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

Today we’ll take another look at those oddest of lizards, the chameleons (Family Chamaeleonidae), followed by some tips on the care of the Senegal Chameleon (Chamaeleo senegalensis).

Eyes

The cone shaped torrents that enclose the chameleon’s eyes are actually made up of fused, overlapping sets of eye lids.  By covering all but the eye’s pupil, they offer excellent protection to this most important organ.

Chameleon eyes contain far more visual cells than do our own, and can be rotated 180 degrees.  Uniquely among all animals, the eyes can focus either independently (on different objects) or together.

Vision, Learning and Hunting Accuracy

When a chameleon focuses both eyes on an insect, it hits its target 9 out of 10 times.  In laboratory situations, accuracy falls to 0 when 1 eye is covered.  However, by the second day hunting accuracy rises to 20%.  On day 4, the one-eyed hunters successfully capture insects on 50% of their attempts.

Senses of Hearing and Smell

Chameleons do not hear well …like snakes, they detect air vibrations and low-pitched sounds only.

The Jacobsen’s organ, which allows many other reptiles to “smell” chemical particles in the air, is vestigial (much reduced) in chameleons.  It is therefore assumed that they do not detect most odors.

Distribution

Madagascar is the center of chameleon diversity, with over 75 species, many endemic, living there.  Neighboring Africa, despite being vastly larger, boasts only 100 or so species.  Only 2 species make their homes in the Middle East, 2 in Europe and 2 in India and Sri Lanka.

At least 2 species of chameleon have established feral populations in foreign habitats.  The veiled chameleon (Chamaeleo calyptratus) thrives in Florida, Hawaii and Mexico, while the Jackson’s chameleon (C. jacksonii) has been breeding on Hawaii since the 1970’s and has recently been discovered in California.

The Senegal Chameleon, Chamaeleo senegalensis

Hailing from tropical West Africa (Senegal to Cameroon), this dark-spotted, tan to olive chameleon inhabits brushy savannas and forest edges.  Often abundant and easy to collect, it has long been a pet trade staple.

Some Cautions

Despite its long history in captivity, the Senegal does not breed regularly, and presents some problems as a pet.  Wild caught specimens should be avoided, as they are usually heavily parasitized and afflicted with stress related ailments.

Captive Environment

Senegal Chameleons need quite, heavily planted screen cages or an outdoor aviary , abundant UVB radiation and should be kept well-hydrated via frequent spraying or the use of a mister.  An ambient temperature of 76F with a basking site of 85F and a nighttime dip to 69-70F suits them well.

Breeding

If you are lucky enough to obtain a breeding pair, you’ll have your hands full…healthy females may lay 20-70 eggs at a time, twice each year!  Incubation time averages 6 months at 77 F, and sexual maturity may be reached by 5 months of age.

The Smooth Chameleon

The range of East Africa’s Smooth Chameleon overlaps that of the Senegal in Cameroon.  Formerly classified as a subspecies, the smooth chameleon has now been given full species status as Chamaeleo laevigata.

Male Chameleon in Madagascar image referenced from wikipedia and originally posted by Mbz1
Veiled Chameleon in Madagascar image referenced from wikipedia and originally posted by Billybizkit

Hello, Frank Indiviglio here.  Please see Part I of this article  for my “close call” with some cyanide-producing millipedes.  

Millipede Generated Cyanide and Poison Frogs

It seems that millipedes of many types (there are over 10,000 species described to date) mix hydrogen cyanide, quinones, phenols and aldehydes with enzymes to create toxic defensive sprays and secretions.  In fact, tiny millipedes consumed by poison frogs (Dendrobates spp.) account for some if not most of the virulent skin toxins found in the skins of these colorful amphibians. 

Much like the frogs, millipedes seem to obtain at least some defensive chemicals from their diet.  As is true with poison frogs and related species, the toxicity of the millipedes’ secretions decreases over time when they consume captive diets. 

Monkeys and People Draft Millipedes to Battle Pests

The monkeys studied by my friend (please see Part I) were using the millipedes as a mosquito and parasite repellent.  The millipedes seemed quite valuable to the monkeys – so much so that the normally arboreal primates left the safety of the tress to retrieve any millipedes that had been accidentally dropped.

Certain millipede secretions also have antibacterial properties, and are being investigated for medicinal use…it is not known if monkeys exploit this aspect of the toxins as well.

Millipedes as Pets

Millipede secretions can irritate our skin, mucus membranes and eyes, so I always caution people to handle them with gloves and to keep the animals away from one’s face.  Stressed millipedes confined in airtight containers have been known to expire from the concentrated effects of their own toxins.

That being said, millipedes make extremely interesting terrarium subjects, and a number breed well in captivity.  Next time I’ll cover the care of a few regularly available species. 

Further Reading

Millipedes have other defensive tricks as well.  A tiny millipede native to Florida uses detachable bristles to disable ants and other predators.  Read more here.

Until then, please write in with your questions and comments. 

Thanks,

 Frank Indiviglio

Harapahe haydeniana image referenced from wikipedia and originally posted by Folini
Millipede image referenced from wikipedia and originally posted by Esculapio

Please see Part I of this article to learn about the natural history of the Panamanian Golden Frog , Atelopus zeteki, including it’s unique mode of communication.

Status of Wild Populations

Panamanian Golden Frog numbers are plummeting, most likely due to an epidemic of the largely incurable fungal infection

Chitridiomycosis. The fungus responsible, Batrachochytrium dendrobatidis, has been implicated in the declines and extinctions of numerous amphibian species worldwide. This frog is also threatened by deforestation, stream siltation, pollution and collection for use as a promotional tool in Panama’s restaurant, hotel and tourism industries (this practice is illegal, but enforcement is often lax).

It is estimated that Golden Frog populations have declined by 80% in both numbers and extent of occurrence over a 10 year period. At least 2 distinct populations are extinct, with 1 such extinction occurring within the span of several months. Golden Frogs are designated as “Critically Endangered” by the IUCN and listed on Appendix I of CITES. They are legally protected by Panama and the subject of a cooperative rescue program, administered by the USA and the Republic of Panama, known as “Project Golden Frog”. Fortunately, the Golden Frog breeds well in captivity.

Unique Skin Toxins

This frog’s skin contains extremely virulent nerve toxins that differ from those produced by other amphibians. Known as “zetekitoxins”, the poison contained in the skin of a single 2-inch-long frog is sufficient to kill 1,200 mice! It is believed that these toxins are produced in association with symbiotic bacteria, but this has not yet been definitively documented.

Cultural Significance

The Panamanian Golden Frog is the national animal of the Republic of Panama, and has traditionally been associated with matters relating to good fortune. Pre-Columbian indigenous people molded its likeness in gold and clay talismans known as “huaces”.

Further Reading

You can learn more about Project Golden Frog by clicking here.

 

In Part I of this article, we learned that less than 1% of the world’s 40,000+ spider species are dangerously venomous.  Today I’d like to highlight their valuable role as insect predators and point out a few reasonable precautions that should be taken when keeping spiders in captivity.

Hunting Methods and Diet

Spiders consume animals ranging from mites to birds.   Not all ensnare their prey in webs…some hunt by running (wolf spiders), swimming (European diving bell spider), spitting silk (spitting spider), hiding in flowers (crab spider), throwing webs (bolas spider), luring fishes while floating (fishing spiders) or rushing from burrows fitted with hinged doors (trap door spider).

However, all spiders consume insects, including agricultural pests and disease-bearing species, to some degree.  Field research has shown that harmful flies comprising over 60% of the diet of certain web-building species.  It is estimated that the weight of the insects consumed yearly by spiders in New Zealand exceeds that of the island’s human population!

Precautions – Bites and Urticating Hairs

The fact that so few spiders are dangerous to people should not be taken as a license to ignore caution when dealing with them. Just as with bees and other venomous animals, allergic persons can be injured or killed by the bites of relatively benign species, and potentially fatal infections can be associated with the bite of any animal.

Also, many tarantulas shed urticating (irritating) hairs when disturbed or even when just moving about. A colleague of mine underwent major surgery to remove such hairs, deposited on his hand by a “tame” red-kneed tarantula, from his eye.

That being said, I have kept native and exotic spiders since childhood, and have never been bitten – because I do not pick up spiders with my hands.  I urge you to handle spiders, if at all, with plastic tongs or by ushering them into a container.

Further Reading

The diving bell spider is certainly one of the world’s most interesting invertebrates – living within a submerged shelter that exchanges oxygen with the surrounding water and swimming after small fishes!  To read more, click here.

 

Misumena vatia with wasp image referenced from wikipedia and originally posted by Olei.

Please see Part I of this article for a general discussion regarding the collection of insects and other invertebrates and their use in the diets of captive reptiles, amphibians, birds, invertebrates and fishes. Today I’d like to focus on some areas of special concern.

Toxic and Biting/Stinging Invertebrates

While not involving pesticides per se, for your own safety and that of your collection it is imperative that you learn to identify the toxic or otherwise dangerous invertebrates that you may encounter while collecting. A good field guide (i.e. Audubon, Golden Guide or Peterson series) is indispensable in this regard. Be sure to handle unfamiliar species with plastic tongs.

Please bear in mind that even relatively mild bee venom can cause fatalities in allergic people. And while less than 1% of the world’s 40,000+ species of spiders are considered dangerously venomous to us, a number readily bite both people and animals in self defense. It is best, therefore, to avoid them…the Thin-legged Harvestman or “daddy long-legs”, which are not spiders, are safe to use. Steer clear also of bees, wasps, large ants, stag beetles and others well-equipped to defend themselves.

Bright colors often indicate that an animal is toxic or bad-tasting; ladybugs, fireflies, milkweed bugs and a great many others fall into this category. Unless you are sure of an insect’s identity, the safest course of action is to avoid brightly-colored species.

Native vs. Non-Native Prey Species

In many cases, predators avoid dangerous prey animals that occur naturally within their ranges; this can spare both pet and pet-keeper a good deal of grief!  However, dangerous non-native prey animals may be attacked with abandon if the hunter has no “frame of reference”, so use extra caution in such cases.

I have, for example, housed highly-toxic Marine Toads with Green Anacondas for decades without incident, despite the fact that anacondas consume non-toxic frogs readily. However, Australian monitors and snakes, which have no instinctive or learned toad avoidance behavior, eagerly consume the Marine Toads that have been introduced there, often with fatal results.

Earthworms

Earthworms are one of the most nutritious live foods available. There are, however, situations that warrant precautions.

Earthworms are unique in consuming dirt as they tunnel, and in doing so may concentrate toxins present there. To my knowledge, the only problem that has arisen thus far has involved worms that dwell along golf courses, which are subjected to unusually high degrees of pesticide application. Please see my article Raising Earthworms for details concerning striped skunks and earthworms in NY.

West Nile Control and Related Programs

Avoid collecting invertebrates for 1 week after an area has been sprayed as part of West Nile eradication efforts, and steer clear of farms where pesticides are known to be applied regularly. Avoid also local insects that are considered to be agricultural pests, as they are likely the subject of control measures (this may apply to aphids, caterpillars, Japanese Beetles, etc.).

Enjoy

Despite the precautions that must be taken, invertebrate collecting is a fascinating and thoroughly enjoyable endeavor. Don’t forget to examine your catch closely…several years ago a new species of centipede was uncovered in NYC’s Central Park, on ground trod daily by thousands of people. Like me, you just may wind up keeping some of your discoveries in captivity for their own sake!

Further Reading

For a very interesting account of how toads learn to avoid stinging insects, please see my article Amphibian Learning Abilities.

Please write in with your questions and comments.

 

Black Widow image referenced from wikipedia and originally posted by Trachemys.

Milkweed Bugs image referenced from wikipedia and originally posted by Greg5030.