Home | Lizards

Category Archives: Lizards

Feed Subscription

Contains articles and advice on a wide variety of snake species. Answers and addresses questions on species husbandry, captive status, breeding, news and conservation issues concerning lizards.

Monitor Lizards as Pets: Dumeril Monitor Care and Natural History

The Dumeril’s or Brown Rough-Necked Monitor (Varanus dumerilii) is still collected from the wild, but captive breeding is increasing, and will, I hope, soon be the rule rather than the exception. Although the black and orange hatchlings are hard to resist, Dumeril ownership should not be entered into lightly. Strong and active, adults may top 4.5 feet in length, and are best reserved for those with adequate space and experience. That being said, Dumeril’s Monitors are reputed to be somewhat easier to handle than other similarly sized species. My own experience bears this out, but individual personalities vary greatly…caution and respect for their powerful jaws and sharp claws is a must. For those up to it, this is definitely a species worth considering, as it is little studied in the wild and unprotected across much of its range (and a very interesting creature as well!).

 

Dumeril's Monitor

Uploaded to Wikipedia Commons by Katerina Zareva, EERC Sofia Zoo

Description

The Dumeril’s Monitor sports a “typical” monitor build and averages 3-4 feet in length, with some individuals approaching 5 feet. Hatchlings and very young individuals are brilliantly clad in black and orange. Adults are attractively-marked in various shades of brown and tan. Extremely sharp claws (even by monitor standards!) assist it in climbing.

 

Range

The Dumeril’s Monitor is found across a huge range that extends from southern Myanmar and Thailand through western Malaysia and much of Indonesia to Singapore. The population on Singapore was long believed extinct, with no reported sightings since 1935. However, a single individual was collected in the island’s Nee Soon Swamp Forest in 2008, spurring hopes that it is still hanging on there.

 

Typical habitat

Uploaded to Wikipedia Commons by Tho nau

Habitat

The Dumeril’s Monitor inhabits lowland forests, coastal mangrove swamps and swamp forests. Village and farm outskirts are sometimes colonized, but the effects of habitat development on this species have not been studied. It is at times highly arboreal, but also frequently forages on the ground and in the shallows of rivers and swamps.

 

Enclosure

Like most of their relatives, Dumeril’s Monitors are quite active, and will not thrive in close quarters. Adults require custom-built cages measuring at least 6 x 4 x 6 feet.

 

Cypress mulch or eucalyptus bark may be used as a substrate. Shy by nature, they are best provided with numerous caves, cork bark rolls and hollow logs in which to shelter, and stout climbing branches for climbing. Some individuals prefer sheltering above ground (wild individuals reportedly utilize tree hollows), so a cork bark roll or large nest box positioned among the branches would be ideal. A water bowl large enough for soaking should always be available…the ideal Dumeril’s enclosure would feature a large, drainable pool.

 

The cage should be located in a quiet, undisturbed area of the home, as Dumeril’s Monitors are very aware of their surroundings, and easily stressed.

 

Temperature

Dumeril’s Monitors fare best when afforded a temperature gradient of 78-85 F; nighttime temperatures should not dip below 75 F. The basking site should be kept at 110-120 F. Incandescent bulbs may be used by day; ceramic heaters or red/black reptile “night bulbs” are useful after dark.

 

Provide your monitor with the largest home possible, so that a thermal gradient (areas of different temperatures) can be established. Thermal gradients, critical to good health, allow reptiles to regulate their body temperature by moving between hot and cooler areas. In small or poorly ventilated enclosures, the entire area soon takes on the basking site temperature.

 

t243860Humidity

Humidity should average 70-85%, but dry areas must be available. A commercial reptile mister will be helpful if your home is especially dry.

 

Light

While there is some evidence that UVB exposure may not be essential if the animal is fed properly, I always provide it to monitors in zoo exhibits and at home. In most situations, UVB exposure is the safest option. If a florescent bulb is used (Zoo Med bulbs are 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.

 

Fiddler crabs

Uploaded to Wikipedia Commons by Melongal

Diet

The few available studies indicate that wild Dumeril’s Monitors take a wide variety of prey animals, including grasshoppers, roaches, and other large insects, frogs, crabs, snails, bats, rodents and other small mammals, birds and their eggs, turtle eggs, and fish. Populations living in mangrove swamps seem to favor crabs and snails…in my experience, crabs and crayfish always elicit a vigorous feeding response from captives.

 

Hornworm (sphynx moth larvae)

Uploaded to Wikipedia Commons by Shhewitt

I do not use a rodent-only diet for these or other monitors from similar habitats (i.e. the Black Rough-Necked Monitor). Youngsters should be fed largely upon roaches, super mealworms, earthworms, snails, hornworms and other invertebrates, along with small whole fishes, un-shelled shrimp, fiddler and green crabs, crayfish and squid. Pinkies or small mice may be provided once weekly, and hard-boiled eggs can be used on occasion. All meals (other than fishes, crabs and rodents) offered to growing monitors should be powdered with calcium, and a high-quality reptile vitamin/mineral supplement should be used 3x weekly. I favor ReptiVite and ReptiCalcium.

 

Rodents and whole fish can comprise 50% of the adult diet, with a variety of large insects, earthworms, hard-boiled eggs, crayfish, crabs, shrimp, snails, and similar foods making up the balance. Calcium and vitamin/mineral supplements should be used 1-2x weekly. Large food items should be avoided; even where adult monitors are concerned, mice are preferable to small rats.

 

Temperament

Although not a species for beginners, Dumeril’s Monitors adjust well to captivity when given proper care, and make fine, long-lived pets. Initially shy, some learn to trust gentle caretakers, while others – especially wild-caught individuals – remain wary. A large, well-furnished cage will provide the security that is essential if they are to become approachable.

 

In common with all monitors, they are capable of inflicting serious injuries with their powerful jaws, long tails and sharp claws. Thick leather gloves should be worn when handling Dumeril’s Monitors, as even tame individuals leave deep scratches with their claws in the course of their normal movements.

 

Breeding

A single male can be housed with 1 or 2 females, but they must be watched carefully. The nesting area should be enclosed (i.e. a large tub or plastic storage container within a wooden box equipped with an entrance hole) and stocked with 2-3 feet of a slightly moist mix of sand, top soil and peat moss.

 

We have a good deal to learn about captive reproduction. Success (and failure) has been reported under a wide variety of conditions. Please post below for detailed information on pairing adults and incubating the eggs.

 

Please check out my posts on Twitter and Facebook. Each day, I highlight breaking research, conservation news and interesting stories concerning just about every type of animal imaginable. I look forward to hearing about your interests and experiences as well, and will use them in articles when possible.

 

Please also post your questions and comments below…I’ll be sure to respond quickly. Thanks, until next time, Frank Indiviglio.

 

Further Reading

 

Monitor Ownership: Important Considerations

Monitor Learning Abilities

 

The Best Substrate for Crested Gecko Terrariums: Avoiding Impactions

Crested Gecko

Uploaded to Wikipedia Commons by annakilljoy,

It wasn’t so long ago that one had to search through many books to find a photo of a Crested Gecko (Correlophus ciliatus), and seeing a live individual in a zoo was impossible. In fact, the species was presumed extinct in the early 1990’s! Today, these bizarre New Caledonian natives are captive bred in huge numbers, and are popular with reptile keepers worldwide. However, while their husbandry needs are well-understood, and rather easy to meet, substrate choice can be problematic. Judging by questions I’ve received lately and feedback from my zookeeper colleagues, intestinal blockages (“impactions”) caused by substrate ingestion are an important concern.

 

Coconut Husk: Good and Bad Points

Coconut husk, the most commonly recommended Crested Gecko substrate, has a down side. I’ve had great success using this product at home and in zoo exhibits housing tarantulas, centipedes, millipedes, land crabs, beetles and other invertebrates. However, it is commonly swallowed by reptiles and amphibians during the course of feeding – more often, it seems, than occurs with other substrates. Coconut husk has been implicated in most of the Crested Gecko impactions I’ve recently been informed of.

 

Leaping gecko

Uploaded to Wikipedia Commons by Alfeus Liman

As is the case for other sometimes troublesome substrates, many keepers use coconut husk for Crested Geckos without incident. How do we explain this? Through discussions with veterinarian colleagues at the Bronx Zoo, I’ve learned that there are many variables which affect the passage of foreign materials through the body. The nature of the diet (and, of course, the swallowed material), hydration levels, calcium intake (calcium assists in muscle contractions, which may be needed to expel ingested substrate), general health and vigor and many other factors are involved. It seems best to err on the side of caution.

 

My Top Pick for Naturalistic Terrariums

I favor a mix of topsoil and sphagnum moss as a substrate for Crested Geckos and for many other species as well. Perhaps because of the size or consistency of the moss strands, sphagnum seems rarely to be ingested. I’ve successfully kept a great many amphibians and some reptiles on sphagnum moss alone. Moss that is taken into the mouth is, in the incidents I’ve observed, easily expelled.

 

Soil seems like it “should be” troublesome, but that has not been my experience…I hope to look into the reasons for this in the future. I use soil collected from wooded, pesticide free areas, but you can also purchase bagged “organic” or “chemical-free” soil. Be sure to avoid products that contain white Styrofoam-like spacing material.

 

By using roughly 2 parts soil to 1 part sphagnum moss, you can achieve a mix that holds moisture well and does not easily become compacted. This also serves as an ideal planting medium for many live plants…and Crested Geckos truly come into their own in complex, well-planted terrariums.

 

Sow Bugs

Uploaded to Wikipedia Commons by Pudding4brains

I often establish colonies of sowbugs, millipedes, springtails and other leaf-litter invertebrates in terrariums with moist substrates; earthworms can also be used if temperatures are not too high. In addition to aerating the soil and consuming feces, dead leaves, and shed skin, sowbugs and others make healthful additions to the diets of many herps.

 

The Base Layer

Zoo Med Hydroballs, preferably but not necessarily covered by a layer of plastic screening, should be used as the base layer of your Crested Gecko terrarium. They are a bit more effective than the broken clay flower pots favored by us dinosaurs in assisting with drainage, preventing soil impaction, and maintaining high humidity levels.

 

Washable Terrarium Liners

Those seeking an extra measure of safety may wish to consider terrarium liners. Potted plants camouflaged with rocks or sphagnum moss can be used to create a naturalistic effect.

 

I’ll address the specifics of Crested Gecko care and breeding in the future; until then, please post any questions or observations below.

Hi, my name is Frank Indiviglio. I’m a herpetologist, zoologist, and book author, recently retired from a career spent at several zoos, aquariums, and museums, including over 20 years with the Bronx Zoo.

Please check out my posts on Twitter and Facebook.   Each day, I highlight breaking research, conservation news and interesting stories concerning just about every type of animal imaginable. I look forward to hearing about your interests and experiences as well, and will use them in articles when possible.

 

Please also post your questions and comments below…I’ll be sure to respond quickly. Thanks, until next time, Frank.

 

Further Reading

New Caledonian Giant Gecko Care

Choosing the Best Substrates for Reptiles and Amphibians

Sailfin Dragon Care and Conservation: a Zookeeper’s Notes

H. pustulatus

Uploaded to Wikipedia Commons by MKFI

Sailfin Dragons (4 species in the genus Hydrosaurus) are among the most spectacular of all the world’s lizards. Even after a lifetime of working with reptiles in zoos and the field, the sight of one stops me cold – and I know of no herp enthusiast who reacts otherwise. While certainly not suitable for beginners, the experienced keeper with ample space will be hard pressed to find a more exciting prospect. And with a new species recently described, and wild populations of others in jeopardy, serious attention to captive breeding is urgently needed.

 

Description and Natural History

The Philippine Sailfin Lizard, Hydrosaurus pustulatus, was the species most commonly seen in the pet trade until the mid-1990’s, when exports were restricted. Stoutly built and sometimes nearing 4 feet in length, males are clad in green, neon purple, and reddish blue, and bear huge crests along the back and tail. DNA studies of individuals in Manila animal markets revealed that 2 genetically-distinct species are currently classified as H. pustulatus. The newly-described species has not yet been named. Please see the article linked below for further information.

 

Sailfin habitat

Uploaded to Wikipedia Commons by Ramon FVelasquez

The Amboina Sailfin, H. amboinensis, native to Indonesia and New Guinea, now often appears in pet markets in the Philippines. Weber’s Sailfin Lizard, H. weberi, is limited in distribution to the Indonesian islands of Ternate and Halmahera.

 

Sailfin Dragons are found near water, frequenting forested river edges, swamps, and coastal marshes.

 

Behavior

Sailfin Dragons are alert and somewhat high-strung. Pets will flee from noises, cats, dogs, large birds and other threats. Injuries during such escape attempts are common. While some calm down and accept gentle handling, wild caught individuals may remain unapproachable for years.

 

Female

Uploaded to Wikipedia Commons by Adrian Pingstone

Status in the Wild

A recent survey by University of Oklahoma herpetologists (Biological Conservation, V 169, Jan, 2014) revealed that only 10% of the Philippine Sailfin Dragon’s remaining habitat is protected. The rest is impacted by logging, coastal fisheries, illegal collection, and other activities.

 

The Terrarium

Sailfin Dragons forage on the ground but are otherwise arboreal. They will be stressed if kept in low enclosures that do not allow climbing opportunities.

 

Youngsters may be raised in 30-55 gallon aquariums. In common with Asian Water Dragons and Basilisks, they often run along the glass and are prone to snout and jaw abrasions. Cardboard or other solid borders along the lower 3-4 inches of the tank’s sides will help to limit such injuries.

 

Larger individuals must be housed in custom-made cages. A single adult will need a home measuring approximately 5 x 4 x 5 feet. More height – 6 feet or so – is ideal. In suitable climates, predator-proof outdoor enclosures, including pre-fabricated bird aviaries, can be fashioned into “luxury accommodations”.

 

H. amboinensis

Uploaded to Wikipedia Commons by Cburnett

Numerous wide, stout branches and shelves should be provided. Sturdy live plants (Pothos, Philodendron, Spider Plants) and/or artificial plants should be added to provide a sense of security. Wild Sailfin Dragons always live near heavy cover, and will be ill-at-ease in bare terrariums. One or two sides of the enclosure should be solid as opposed to screened, again to place the animals at ease (this is standard in zoo exhibit construction – many animals fare poorly when open to view from all directions). Never position rocks below branches, as startled individuals may jump to the floor and be injured.

 

A water bowl large enough for bathing must be provided. Custom built cages with filtered pools are ideal.

 

Substrate

The substrate should be capable of holding moisture and soft enough to cushion falls when hungry or frightened Dragons leap to the ground. Cypress mulch is ideal; soft sphagnum moss can be added if falls are frequent. Avoid fine substrates such as peat and coconut husk, which tend to lodge around the eyes and jaws.

 

Light

Sailfin Dragons will not thrive without a source of UVB radiation. Natural sunlight is best, but be aware that glass and plastic filter out UVB rays, and that fatal overheating can occur very quickly. If a florescent bulb is used (the Zoo Med 10.0 UVB Bulb is ideal), be sure that all animals can bask within 6-12 inches of it. Mercury vapor bulbs broadcast UVB over greater distances, and provide beneficial UVA radiation as well. A 12:12 hour day-night cycle should be maintained.

 

Heat

The ambient air temperature should range from 80-90 F, with a basking spot of 110-120 F; night-time temperatures can dip to 75 F.  Incandescent bulbs should be used to maintain these temperatures. Provide your pets with the largest enclosure possible, so that a varied temperature gradient can be maintained. A ceramic heater or red/black reptile “night bulb” can be used after dark.

 

Humidity

Sailfin Dragons require humidity levels of approximately 80%, and the chance to dry off as well. The terrarium should be misted twice daily. Large bathing pools and reptile misters can be used to increase humidity.

 

Companions

Males are territorial and will fight savagely. Females often co-exist, but may also battle for dominance.

 

Crayfish

Uploaded to Wikipedia Commons by Thomas Seip

Feeding

Sailfin Dragons need a varied diet. Those fed crickets and mealworms alone quickly develop serious developmental disorders. Whole vertebrates such as minnows, shiners, crayfish or small bait crabs, and pink mice represent the best means of meeting their high calcium requirements; use goldfishes only sparingly, as a steady diet has been implicated in health problems in other reptiles. Pink mice should be fed less often than fishes (once each 7-14 days), and furred rodents are best avoided.

 

Roaches, earthworms, crickets, butterworms, silkworms, super mealworms and other commercially-available insects, should be offered regularly. In order to increase dietary variety, try canned grasshoppers, snails and silkworms. Cicadas, beetles, grasshoppers, moths and other wild-caught insects should be provided as well; please see the article linked below for further information on safely collecting insects.

 

Young Sailfin Dragons are primarily carnivorous, but add greens and fruit to the diet as they mature. Captives, however, often reject non-living foods. Mixing live mealworms into a bowl of kale, dandelion, squash, carrot, mango, peaches and other produce may encourage them to sample the salad.

 

Depending upon the type of food, Sailfin Dragons can be fed daily, every-other-day or thrice weekly; young fare best when fed frequently. Food (other than vertebrates) should be powdered with Zoo Med ReptiCalcium or a similar product. Vitamin/mineral supplements such as ReptiVite should be used 2-3 times each week.

 

While ingested substrate is usually passed, food is best offered in bowls to limit potential problems.

 

Health Considerations (Pet Owner and Pet)

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 write me for links to useful resources.

 

Unfortunately, captive breeding remains the exception rather than the rule. Wild-caught individuals will be afflicted with various parasites and should be seen by an experienced veterinarian shortly after acquisition.

 

Sailfin Dragons are prone to snout and jaw injuries that result from rubbing against glass and screening. Wounds may become infected, and should be treated immediately.

 

Fine/gritty substrate may lodge along the gums and in the eyes.

 

Hi, my name is Frank Indiviglio. I’m a herpetologist, zoologist, and book author, recently retired from a career spent at several zoos, aquariums, and museums, including over 20 years with the Bronx Zoo.

Please check out my posts on Twitter and Facebook.   Each day, I highlight breaking research, conservation news and interesting stories concerning just about every type of animal imaginable.

 

Further Reading

 New Sailfin Dragon Species Found in Pet Market

Feeding Insectivorous Lizards

 

Pet Lizards: Large, Small, and Colorful Insectivores

Rainbow Whiptail

Uploaded to Wikipedia Commons by DiverDave

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

Uploaded to Wikipedia Commons by Charlesjsharp

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

Uploaded to Wikipedia Commons by B kimmel

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

Uploaded to Wikipedia Commons by Haplochromis

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.

 

Hi, my name is Frank Indiviglio. I’m a herpetologist, zoologist, and book author, recently retired from a career spent at several zoos, aquariums, and museums, including over 20 years with the Bronx Zoo.

Please check out my posts on Twitter and Facebook.   Each day, I highlight breaking research, conservation news and interesting stories concerning just about every type of animal imaginable. I look forward to hearing about your interests and experiences as well, and will use them in articles when possible.

 

Please also post your questions and comments below…I’ll be sure to respond quickly. Thanks, until next time, Frank.

 

Further Reading

The Best Diets for Insect-Eating Lizards

 

How to Breed Swifts and Spiny Lizards

Monitor Lizard Ownership: Important Points to Consider

Lace monitors fighting

Uploaded to Wikipedia Commons by John Hill

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.

 

Crocodile Monitor

Uploaded to Wikipedia Commons by Greg5030

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.

 

Water Monitor

Uploaded to Wikipedia Commons by Beijingbing

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.

 

Nile Monitor

Uploaded to Wikipedia Commons by A. C. Tatarinov

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.

Hi, my name is Frank Indiviglio. I’m a herpetologist, zoologist, and book author, recently retired from a career spent at several zoos, aquariums, and museums, including over 20 years with the Bronx Zoo.

Please check out my posts on Twitter and Facebook.   Each day, I highlight breaking research, conservation news and interesting stories concerning just about every type of animal imaginable. I look forward to hearing about your interests and experiences as well, and will use them in articles when possible.

 

Please also post your questions and comments below…I’ll be sure to respond quickly. Thanks, until next time, Frank.

 

Further Reading

Monitor & Rhino Iguana Learning Abilities

 

Black Rough Neck Monitor Care

 

 

Scroll To Top