Monday, February 28, 2011

Green Iguana

Green Iguana (Iguana iguana)


Green Iguanas are native to Southern Mexico, Central America, and many northern countries of South America. Wild populations can also be found in California, Florida and Hawaii. These populations were started by iguanas that escaped from their enclosures or were released by their owners, and which have survived and even bred in their new habitats.

Green iguanas are generally arboreal, meaning that they like to live in trees. Their long claws help them in climbing. They spend the majority of the day high in the forest canopy, and move to the ground only to move from tree to tree, mate, or lay eggs. They are also good swimmers and jumpers.

Green iguanas are very diurnal. This means that they are active during the day and sleep at night. Unlike cats and dogs, which tend to nap on and off during the day and are likely to be up and active when their owners are awake, iguanas wake up in the morning, stay awake the whole day, go to bed in the evening and sleep the whole night through. This is why it is important to provide your iguana with a routine day/night schedule and a quiet, dark place away from household activity to sleep at night.

Iguanas in the wild have a whole host of predators that prey on them. Baby iguanas are prey for jungle cats, birds, turtles and even large fish. Large iguanas are pray for boa constrictors, caimans, hawks and eagles. Adult iguanas in captivity are not at risk from many predators, as they can defend themselves with sharp teeth and strong tails, but eagles and hawks may still try to get to them if you allow them to roam free. If they make it to adulthood, they can be expected to live for 10-15+ years. Males grow to be about 6-7 ft. long while females max. out at 5 ft.. Contrary to popular belief, keeping an iguana in a small enclosure will not hinder an iguanas growth. They will continue to grow throughout their lifetimes – quickly at first, and then slowly as they age.


One of the most difficult things for Iguana owners to provide for their pets is adequately sized housing. A young iguana will outgrow a 50 gal. aquarium in its first year or so. An Iguana enclosure should be at least twice as long as the Iguana. That means that the enclosure for an adult Iguana may need to be up to 14 ft. long! The enclosure also needs to be very tall, because Iguanas enjoy climbing. An enclosure should be at least 6 ft. tall.

Since they are from the tropics and are cold-blooded, iguanas need an enclosure that is kept very warm. You must provide a basking spot that is 90-95ºF, and the ambient temperature should be about 80ºF. Low temperatures prevent iguanas from properly digesting their food and absorbing nutrients. Within the habitat, a range of temperatures should be provided so that your iguana can regulate its body temperature by moving back and forth between hot and cool areas. Humidity levels in your iguana's environment should be 65-75%.

Iguanas must have a source of UV light. UVB, in particular, is important to iguanas because without it their bodies cannot produce vitamin D3, which helps them absorb calcium. Iguanas that are deprived of proper UV lighting suffer from a disease called Metabolic Bone Disease (MBD) which is unfortunately very common in captive iguanas. MBD causes weak bones, jaw and bone deformities and early death.

Also, iguanas are solitary creatures who do not need to be kept with other iguanas. In the wild, the only see each other during mating time. Some keepers have been able to keep females together, or females with one male, others find it difficult.


Iguanas do not commonly drink water, even when they are thirsty and it is offered in a dish. A shallow tub should be provided so that the iguana may soak, but hydration should be maintained through high humidity and moisture acquired from daily feedings of veggies. However, when they do drink water, which is usually only on occasion, they will dip a large portion of their head into the water, lapping up the water under the surface or sometimes they may even lick water droplets off of plants and other misted surfaces.

Many care books say that iguanas can be fed meat, dog or cat food, and insects, but this is not wise. All of these items contain animal protein and can cause severe organ damage and possibly even premature death. While it may be true that wild iguanas occasionally eat animal protein (and this has not been conclusively shown), it is known that iguanas raised on a strictly vegetarian diet not only are large and healthy, but longer-lived than those fed animal protein. So, regardless of what wild iguanas are or aren't doing, there is no good reason to feed meat, and in fact, there are serious reasons not to. In addition to meats and other pet foods, iguanas should never be given dairy, eggs, or rhubarb (which is toxic). Wild flowers and plants should not be given because of the chance that they cold be contaminated by pesticides and acidic fruits, like citrus, are also bad.

Providing a wide variety of good quality foods is also important for a good diet. Iguanas in the wild are known to eat a wide variety of plants and fruits, and iguanas in captivity should have the same opportunity. About half the diet should be dark, leafy greens like collard greens, arugula, kale, mustard greens, dandelion greens (with flower), etc. Some owners tend to feed iguanas iceberg lettuce, which provides iguanas with water but has no other nutritional value. Half should be other veggies, such as green beans, orange-fleshed squashes (butternut, Kabocha), snap or snow peas, parsnip, asparagus, okra, alfalfa (mature, not sprouts), onions, mushrooms, bell peppers, sweet potato, zucchini, yellow squash, carrots. Some fruits can be mixed in, like figs (raw or dried), blackberries, strawberries, raspberries, grapes, mango, melon (cantelope, honeydew, watermelon), papaya, banana, apple.

Green Iguanas also require a calcium and vitamin supplement. This supplement works with the UVB light allowing the lizard to receive the proper amounts of calcium and vitamins. This should be used every day as babies and reduced to 1-2 times a week as adults. Calcium is sold in a powder form and is sprinkled on the vegetables that you feed your Iguana.


These wild Green Iguanas in Ecuador are accustomed to people.

The concern with Green Iguanas is not that their populations are shrinking, but that they are growing too large. This is great for green iguanas, but terrible for local wildlife. Often times, captive-raised iguanas will be ill-prepared for life in the wild and do not survive long. When they do manage to adapt, they disrupt the ecosystem, compete with native species for resources, and prey on species that are not adapted to deal with such predators. In fact, it is illegal to own pet iguanas in the state of Hawaii, because the isolated island ecosystems are so easily disrupted by the introduction on exotic, or non-native species. Despite this, feral populations of iguanas do exist there.

If you purchase an iguana, it is very important that you provide secure housing to prevent escapes, and if it ever becomes the case that you are unable to properly care for your iguana, please do not release it into the wild. It would be better to surrender the animal to a rescue center or another keeper.



1. Give your Iguana a LOT of space, including height.
2. Keep a rigid Day/Night schedule.
3. Feed fresh, leafy greens, with a little non-citrus fruit and calcium.
4. Provide UV, preferably direct sunlight, if weather permits.


1. EVER, EVER, EVER release your Iguana into the wild.
2. Keep your Iguana in an aquarium.
3. Feed meat, or anything with animal protein.

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