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

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.

An article published in the June 30, 2008 issue of The Proceedings of the National Academy of Sciences documents a heretofore unknown vertebrate life-history strategy…2/3 of the Labord’s chameleon’s life is spent within the egg.

Native to southwestern Madagascar, this tiny lizard lives for only 4-5 months, after an incubation period of 7-9 months.  The entire life cycle is synchronized to an extraordinary degree, with nearly all members of the species hatching, breeding and dying in concert.  Uniquely for a lizard, no adults survive until the next generation hatches…all individuals hatch in November, mate in January, and die shortly thereafter.  The time period from conception to death – usually less than 1 year – is perhaps the shortest known for any vertebrate.

Researchers are trying to identify the genetic or hormonal process that regulates the lifespan.  An understanding of this phenomenon may point to ways of controlling cell death in humans.

You can read about field research projects dealing with this and related chameleons at:

http://www.madagasikara-voakajy.org/en/reptiles_and_amphibians

Recent studies at Australia’s Melbourne University have now brought us back to square one. Although the foregoing information holds true, it seems that at least 1 species, Smith’s dwarf chameleon, Bradypodium taeniabronchum, does indeed specifically change its color to match its background when threatened. Not only that, but it also tailors the degree of change to the specific predator. When faced with a sharp-eyed predator such as a bird, the lizard’s color changes to match the stick upon which it rests perfectly. Less well-sighted animals, such as snakes, elicit a less-perfect camouflage.

It seems that color change exacts a heavy toll, physiologically, on the chameleon. This is likely the reason that it does not employ “perfect” camouflage unless forced to do so by the nature of its enemy.