That Reptile Blog – Reptile, Amphibian and Exotic Pet Care and Information

The Green Iguana (Iguana iguana) is truly a study in contrasts.  Captive-bred by the millions on farms in Latin America, the 7-inch-long hatchlings are widely considered to be suitable for novice reptile keepers.  Indeed, with proper care, they mature into one of the most impressive and responsive of all reptilian pets.  Yet these tropical lizards have very specific needs that must be met if they are to thrive, and their eventual size (4-6 feet) and potentially aggressive behaviors are serious considerations.

Range and Habitat

The Green Iguana’s range extends from southern Mexicothrough Central America to Paraguay. They also inhabit Puerto Rico, St. Lucia and other Caribbean islands, and have been introduced to Florida and Hawaii (please see this article on Iguana-Raccoon Interactions in Florida).

Green Iguanas are always found near water, into which they plunge when frightened. They are often associated with forested areas, so I was surprised to encounter large populations in Venezuela’s treeless llanos region; please see this article.

Behavior

Green Iguanas are ever-alert, and easily startled by noises, dogs and other threats. They vary greatly in personality – some become docile, while others remain wary of people.

Males may become dangerously aggressive with during the breeding season (please see article below), and either sex may bite, lash out with the tail, or scratch.  The wound on my arm, pictured in the attached photo, resulted from a single flick of the tail (and my skin is generally described as “very leathery”!).  Please write in for information on safe handling.

Housing

Setting up the Terrarium

Enclosure size is a major concern.  Hatchlings will exceed 2 feet in length in their first year, and 3 feet by age 2.  Adults reach 4.0 to 5.5 feet in length, with males sometimes exceeding 6 feet.

Hatchlings may be started in a 30 gallon aquarium, but will need a 55 gallon tank within 12 months.  Once your lizard reaches 3 feet in length, a homemade or commercial cage will be necessary.  An enclosure measuring 6 x 3 x 6 feet tall will suffice for an adult; wheels should be added to allow for sun exposure.  Predator-proof outdoor cages such as modified bird aviaries are the ultimate in “luxury accommodations”.

Green Iguanas are highly arboreal and will be stressed if kept in enclosures that do not allow climbing opportunities.  Stout branches and wooden shelves should be provided.

If an “iguana proof” room is available, out-of-cage exercise time can add greatly to your lizard’s quality of life.

Substrate

Cypress mulch has been used with success, but impactions due to substrate ingestion are possible.  Newspapers, washable cage liners or outdoor carpets are preferable.

Females without access to suitable nesting sites may retain their eggs; please see this article for information on captive breeding.

Light

Green Iguanas will not thrive without a source of Ultra-Violet B light.  Natural sunlight is best, but be aware that glass and plastic filter out UVB rays, and fatal overheating can occur very quickly.

If a florescent bulb is used (the Zoo Med 10.0 UVB Bulb is ideal), be sure that your pet can bask within 6-12 inches of it.  Mercury vapor and halogen bulbs broadcast UVB over greater distances, and also provide beneficial UVA.

Heat

The ambient air temperature should range from 82-95 F, with a basking spot of 95-100 F.  Incandescent bulbs should be used to maintain these temperatures.  A ceramic heater or red/black night bulb can be used after dark.

Humidity

Green Iguanas favor humidity levels of 65-75%, but must be able to dry off as well.  The terrarium should be misted as needed.  A reptile humidifier may be used in especially dry environments.

A large water bowl should be provided for drinking and soaking.

Companions

Males will fight savagely, and females may also battle for dominance.  Juveniles usually get along, but must be watched carefully as they mature.

Feeding

Strict attention to diet is essential if you are to succeed with Green Iguanas.  Nutritional deficiencies can develop quickly, and are difficult to treat. Young iguanas should be fed daily; 2 small meals are preferable to 1 large.  Adults can be fed every-other-day, or provided smaller daily meals.

Greens, Vegetables and Fruit

The majority of your iguana’s food – 60% or more – should consist of a variety of fibrous, calcium-rich vegetables such as kale, romaine, dandelion, bok choy, collards, mustard and turnip greens, beet tops and escarole; broccoli, peas, squash, beans, carrots, peppers and mixed frozen vegetables may be added in smaller quantities.  Spinach binds calcium and should be avoided.

Fruit should not comprise more than 10% of your iguana’s diet.  Bananas, pears, apple, figs, melons, berries, kiwi, peaches and others should be offered.

Boiled brown rice or fiber-rich, sugar free cereals (i.e. Fiber One) may be given as a fiber source. This may not be necessary if a variety of fibrous greens are provided, but serves well as “insurance”.

Protein

In their natural environment, young Green Iguanas consume both insects and vegetation before switching to a plant-based diet as they mature.  While success has been had by using insects as a protein source for young iguanas, most keepers are better off relying upon legumes, such as boiled lentils or pinto, navy and kidney beans.  These should make up 5-10% of the diet until age one, after which time they can be used as occasional treats.

A number of commercial iguana diets are available.  While their long-term use as a sole diet has not been studied, adding some to your iguana’s salad should provide additional nutrients.

Supplements

Most meals provided to growing iguanas should be powdered with a Calcium source such as Zoo Med ReptiCalcium.  Reptivite or a similar vitamin/mineral supplements should be used 2-3 times each week.  The supplementation needs of adults vary; please write in for further information.

Health Considerations

Due to their size, Green Iguanas are sometimes allowed to wander at will about the home.  While a room that has been carefully set up for your iguana (please write in for details) can be useful, free-ranging iguanas present serious health and safety risks.  Chief among these are the potential for fires (dislodged lamps, etc.) and an increased risk of Salmonella transmission.  Please write in for further information. Read More »

Drawn by uneaten food, shed skins and other organic material, ants sometimes become pests around reptile, amphibian and invertebrate collections. As pesticides are harmful to humans and other creatures alike, eliminating ants in areas used by pets and people takes some care.  Today I’d like to highlight a substance that I used with great success in various zoos, and which works equally well at home – diatomaceous earth.

A Most Formidable Insect

Famed entomologist E.O. Wilson has demonstrated that ants “rule” many habitats, driving evolution and other processes to a degree that is hard to imagine.  What little work I’ve done with them has convinced me that they are, at the very least, extremely resourceful creatures. When working with Leaf Cutter Ants (Atta cephalotes) at the Bronx Zoo, I observed a dramatic increase in egg production shortly after empty nesting chambers were added to the colony’s enclosure – the workers somehow communicated to the queen that more space was available, and more bodies were needed. This likely holds true for other species as well – killing a few dozen workers will not reduce ant numbers but instead may set up a call for more eggs! Read More »

The Senegal Chameleon (Chamaeleo senegalensis) has long been common in the pet trade, yet there remain significant roadblocks to longevity and breeding. I recently re-read a 1990 study on prey choice in this species. I then considered it in light of newer research that established a link between Vitamin D levels and chameleon basking behavior. I believe both contain important findings that may be applicable to many species.

“What, grasshoppers again”!

In the study that examined prey choice in Senegal Chameleons (J. of Herpetology: V.24, N.4: p.383), different groups of chameleons were fed solely on either Long-Horned Grasshoppers or House Crickets. Over a period of several days, those lizards feeding upon crickets showed a strong preference for grasshoppers, and those on grasshopper-only diets favored crickets.

I have also observed this in other chameleon species under my care at the Bronx Zoo, and in a variety of reptiles and amphibians. As long as the species is acceptable, novel prey usually causes a very strong feeding response. Indeed, zookeepers and hobbyists commonly say that captive herps “become bored” with crickets, mealworms and other staples. Read More »

Almost every zoo building in which I’ve worked was home to roach (2-3 species) and House Cricket populations.  In most, pesticide use was not an option. An older animal keeper whom I befriended let me in on his favorite insect pest control technique – the molasses trap.  He was content to let management wonder how he did such a good job so, out of respect for him, I did not share the secret until he retired. Then, for a time, molasses traps became standard in several zoo buildings. Molasses is also useful in outdoor traps, where it never fails to turn up a variety of interesting species. I’ll expand on that below as well.

Pesticide Problems

House Crickets, roaches and other escaped “feeder insects” can be problematic in private collections. In the damp basements favored by amphibian keepers, Spotted Camel Crickets (Ceuthophilus maculatus, please see photo) may also set up housekeeping. These unusual creatures are very interesting in their own right, and I’ve featured them, and a large African relative, in several exhibits. However, most folks find their size, appearance and jumping abilities quite unsettling (please see comments in the article linked below – insect fans will find them very interesting!). Read More »

Tortoises are highly prized by reptile fans. They are extremely responsive, quickly recognizing those who feed them, and readily learn from experience. Unfortunately, new owners are often unaware of their very specific care requirements, and many fail to thrive. Given the precarious state of their wild populations, it is unethical to keep these amazing animals unless you are fully prepared to meet their needs. Please write in for further guidance.

The Bronx Zoo’s collection was very “tortoise/turtle oriented” during my tenure, and I had the good fortune to work with dozens of species both there and in the field. From rare Flat-Tailed (Pyxis planicauda) and tiny Egyptian Tortoises (Testudo kleinmanni) to 500 pound Aldabra and Galapagos Tortoises, each brought challenges and new lessons. Hopefully, what I’ve learned will be of benefit to other keepers, and to the spectacular animals in which they are interested.

The following information can be applied to the care of a variety of species. However, details will vary; please write in for information on individual species.

Natural History

Fifty-three tortoise species roam the grasslands, deserts and tropical forests of Africa (where they reach their greatest diversity) North and South America, Europe, and Asia.

All tortoises live on land and feed mainly on vegetation. They range in size from the 4-inch-long Speckled Padloper (Homopus signatus) to the 500+ pound Aldabra and Galapagos Tortoises.

Housing

Setting up the Terrarium

Tortoises need far more room than most folks imagine. Only the smallest, such as Spectacled and Russian Tortoises, can be accommodated in commercial cages. Adults generally do best in enclosures that have been constructed with their needs in mind.

Glass aquariums are unsuitable (please see this article). Respiratory problems may develop due to insufficient ventilation, and space will usually be a concern. Also, aquariums rarely allow for the establishment of a thermal gradient.  Thermal gradients, critical to good health, allow tortoises to regulate their body temperature by moving between hot and cooler areas.

Outdoor maintenance is possible in suitable climates. Please write in for details.

Plastic-based rabbit cages are preferable to aquariums, but most tortoises will outgrow these in time. Cattle troughs can also be modified as tortoise homes.

This Table Top Tortoise Terrarium is an ideal enclosure for many species. The Zoo Med Tortoise Home can be expanded with additional units, and is well-worth investigating.

Substrate

“Playground” sand is suitable for Radiated, Leopard and other tortoises native to arid environments. An equal amount of sand and topsoil can be used for Yellow-Footed Tortoises and other forest dwellers.

Although impactions due to swallowed sand and soil are rare, it is best to provide food in large bowls so that ingestion is limited.

The substrate should be deep enough to allow your tortoise to dig a shallow pallet (sleeping depression) at night. Dry grass clumps can also be provided as shelter.

Light

Tortoises need daily exposure to high levels of UVB light. Natural sunlight is best, but be aware that glass and plastic filter out UVB rays, and that fatal overheating can occur very quickly.

Use a high-output UVB bulb (the Zoo Med 10.0 Bulb is ideal), and position the basking site within 6-12 inches of it.Mercury vapor and halogen bulbs broadcast UVB over greater distances, and provide beneficial UVA radiation as well.

Heat

Most tortoises require a basking site of 90-95 F, but must be able to move into cooler areas (75-88 F) as well.  Incandescent heat bulbs should be used to maintain these temperatures; red/black night bulbs or ceramic heater-emitters work well after dark.

Humidity

Desert and grassland tortoises develop health problems in damp enclosures, but low humidity has been associated with growth abnormalities in several species. Please write in for details.

Travancore Tortoises and other forest-dwellers need access to moist and dry areas.

Companions

Females and youngsters often co-exist, but must be watched as dominance hierarchies will develop. Males will fight, and often harass females with near-constant mating attempts.

Feeding

A great deal of conflicting information has been published on the subject of nutrition, and confusion concerning this critical aspect of tortoise husbandry is common. Unfortunately, small dietary mistakes will translate into major health concerns in short order.

Grassland and Desert Tortoises

Grassland and desert species (i.e. Russian, Greek, Spurred and Pancake Tortoises) have evolved to consume a diet that is high in fiber and calcium and low in protein, fruit and fat. In the wild, grasses and herbaceous plants are their primary foods. Beans, dog food and other protein sources should be avoided, and fruit limited to an occasional treat. Honeysuckle, dandelion, clover and other native grasses, weeds and flowers can make up the bulk of the diet when available; please see this article http://blogs.thatpetplace.com/thatreptileblog/2009/07/29/tortoise-diets-mediterranean-species-and-russian-horsfield%E2%80%99s-tortoises/ for further information.The balance may consist of greens such as kale, endive, Swiss chard and romaine; avoid spinach and iceberg lettuce. Zoo Med’s Grassland Tortoise Diet http://www.thatpetplace.com/natural-grassland-tortoise-food may be added to salads. Hay (but not Timothy) should be provided to Spurred and Leopard Tortoises.

Rainforest Tortoises

Rainforest natives, such as African Hinge-backed, Yellow and Red-Footed Tortoises, require a diet rich in a wide variety of leafy greens, fruits, and vegetables. A small weekly meal of moist cat food, along with canned http://www.thatpetplace.com/pet-supplies-search#!Reptile-Supplies/reptile-food&ea_c=feeder-insects or live snails, earthworms and super mealworms, will satisfy their protein requirements.

Vitamin, Minerals and Water

The calcium requirements of all tortoises appear to be quite high. Food should be powdered with Zoo Med ReptiCalcium with D3 or a similar product. A Vitamin/mineral supplement such as Reptivite with D3 should be used 2-3 times weekly.

Water should be available, but damp conditions present a health hazard. A twice-weekly 15 minute soak should be provided if water bowls are routinely tipped, or if your tortoises seem not to be drinking regularly.

Other Feeding Considerations

High protein diets have been associated with “pyramiding” and other growth deformities in several species.
Adults can be fed 5-7 times weekly, juveniles daily.

 

Further Reading

NY Turtle & Tortoise Society Seminar (Galapagos Tortoises, others)

Turtle Conservancy Newsletter: Ploughshare Tortoises mating

Tortoises Learn by Imitation

Radiated Tortoise videos and info

Flat Tailed Tortoise image referenced from wikipedia and originally posted by Mark Pelligrini
Greek Tortoise image referenced from wikipedia and originally posted by Derek Coetzee
Yellow-footed Tortoise image referenced from wikipedia and originally posted by Geoff Gallice