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

Bent-toed geckos (Genus Cyrtodactylus, i.e. C. louisiadensis and C. irianjayaensis) are becoming ever more popular in captivity but, while a fascinating group, their care is often fraught with difficulties, and there is a great deal of conflicting information being circulated. A recent note from blog reader Dave, upon whom I can always count for interesting comments and questions, brought these wonderful creatures to mind again.

Dave noted the scarcity of husbandry information regarding bent-toed geckos, and mentioned that his lizard, purchased as a giant bent-toed gecko, was not feeding with very much vigor. Following are some exerts from my response to Dave, along with a few additional notes.

The Genus Cyrtodactylus
So far, 115 species have been described in the genus Cyrtodactylus. The giant bent-toed gecko is often sold as the “New Guinea phase” of C. louisiadensis, but is actually a separate species, C. irianjayaensis. To further confuse matters, stores sometimes mix up the various species, and coin their own names.

There are still many questions as regards the husbandry and natural history of the giant bent-toed gecko. Over the years, I’ve had a number of little known species of the same genus (Cyrtodactylus) pass through my hands, and have found the following general principles to be of use.

The Importance of a Secure Environment
Give the animal as much space as possible, with lots of cover and places to climb…suspended pieces of rolled cork bark make perfect shelters. Bent-toed geckos are very stress-prone, but don’t always exhibit the behavioral signs of stress – flight, panting, threat displays – so commonly seen in other lizards; disturb it as little as possible. These are definitely animals to observe, not handle. A night-viewing bulb will allow you to watch the lizard as it goes about its nocturnal wanderings without undue disturbance.

Providing Security
One useful technique that works with animals of all types is to provide a solid wall or two. You may notice that well-run zoos rarely exhibit animals in cages having all sides are open to view.

In an aquarium, you can cover some of the glass with dark paper or cardboard. Even where shelters are available, this simple step often makes a great difference in the animal’s welfare, and brings about immediate changes in its behavior.

Next time I’ll cover lighting and feeding, including a note on the use of snails in the diet of this and related geckos.

Further Reading
A listing of all species with the genus Cyrtodactylus, along with range information, may be found at
http://www.jcvi.org/reptiles/search.php?submit=Search&exact%5B%5D=genus&genus=Cyrtodactylus

The image pictured above  was referenced from Wikipidia and features a related species; not the Giant Bent Toed Gecko. Originally posted by W.A. Djatmiko.

Released and escaped green iguanas (Iguana iguana) have now established huge populations in southern Florida. Although I must admit to a certain degree of fascination with introduced species, there can be no doubt that the massive lizards have caused a great many problems in their adopted environment.

An Impressive but Bothersome Invader
Normally arboreal, iguanas adapt to treeless environments by commandeering burrows occupied by the endangered burrowing owl (Athene cunicularia), displacing the birds and destroying eggs and chicks in the process. Ever hungry, the 4-6 foot long behemoths also assist the spread of undesirable invasive plants by eating their fruits and dispersing the seeds in their feces.

Among one of their most troublesome characteristics is a propensity to colonize airway strips and nearby areas. Green iguanas in Puerto Rico have caused runway accidents, and they are considered a collision hazard in Florida airports as well.

Raccoons in Cities and Nature Preserves
Raccoons, although native, have also become problematical in recent years. Now well adjusted to people, they thrive everywhere…during my years as a nuisance wildlife trapper, I caught scores throughout NYC, including in some of Manhattan’s most densely-populated neighborhoods.

Raccoon populations in south Florida parklands reach 250 animals per square kilometer – 200 times the densities of those dwelling in natural habitats! In addition to serving as a reservoir for rabies and distemper, raccoons in Florida pose a serious threat to the nesting success of green, loggerhead and other marine turtles.

Please check in next week to see how a well-planned control program for both iguanas and raccoons went astray…and would up helping the iguana population to grow astronomically!

Further Reading
Iguanas make fascinating pets, but, as males may exceed 6 feet in length, they are not for the unprepared. Please read our cage guide, Green Iguanas, before you take on one of these impressive giants. Green Iguana image referenced from Morguefile.

Panther chameleons (Furcifer pardalis) carefully regulate exposure to sunlight in accordance with their Vitamin D3 levels, states an article published in the May/June issue of Physiological and Biochemical Zoology.

Nutrient Levels Affect Behavior

Chameleons with high Vitamin D3 levels (achieved through a diet of vitamin-supplemented crickets) limited their exposure to the sun, while those maintained on a vitamin-poor diet maximized basking time.  Further analysis showed that, as regarded individual Vitamin D3 levels, the lizards were “…as effective as mathematically possible” in achieving optimal sun exposure.  Vitamin D3 receptors in the brain are believed responsible for accessing vitamin needs and controlling basking behavior.

Basking or Diet?

I was most interested in this article because, although this point was not specifically addressed, it established that panther chameleons can be provided with adequate Vitamin D3 (at least in the short term) through dietary means.  I have long questioned my observations that certain reptiles, typically thought to be entirely dependent upon UVB radiation (basking) for Vitamin D synthesis, are none-the-less sometimes able to obtain sufficient Vitamin D3 from their diets (please see the article referenced below).

Some Cautions

Information of the type established by this research has a way of taking on a life of its own once spread via the internet, so a few words of caution are in order.

Please bear in mind that the Vitamin D and UVB needs of reptiles vary widely from species to species, and perhaps even within populations of the same species.  This research applies to a single species housed outdoors with access to full sunlight, and should not be used as other than a baseline for further experiments as regards other animals.

For now, it remains important to provide the heliothermic (basking) reptiles that you keep with an appropriate UVB bulb  (or natural sunlight) and to use vitamin/mineral supplements  judiciously.  This is a quite important topic, and one fraught with misinformation…please write with questions concerning individual reptiles.

Further Reading

For information on an outstanding UVB bulb and recent tests concerning its output, please see my article on Zoo Med UVB Lamps.

I have written about related experiences with day geckos and red-eared sliders… please see my article Has Anyone Observed This?  for further details.
Image referenced from Wikipedia and originally posted by Tom Junek.

 

In both captivity and nature, chameleons (Family Chamaeleonidae) stand alone – unique in so many ways, they are truly marvelous creatures to know and care for.  Today I would like to highlight a few unusual facts about these favored reptile pets.

Cultural Significance

Chameleons have long drawn our attention…in fact, their fossilized remains have been found alongside proto-human skeletons in Tanzania’s Olduvai Gorge.  Throughout Africa and Madagascar, they were regarded as somewhat mystical creatures, spying on people with their oddly-shaped eyes and reporting back to the deities about our (many!) shortcomings.

Fortunately, most of these beliefs also prohibited people from harming chameleons, and even today there are those who will risk a car accident rather than run one over.

Diversity

To date, 178 chameleon species have been described.  The smallest (pygmy leaf chameleons, Genus Brookesia), barely reach 1.5 inches in length while the family’s giant, Oustalet’s chameleon (Furcifer oustaleti) may be 30 inches or more from nose to tail tip.

Range and Habitats

Chameleons reach their greatest diversity in Madagascar.  They are also found in coastal North Africa, Africa south of the Sahara, along the western edge of the Middle East and the northern shores of the Mediterranean and in India and Sri Lanka.  Two species have been introduced to Mexico and the USA.

Often regarded as rainforest animals, chameleons have also adapted to dry forests, deserts, mountainous areas (where they endure snow) and city parks.

Moving About

Chameleons walk with a peculiar rocking motion, designed to help them blend in with swaying leaves and branches…indeed, some species are reluctant to move unless a slight breeze is blowing.

In most species, the tail may be held straight out for balance, curled around a branch as a “fifth hand” or coiled tightly during dominance displays.  Chameleons in free-fall have been observed to latch onto branches with the tail, halting their descent!

The Amazing Tongue

I could go on for a long time about chameleon tongues (fear not, I’ll contain myself!), as the surprise of first seeing one in action some 3 decades ago is still fresh in my mind.  It is certainly one of nature’s most spectacular food-gathering innovations, and completely unique to this magnificent group of lizards.

The tongue is hollow and fits over a cartilaginous (bone-like) tube known as the hyoid spike.  Depending upon the species, it may be slightly shorter than or greatly exceed the chameleon’s body in length.

The tongue is projected out towards prey by powerful accelerator muscles, and tendons attaching its base to the hyoid spike cushion the shock of impact.  Once the tongue is on its way, the chameleon can only control the length of the strike…aiming is done beforehand.

Surprisingly, the tongue’s tip is not only sticky but also very abrasive…both qualities, along with a skin flap that flips over the hapless victim, assure that few meals escape.

Retractor muscles pull the tongue back into place.  These are quite powerful, allowing the lizard to reel in prey weighing half as much as itself.  Armed in this manner, large chameleons take quite large insects, and even small birds and rodents on occasion.

Further Reading

Chameleon reproductive behavior is among the lizard-world’s most complex.  The abstract of an interesting research project is posted at http://cat.inist.fr/?aModele=afficheN&cpsidt=13694591.

 

 

Chameleon fanciers are indeed fortunate that the chameleon best suited for captivity, the veiled or concave-casqued chameleon (Chamaeleo calyptratus) is also among the most beautiful and interesting of the group (it is also pathologically anti-social, but so are most of its relatives!).  Turquoise, emerald green, yellow and tan, each in many shades, all find a place in this lizard’s repertoire of color changes.  Male veiled chameleons approach 2 feet in length while females top out at about 14 inches.

The Casque

The bony, 3-4 inch high casque (helmet-like structure) that crowns the male’s head gives the species its alternative name of “concave-casqued chameleon”.  The casque of the female is much smaller.

In addition to conferring the impression of greater size upon its owner – an important consideration in territorial disputes – the casque functions as a water condensation surface.  Water gathering on the casque is funneled to the chameleon’s mouth by movable skin flaps, aiding survival in the dry habitats in which this species dwells.

Chameleon Cages

Ample space and ventilation are key in successfully keeping veiled chameleons.  Weather permitting, heavily-planted outdoor cages are the ultimate in chameleon homes.  Our outdoor aviaries are perfect …housing chameleons in this manner also offers the best chance of breeding success.  Our large screen cages and terrarium top add-ons are ideal for indoor maintenance.

Feeding Veiled Chameleons

Dietary variety is an absolute must when it comes to keeping even the hardiest of chameleons, and the veiled is no exception.  A diet restricted to crickets and mealworms will lead to your pet’s early demise.  The main portion of their diet should be comprised of roaches, crickets, mealworm beetles, super mealworms, butterworms, waxworms, silkworms and tomato hornworms (these last two now available via internet dealers).

Canned Insects

Veiled chameleons also readily accept canned insects from plastic feeding tongs.  Grasshoppers, silkworms and others should be used frequently to increase dietary variety.

Wild-Caught Insects

All chameleons become “nutritionally bored” over time, and most eventually refuse once-favored foods that are offered continually.  With that in mind, I consider wild-caught insects, collected from pesticide-free areas, to be an essential element of chameleon husbandry.  Zoo Med’s Bug Napper  is an excellent insect trap.

Sweeping a net through tall grass and searching around outdoor lights will also yield a wide variety of tasty treats…katydids, grasshoppers, cicadas, moths, butterflies, beetles, caterpillars and other insects will all be eagerly accepted.

Nutrient Loading Feeder Insects

Food insects should themselves be given a nutritious diet before being offered to your pets.  Please see my article Prepared Diets and Food Supplements for House Crickets  for further information.

Leaves and Flowers….for a chameleon?

Oddly for a species belonging to a family of such highly-evolved predators, the veiled chameleon consumes a good deal of vegetation.  Favored plant foods include dandelion (flowers and leaves), Ficus, romaine and the flowers of Nasturtium and Hibiscus.

Vitamins and Minerals

Adults fed a varied diet require a vitamin/mineral supplement  once or twice weekly; the food of growing chameleons should be supplemented 3-4 times each week.

Further Reading

An interesting article on feral veiled chameleons in Florida is posted at http://www.naherpetology.org/pdf_files/208.pdf.