone at the local herptalogical society to adopt him. Gilly moved to St Louis to live in a large space. Now I know why Hey West Florida is being over run w/ giant iguanas. They are hard to keep, they get huge and mine was not very tamed and tried to whip me w/ his tailif I tried to pick him up. I really 'loved' him, but I knew my home was not enough for him, in the large living space he had. He scared the heck out of my 2 dogs, one German Shepard and a poodle. Considering his size, sharp beack, razor like nails and strong whiplike tail, we just couldn't all get along.
Kristie Mansfield - 2007-06-20
I like your site and find valuable information here, but would like to update some information concerning the green iguana that could be harmful.
Iguanas are 100% foliavores throughout their whole lives. The only protien that they ever eat is an occasional insect ingested by mistake.
Contrary to out-dated information, juvenile diets are not different than the adult diet.

Iguanas require a specialized diet when kept in captivity.
The most common illness of the captive iguana is Metabolic Bone Disease (MDB) caused by an improper diet and/or lack of UVB and Vitamin D3. Calcium cannot be metabolized without it.

The food that you give your iguana, on average, should contain about twice as much calcium as phosphorus.
This ratio is very important for bone growth and maintenance, as well as for muscle contraction and many other important bodily functions. Metabolic bone disease, as well as many other health problems can be caused simply by ignoring this ratio for a short length of time.

Another danger is feeding your iguana foods that are high in oxalic acid (such as spinach, beets, beet greens, banannas, celery stalk or swiss chard). Oxalic acid binds with the calcium in these vegetables, rendering it unusable. Rhubard is deadly.

Most captive iguanas die in their first year because of calcium deficiencies. Please educate yourselves extensively before getting an iguana, and please adopt unwanted pets, rather than getting a juvenile.

  • anne dooley - 2013-01-21
    I was told that you should give young igunas wax worms for it helps them fatten up when they are not feeling unwell.