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

The world’s astonishing lizard diversity – 5988 species have been described to date – is mirrored by the huge array of species now available to reptile enthusiasts. In recent years, refined husbandry and breeding techniques have introduced and re-introduced many fascinating lizards to the pet trade. Today I’d like to cover several that might interest folks with varying degrees of experience. I’ll review others in the future…until then, please post notes about your own favorites below, as those mentioned here are just a small sample.

 

Important Notes

A highly-varied diet is essential if you are to have success in keeping insectivorous lizards. Crickets and mealworms alone, even if powdered with supplements, are not an adequate diet for any species.

 

Always provide your lizards with the largest possible enclosure. Large terrariums will simplify the establishment of a thermal gradient (areas of different temperatures). Thermal gradients, critical to good health, allow lizards to regulate their body temperature by moving between hot and cooler areas.

 

Few diurnal (day-active) lizards will thrive without a source of UVB light.  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 bulbs broadcast UVB over greater distances, and provide beneficial UVA radiation as well.

 

The following information is meant to provide an overview. Please post below for more detailed information.

 

Emerald Swift, Sceloporus malachiticus

Also known as the Green Spiny Lizard, mature males are breathtaking even by lizard standards. Note the Latin species name – malachite green, with a blue tint, best describes these beauties. Although many in the trade are wild-caught, captive births (they bear live young) are becoming more common. Emerald Swifts range from southern Mexico (Yucatan) through Central America to Panama, and are restricted to cloud forests and similar mountainous habitats.

 

Unfortunately, as with most habitat specialists, care can be somewhat complicated. Emerald Swift terrariums must be kept rather cool and humid (74-76 F, humidity 60-70%), but hot, dry areas (90 F) must also be available. As airflow is important to their health, the screen top should not be covered with plastic as a means of increasing humidity; rather, a reptile fogger, or frequent hand-misting, should be employed.

 

A pair might get by in a 30 gallon terrarium, but a 55 gallon, which will also support a second female, is preferable. Driftwood and rocks should be supplied for climbing and basking; all rocks should be placed on the tank’s floor, not on the substrate, so that tunneling lizards will not be crushed. UVB exposure is essential. A highly-varied diet comprised of well-fed, calcium and vitamin-supplemented roaches, crickets, butterworms, waxworms, calciworms, silkworms, hornworms and wild caught insects is critical for their long-term health. Like most related lizards, Emerald Swifts are high-strung and should be viewed as pets to observe rather than handle.

 

Long Tailed Grass Lizard, Takydromus sexlineatus

This active, attractive lizard is also sold as the Asian Grass or Six Lined Grass Lizard. Originally available only as wild-caught imports, they have proven to be prolific breeders, with multiple clutches per year being common. Their huge natural range extends from India and China through most of Southeast Asia to Indonesia. Long toes and an extraordinarily-long tail (an individual with a 2.5 inch long body will sport an 8 inch tail!) enable these little acrobats to hunt in the “canopy” of their grassland home – a niche unavailable to other lizards.

 

Although small, Grass Lizards are very active. A trio should be provided a 20 long to 30 gallon terrarium. If given sufficient space and cover, a small group can be maintained together; success has also been reported in housing them with small geckos, treefrogs and anoles. The terrarium should be well-stocked with real and artificial plants and branches, as they are stressed in bare enclosures.   UVB exposure is essential, and a temperature gradient of 72-85 F, with a basking site of 90-95 F, should be established.  A diet comprised of as many insect species as possible must be supplied; crickets and mealworms alone are not adequate.

 

Sudan Plated Lizard, Gerrhosaurus (Broadleysaurus) major

This thickly-built lizard appears quite formidable, but it is actually calm in demeanor, and usually becomes a most responsive pet. Also a long-lived pet – a pair under my care at the Bronx Zoo was still actively-courting at age 25+. The “Sudan” part of this lizard’s name is misleading, for its enormous range extends from that country clear across the width of Africa, and south along the continent’s western coast to South Africa. “Plated” is, however, apt, as they sport very sturdy, thick scales. Sudan Plated Lizards favor semi-arid scrub, brushy savannas and lightly-wooded grasslands, and may also colonize parks and other developed areas.

 

Plated Lizards really come into their own in large enclosures, and should not be considered unless a cage of at least 4’ x 3’ x 3’ (and preferably larger) is available. Those I’ve kept in large zoo exhibits were doing something interesting all day long…the same cannot be said for the many poorly-housed specimens I’ve seen over the years. They prefer to bask on rocks, and are inveterate diggers. Be sure to place all rocks on the terrarium’s floor, not on the substrate, or a lizard may tunnel beneath one and be crushed. A deep layer of sand and gravel should cover the cage bottom; PVC tubes and similar shelters make great retreats. Plated Lizards do well at a temperature gradient of 76-88 F and with a basking site of 95F. Ample UVB exposure is essential.

 

Providing a varied diet to these ever-hungry lizards is a simple matter, as little will be refused. Mine relished the cicadas, crayfish and may beetles, along with all of the standard feeder insects. Interestingly, they also take earthworms, which are rejected by most arid-adapted lizards. An occasional pink mouse can be offered, but rely primarily upon supplements rather than vertebrates as a calcium source (wild individuals do take the occasional small lizard or snake, but they are mainly insectivorous). Fruit is accepted by many individuals, but they seem to do fine without it.

 

 

 

Further Reading

The Best Diets for Insect-Eating Lizards

 

How to Breed Swifts and Spiny Lizards

Each of the many monitors under my care at zoos and in my own collection has left me with the feeling that they are somehow “more complicated” than other reptiles. Recent research into their breeding and hunting strategies bears this out…monitors do indeed appear to be the most advanced of all lizards. Pets often become unusually responsive to their owners, who sometimes ascribe mammal-like qualities to these fascinating reptiles.

 

Among the monitors we also find the world’s largest lizards, a fact which adds to their allure. But giants such as the Water, Lace, Crocodile and Nile Monitors are tough to manage even in zoos, and are suitable only for those few keepers with the knowledge, space, maturity and finances to meet their needs. More importantly, it must be understood that all monitors can inflict severe injuries…in fact, fatalities are a real possibility where young children or incapacitated adults are concerned. Today I’ll review some important points that, if considered beforehand, will greatly improve life for both monitor and monitor owner. As always, please be sure to post any questions or thoughts below.

 

Safety

While monitors vary greatly in personality – some become rather docile, while others remain wary of people – all can be dangerous and must be treated with caution. They are certainly capable of learning from experience and altering their responses to people. My experiences in zoos with Crocodile and Water Monitors illustrated this very clearly to me (please see articles linked below). However, this should not lead us to “trust” them, or to treat a monitor, or any reptile, as though it were a well-trained dog. The following quote from legendary snake expert Bill Haast is generally applicable to any reptile: “You can have a snake for 30 years, but leave the cage open once, and it’s gone – and it won’t come back unless you have a mouse in your mouth”!

 

Large species such as Crocodile, Water, Lace and Nile Monitors (V. salvadorii, V. salvator, V. varius and V. niloticus) can be dangerously aggressive and are not suitable for most private collections. In the course of my work as the Bronx Zoo’s head mammal keeper, I helped restrain giraffes, bison, polar bears, rhinos and many other formidable beasts…but Water Monitors are, pound-for-pound, one of the strongest animals I’ve ever handled. Large monitors can inflict severe bites and scratches, which can lead to permanent injuries and life-threatening infections. Operating policies in most zoos require that 2 experienced keepers be present when monitor exhibits are entered.

 

Space

Monitors are quite active, and languish in cramped enclosures. Also of concern is the fact small cages render it difficult to establish a temperature gradient (thermal gradients, critical to good health, allow reptiles to regulate their body temperature by moving between hot and cooler areas). Most species require very high basking temperatures, and if sufficient space is not provided, the entire cage will become over-heated due to the effects of the basking site.

 

The 6 to 7 foot-long Nile, Lace, Crocodile and Water Monitors require room-sized enclosures with drainable pools. Even moderately-sized species, such as the Rough-Necked Monitor (V. rudicollis), should be provided with a living space measuring 6’ x 6’ x 6’ or greater.

 

Expenses

The initial purchase price of your pet and the expenses involved in constructing a custom-built enclosure are only a small portion of the total cost involved in monitor ownership. Electricity use will be substantial, veterinary care is as or more expensive than for a dog, and food (mainly rats and, for some, whole fishes) continues to climb in price.

 

Veterinary Care

Reptile-experienced veterinarians are difficult to find in many regions, and not all will be willing or able to treat a large monitor. Trust me – it is a grave mistake to embark on monitor ownership before locating a veterinarian, or to imagine that even the hardiest of species will not require medical care. Please post below for a list of herp-experienced vets in your area.

 

Time Commitment

While all reptiles require daily checks as to their condition, many require very little in the way of actual daily or even weekly work. Large monitors need a great deal of care, usually on a daily basis…think more in terms of an annoying puppy (sorry, dog-people!) with dangerous teeth and claws rather than a well-fed, oft-fasting Ball Python.

 

Remember also that monitors may live into their 20’s, and that the amount of work and degree of expertise they demand usually complicates the task of finding appropriate care while you are away from home.

 

 

Further Reading

Monitor & Rhino Iguana Learning Abilities

 

Black Rough Neck Monitor Care

 

 

Bearded Dragons (Pogona vitticeps) are among the most popular of all reptile pets and a great choice for both new and experienced lizard enthusiasts.  But apparently-healthy specimens sometimes refuse to feed, or lose weight despite feeding, and there is still much confusion as to why this occurs.  My work with Bearded Dragons and hundreds of other lizards in zoos and at home has (I hope!) provided me with some useful insights into this problem.  When presented with a non-feeding Bearded Dragon, we must check our husbandry protocol (UVB, temperature, etc.) and investigate the possibility of a disease or injury. Other potential problems, such as the effects of circadian rhythms (“internal clocks”), may be less obvious, yet very important.

Is My Lizard Hibernating?

Hibernation (or brumation) is not the neat, tidy process I learned about as a child – there are varying degrees of dormancy. Depending upon where they live within the natural range, wild Bearded Dragons may experience severe winters, and will become dormant for several months each year. However, those in milder regions may remain active (please see the article linked below to read more about their natural history).

Pets sometimes cease feeding in the fall, despite being provided with 12-14 hours of daylight and high temperatures.  Although all Bearded Dragons in the US pet trade are several generations removed from the wild, the tendency to hibernate may persist.  “Internal clocks”, or circadian rhythms, can cause pets to become lethargic and refuse food during the winter.  To confuse matters further, some reptiles enter dormancy when winter arrives in their native habitats…even if it happens to be summertime in their present home!  I’ve seen this among captive Indian Gharials (fish-eating crocodiles) and other reptiles.

The Bearded Dragon Habitat

Bearded Dragons vary in their response to crowding.  Moving your pet to a larger terrarium may help, and this will also make it easier for you to establish a thermal gradient. Thermal gradients, which allow reptiles to move from hot to cool areas, are critical to good health. A 30 gallon long-style aquarium is the minimum size that should be considered for an adult…a 55 or larger is preferable.

Inappropriate temperatures will cause your lizard to slow down its feeding, and will impair digestion. An incandescent spotlight bulb should be used to create a basking site of 100-110 F. The rest of the terrarium should be kept at a temperature range of 72-85 F.

 

Like all desert-dwelling diurnal lizards, Bearded Dragons require high UVB levels. If a florescent bulb is used (Zoo Med’s models are excellent), be sure that your pet can bask within the distance recommended by the manufacturer. Mercury vapor bulbs broadcast UVB over greater distances, and provide beneficial UVA radiation as well.

Diet

Wild Bearded Dragons feed upon a huge array of plants, invertebrates, and the occasional small lizard, snake or rodent. A diet comprised only of crickets, mealworms and a simple salad will not support good health long term. Offering different types of insects can also incite new interest in feeding.  We see this most commonly in chameleons, but the enthusiasm your Bearded Dragons will show for novel foods will leave you with no doubt as to their value.

Please see the articles linked below to read more about adding silkworms, house flies, sow bugs, wild-caught insects and other important foods to your pet’s diet. Studies have shown that some lizards will alter their diet in accordance with changing nutritional needs…your pet’s poor appetite may indicate that more variety is needed.

Stress

While female Bearded Dragons usually co-exist, males are intolerant of other males and cannot be kept together. If you keep your lizards in a group, make certain that each is able to bask and to obtain enough to eat. Dominant animals can frighten others even without direct aggression…merely seeing a “bully” in another terrarium may be enough to inhibit an animal from feeding. Appetite-suppressing aggression is also common among young lizards that are being raised in groups.

 

Locating the terrarium in a noisy part of the house, or where there are vibrations from machinery, may also depress appetites and contribute to other health concerns.

 

Disease, Impactions and other Health Issues

An impaction from substrate (swallowed with meals) is one of the more common reasons that Bearded Dragons cease feeding. While many have been successfully kept on sand, others seem to have problems almost immediately. The exact type of substrate used, composition of the diet, calcium intake, hydration levels and many other factors likely play a role in explaining the differences we see. Washable terrarium liners are the safest substrate option.

 

Unfortunately, highly-contagious Atadenoviruses are well-established in US Bearded Dragon populations. These viruses are spread via body contact and improperly cleaned tools; afflicted females may also pass infections along to their young. Some of the illnesses they cause, including Wasting Disease and “Star Gazing”, are accompanied by a loss of appetite and/or weight. Please see the article linked below for further information.

Internal or external parasites, and a host of other less common ailments, should also be investigated if your pet stops eating, or if it feeds but continues to lose weight. Please post below if you need help in locating a reptile experienced veterinarian.

 

 

Further Reading

 

Atadenovirus in Bearded Dragons

 

Hibernation in Bearded Dragons

 

Collecting Insects as Food for Reptiles

Leopard Geckos and Bearded Dragons have stellar reputations among lizard enthusiasts. In fact, they come as close to being perfect pets as any reptile can. However, there are major differences in their habits, activity levels and care needs, and it’s important to be aware of these when choosing a pet. When an animal is active, how much its care will cost, the space it needs and other factors will affect your pet-keeping experience and your new lizard’s quality of life. In the following article I’ll compare Leopard Geckos and Bearded Dragons in all relevant areas. Detailed care information is provided in the articles linked under “Further Reading”; as always, please also post any questions or observations you may have.

Reptile Handling
Most lizards are best considered as “hands-off” pets, but both Leopard Geckos and Bearded Dragons break this rule. Although individual personalities vary, both adapt well to gentle handling, and are not stressed by human contact.

Activity Levels
Neither is overly active, but both have fascinating behaviors that are well-worth watching for. Bearded Dragons are out and about by day, at which time they bask (their most common “activity”!), feed, and display to tank-mates.

Leopard Geckos, being nocturnal, are ideal for owners who are “night owls”. They will become active in a dimly lit room, or you can equip the terrarium with a black or red reptile night bulb (lizards do not sense the light produced by these bulbs). Leopard Geckos sometimes emerge during the day as well, especially if food is offered.

Life Span
A Leopard Gecko in the St. Louis Zoo’s collection lived for a record 28.6 years. The published longevity for a Bearded Dragon is 15 years, but there are unofficial reports of individuals approaching age 20.

Lizard Reproduction
Both species breed reliably, and a wide variety of color morphs are available. Please see the articles linked below for detailed information.

Cost
Bearded Dragons require larger terrariums and higher temperatures than do Leopard Geckos, and must be provided with a source of UVB radiation (Leopard Geckos and other nocturnal lizards get along fine without UVB bulbs). Therefore, Leopard Geckos are the less-expensive pet, in terms of supplies and electricity use.

Terrarium Size (single adult)
Leopard Gecko: 10-20 gallon (larger is preferable)
Bearded Dragon: 30 gallon

Temperature
Leopard Gecko: 72-85 F, with a basking site of 88 F
Bearded Dragon: 75-88 F, with a basking site of 95-110 F

Lizard Diet
Leopard Geckos are carnivorous. Young Bearded Dragons feed largely upon insects, adding plants to the diet as they mature.

Both require highly varied diets comprised of vitamin/mineral supplemented roaches, silkworms, crickets and other invertebrates. Bearded Dragons also need various greens and, perhaps, a high quality commercial food.  Mealworms and crickets alone, even if sprinkled with supplements, are not an adequate diet for either lizard. Please see the articles linked below for more information on diet.

Health Concerns (Pet and Pet Owner)
Intestinal impactions that result from the ingestion of sand and gravel are perhaps the most commonly-encountered health concern (both species). This can be avoided by the use of cage liners, or by feeding your lizards in large bowls, via tongs, or in a separate, bare-bottomed enclosure. Young lizards, being clumsy hunters, are more likely to swallow substrate than are adults.

Diseases related to poor nutrition are common among lizards maintained on crickets and mealworms alone, and in Bearded Dragons that do not receive adequate UVB exposure (Vitamin D3 is manufactured in the skin, in the presence of UVB). Both species sometimes refuse food in the winter, even if kept warm (please see this article for further information).

If a moist shelter is not available, Leopard Geckos sometimes retain the eyelid lining after shedding. Please see this article.

Atadenovirus infections are becoming increasingly common among Bearded Dragons. Unfortunately, the resulting “Wasting Disease” or “Star Gazing” is incurable. Please see this article for further information.

Salmonella bacteria, commonly present in reptile and amphibian digestive tracts, can cause severe illnesses in people. Handling an animal will not cause an infection, as the bacteria must be ingested. Salmonella infections are easy to avoid via the use of proper hygiene. Please speak with your family doctor concerning details, and feel free to post below if you would like links to useful resources.

 

Further Reading

Complete Guide to Bearded Dragon Care

Complete Guide to Leopard Gecko Care

Breeding Leopard Geckos

 

 

Among the world’s 52 species of neon-hued day geckos we find some of the most desirable of all lizard pets.  It’s not easy to stand out among such a spectacular group, but one species does so admirably – the magnificent Giant Day Gecko (Phelsuma grandis).  Although rarely seen outside of its native Madagascar until the mid-1980’s, this largest of all day geckos is now the hands-down favorite of many lizard enthusiasts.  I’m still asked to design zoo and museum exhibits for Giant Day Geckos, despite the fact that public institutions tend to avoid “pet trade species” – their beauty simply cannot be ignored.  The following information can also be applied to the care of 3 other large relatives that were once considered Giant Day Gecko subspecies – the Boehm’s Giant Day Gecko (P. madagascariensis boehmi), the Madagascar Day Gecko (P. m. madagascariensis) and Koch’s Giant Day Gecko (P. kochi).

 

Description

This stoutly-built lizard averages 9-10 inches in length, with large males reaching 12 inches.  Clad in brilliant green and bearing maroon to red head and orange dorsal markings, Giant Day Geckos must be seen to be truly appreciated.  Hobbyists have also developed an array of breath-taking color morphs.

 

Captive Gecko Behavior

All day geckos are best considered as animals to observe rather than handle.  Fast and alert, they will watch as you open the terrarium and may flee if possible; keep a net nearby to catch escapees.  Their tails snap off with the slightest provocation, and the delicate skin tears easily.  Although well-habituated individuals may accept food from tongs, these high-strung beauties are not for those seeking a hands-on pet.  However, the careful keeper will be rewarded with a range of interesting behaviors, regular reproduction and pets that may live into their 20’s.

 

Range and Habitat of the Giant Day

The Giant Day Gecko occurs across much of northern Madagascar, and on several small offshore islands.  Introduced populations are established on several of the Florida Keys (Little Torch, Plantation, Plantation and Big Pine).  It has also been sporadically reported in Florida’s Dade, Lee and Broward Counties, and on Hawaii.

 

Giant Day Geckos evolved in rainforests, but adapt well to some degree of human presence.  In both their native and introduced ranges, they can be seen on building walls and in well-vegetated gardens.

 

The Terrarium

Giant Day Geckos are highly arboreal and must have climbing opportunities.    A 30-55 gallon “high-style” tank will accommodate a pair or trio.  Always opt for the largest enclosure possible.

 

By virtue of their habits and need for security, all day geckos are ideally suited to life in terrariums provisioned with live plants; they will not thrive in bare enclosures.  Plants such as Pothos, Snake Plants and Philodendron will provide visual barriers and a sense of security.  Rolled cork bark and hollow bamboo sections make ideal hideaways and basking, perching, and egg-deposition sites; these should be arranged both horizontally and vertically.

 

Be sure to establish plenty of basking sites near heat and UVB bulbs, as dominant individuals may exclude others from these important areas.

 

Substrate

A mix of potting soil, cypress mulch and sphagnum moss is ideal.

 

Light

Giant Day Geckos should be provided with a source of Ultra-Violet B light.  Natural sunlight is best, but be aware that glass and plastic filter out UVB rays, and that fatal overheating can occur very quickly.  A daytime period of 12-14 hours should be maintained.

 

It appears that at least certain species can utilize dietary D3, and do well without access to UVB.  I’m familiar with one exhibit in which Giant and Standing’s Day Geckos have bred over several generations in the absence of UVB (please see photo of female Standing’s Day Gecko with well-developed calcium reserves, or “chalk sacs”).  However, there are a number of variables to consider…please see the article linked below for further information.

 

Heat

Ambient temperatures of 82-85 F, with a basking spot of 88-90 F, are ideal.  Nighttime temperatures can dip to 76-80 F.

 

Large enclosures will allow for the establishment of a thermal gradient (areas of different temperatures).  Thermal gradients, critical to good health, allow lizards to regulate their body temperature by moving between hot and cooler areas.

 

Incandescent bulbs should be used to maintain temperatures.  A ceramic heater or reptile night bulb can be employed after dark.

 

Humidity

These rainforest-adapted lizards do best when humidity levels range from 50-75%.  Their terrarium should be misted at least twice daily; a mister and hygrometer can be used to increase and monitor humidity if need be.

 

Gecko Companions

Males will fight savagely and should never be housed together. Females are also territorial, and must be watched carefully.  Pairs, trios (1 male, 2 females) and youngsters may co-exist in large enclosures, but be sure to check that all are able to feed and bask.

 

Feeding

A highly-varied diet is essential if you are to have success in keeping any day gecko species.  Crickets and mealworms alone, even if powdered with supplements, are not an adequate diet.

 

The diet should consist of roaches, sow bugs, crickets, butterworms, waxworms, cultured houseflies, silkworms and other commercially available invertebrates.  Feeders should be provided a healthful diet for several days prior to use.

 

If possible, also offer wild-caught insects (avoid pesticide-sprayed areas, and learn to identify stinging and toxic species; please see the articles linked below).  Moths, beetles, grasshoppers, tree crickets, earwigs, “smooth” caterpillars and a variety of others will be accepted. Your pets will definitely show greater enthusiasm towards novel foods!  The Bug Napper Insect Trap will simplify insect collection.

 

The natural diet also includes nectar, ripe fruit, pollen and sap. A mixture of fruit-based baby food, honey or molasses, liquid reptile vitamins, and ReptiCalcium with D3, mixed with enough water to achieve a syrupy consistency, should be offered 3 times weekly.  Experiment with the ingredients, and add a bit of over-ripe papaya, mango and banana on occasion.  Your geckos will prefer to take nectar from cups suspended above-ground.  Please see the article linked below for further information.

 

Important food supplements include Zoo Med ReptiCalcium with D3 or a similar product (most meals) and a vitamin supplement (i.e. ReptiVite) 2-3 times weekly.

 

Day Geckos rarely drink from bowls but will lap water that is sprayed onto foliage.

 

Further Reading

 

Keeping Day Geckos Without UVB Access

 

Collecting Insects for use as Reptile Food

 

Feeding Day Geckos