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

An Australian frog that copes with droughts by entering a hibernation-like state known as aestivation is now the focus of important bio-medical research. Despite being immobile for months at a time, the Striped Burrowing Frog (Cyclorana alboguttata) suffers little of the muscle loss seen in immobile people, and in astronauts who spend long periods at reduced gravity. Two related frog species that I was lucky enough to acquire many years ago were also able to weather months without water, and in many ways seemed to be the ecological equivalent of another favorite of mine, the African Bullfrog.

 

The “African Bullfrogs of Australia”

The 13 squat, large-mouthed frogs in the genus Cyclorana are restricted to Australia, where many inhabit drought-prone regions that are inhospitable to other amphibians. Although classified with treefrogs in the family Hylidae, these odd beasts are about as far-removed from typical treefrogs as can be imagined – in fact, likely never see trees, considering where they live!

 

The two species that I’ve kept, the Water Holding Frog (C. platycephala) and the New Holland Frog (C. novaehollandiae), looked and acted like mini-African Bullfrogs. Capable of taking enormous meals (including same-sized tank-mates), they grew almost before my eyes. In the wild, most breed in temporary pools whenever it rains, eat like mad, store water in the bladder, and then disappear below ground. If the dry period is prolonged, a cocoon of shed skin will be formed about the body.

 

Muscle-Protecting Genes Discovered

The Striped Burrowing Frog has often been used as a model in studies seeking to slow or reverse muscle wasting in immobile people. Related studies have revealed that the loss of muscle tissue that occurs when we are unable to move is caused by protein-degrading molecules known as Reactive Oxygen Species.

 

Now, researchers at the University of Queensland have isolated a specific gene that seems to protect this frog’s muscle cells from damage during long periods of inactivity. As the gene, aptly named Survivin, is also found in humans, lessons learned by studying the frog could possibly be of benefit to us as well.

 

Another gene that may help to avoid muscle loss has also been identified. Known as Checkpoint Kinase 1, this gene regulates cell division and DNA repair. Researchers are also investigating the possibility that Striped Burrowing Frog muscles are assisted by high levels of protective antioxidants.

 

Applying these findings to human patients seems to be a long way off, but the research hold promise. In fact, similar muscle-protecting mechanisms have been found to be at work in hibernating mammals such as squirrels, which are a bit closer to us on the evolutionary scale.

 

I’ll pass along updates as they become available…please also share anything related that you may learn by posting below, thanks.

 

 

Further Reading

 

The Most Bizarre New Frogs

 

Amphibian learning Abilities (Toad Meets Bee)

 

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

The breeding habits of a poorly-studied treefrog have recently grabbed the attention of herpetologists and amphibian enthusiasts. Although it is small in size and lacks a common name, Chiromantis hansenae is quite special. Recent research has revealed it to be the only Southeast Asian treefrog known to provide parental care to its eggs. Furthermore, it breaks the typical rules that apply to most other egg-guarding frogs in important ways. Very little is known about Chiromantis hansenae, which until now was thought to be an “un-remarkable” little frog – a clear sign that important discoveries await those willing to search.

 

Eggs Die Without Mom’s Care

Chiromantis hansenae’s unexpected egg-brooding behavior was first observed by researchers from the National University of Singapore. Writing in the journal Ethology (V. 119, N. 8, p 671-679), they describe how females deposit egg masses in trees and then cover the eggs with their bodies. Egg-attending treefrogs sometimes descend to the ground and soak for a time in nearby ponds, after which they return and re-position themselves above the eggs. This behavior apparently supplies the eggs with water and also limits the amount of water lost via evaporation…most of the egg masses from which females were removed (by researchers) dried up and failed to hatch.

 

Chiromantis hansenae differs from most other egg-brooding frogs in several important ways. In other species, few large eggs are produced, and the male provides most or all of the parental care (please see photo of male Midwife Toad carrying eggs).  Such eggs are generally deposited on land, and direct development (from egg to small frog) is typical. Chiromantis hansenae, by contrast, produces many tiny eggs and deposits them above-ground, and tadpoles rather than small frogs emerge from the eggs.

 

Conservation Implications

Why has this unique breeding strategy evolved, and how many other species rely upon it? Answering such questions is crucial if we are to understand and conserve the world’s frogs, many of which are facing an extinction crisis.

 

That such a small, unassuming frog could hold these secrets should inspire us to look at all creatures with deep respect and interest. One never knows where the next unforeseen discovery will arise, or how important it will be from a conservation perspective. Despite Southeast Asia’s incredible diversity of amphibians, the study mentioned above is the first to closely examine parental care in any of the region’s frogs.

 

Unfortunately, little is known of Chiromantis hansenae’s natural history; the range, usually given as Thailand and Cambodia, is poorly-defined. The IUCN lists this frog as “data deficient”, and some herpetologists doubt that it is a distinct species, classifying it instead as the widely-ranging C. vittatus (note: the first photo, above, is of C. vittatus; you can see a video clip of C. hansenae here ).

 

Related Frogs

Chiromantis hansenae is classified in the family Rhacophoridae, along with several treefrogs that are popularly-kept in captivity by amphibian enthusiasts. Included among them are two of my personal favorites, the Chinese Flying Frog (Rhacophorus dennysi, please see photo) and the African Gray Foam Nest Frog (Chiromantis xerampelina).

 

 

 

Further Reading

Tree Dwelling, Wood-Eating tadpoles Discovered!

 

The Fang-bearing Tadpoles of the Vampire Frog

 

 

The well-named Ornate Wood Turtle (Rhinoclemmys pulcherrima), also known as the Painted Wood Turtle, Honduran Wood Turtle or Central American Wood Turtle, is one of the most exquisitely-beautiful land turtles in the Western Hemisphere. The first I saw, as a boy working for a NYC animal importer, stopped me in my tracks…as did others encountered in the field 30 years later! As curious and intelligent as the North American Wood Turtle (they are not related, by are similar in many ways), these striking creatures make wonderful, long-lived pets, and are regularly bred in captivity.

 

Description

Ornate Wood Turtles vary greatly in coloration, with some specimens being hard to describe in words. Those sporting the most color tend to be found in the southern portion of the range, and are classified as the subspecies R. p. pulcherrima. However, all are gorgeous, and unusually-brilliant examples may be found among any of the 4 subspecies, and in captive-produced hybrids.

 

The carapace is deeply etched by the growth annuli, resulting in the same rough, sculpted look that we see in the North American Wood Turtle. The shell is clad in subdued-to-vivid red and yellow blotches and eye-spots, and a complex pattern of red and orange lines marks the head. Adults average 7-8 inches in length, with males being the slightly-smaller sex.

 

Range and Habitat

The four Ornate Wood Turtle subspecies range from Sonora, Mexico along the western half of the country to Costa Rica; they also occur in eastern Guatemala and eastern Honduras.

 

Largely terrestrial but often entering shallow water, they favor forest edges and riverside thickets and sometimes adapt to overgrown fields and farm borders.

 

The Terrarium or Cage

Ornate Wood Turtles reach 8 inches in length and are quite active. A spacious home is essential to their health and well-being.

 

Hatchlings may be raised in aquariums, but adults do best in custom-made enclosures that measure at least 4’ x 4’ in area; outdoor maintenance is ideal when weather permits. Plastic-based rabbit cages and cattle troughs can also be modified as turtle homes. A pool of shallow water measuring 1’ x 2’ or larger should be available.

 

Suitable hiding spots are important to even well-adjusted pet turtles; these include deep substrates into which your turtles can burrow and commercial shelters such as the Zoo Med Turtle Hut.

 

Substrate

Cypress bark and similar products, or a mix of topsoil, peat and sphagnum moss, may be used as a substrate. I always add dead leaves as well…Ornate Wood Turtles will occupy themselves with hunting for hidden invertebrates each time a new batch of leaves or grass clippings is introduced.

 

Light

Ornate Wood Turtles need daily exposure to UVB light. Natural sunlight is ideal, but be aware that UVB rays do not penetrate glass or plastic, and that fatal overheating can occur quickly.

 

Your turtle should be able to bask within 6-12 inches of a high-output UVB florescent bulb, such as the Zoo Med 10.0. Mercury vapor bulbs broadcast UVB over greater distances, and also emit beneficial UVA radiation. Be sure to provide shaded areas as well.

 

Heat

Temperatures should range from 72-85 F, with a basking site of 90-92 F. Incandescent bulbs may be used by day; ceramic heaters or red/black reptile “night bulbs” are great night-time heat sources.

 

Provide your pet 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 glass aquariums and other small or poorly ventilated enclosures, the entire area soon takes on the basking site temperature.

 

Humidity

Overly dry conditions may cause health concerns. The substrate should be misted daily; moist retreats, a large water area, and a dry basking site must also be available. Reptile humidifiers can be useful in arid climates.

 

Companions

Females and youngsters usually co-exist, but must be watched as dominant individuals may attack others or prevent them from feeding. Males usually fight, and often harass females with near-constant mating attempts.

 

Breeding

Three to five eggs are produced at a time, and females may deposit up to 4 clutches per year. Breeding usually occurs between August and December.

 

Females sometimes have difficulty passing their eggs, especially if the diet lacks sufficient calcium. Gravid (egg-bearing) females usually become restless and may refuse food. They should be removed to a container measuring at least 5x the length and width of the turtle and provisioned with 6-8 inches of slightly moist soil and sand. Gravid females that do not nest should be seen by a veterinarian as egg retention always leads to a fatal infection (egg peritonitis).

 

Feeding

Ornate Wood Turtles have not been well-studied in the wild, but their appetites appear to know no bounds. Pets should be offered a diet comprised of whole animals such as earthworms, snails, crickets and other insects, crayfish, prawn, minnows, an occasional pre-killed pink mouse and a variety of fruits, greens and vegetables. Canned invertebrates, especially snails, can be used to increase dietary variety. A high quality commercial turtle chow such as moistened Zoo Med Aquatic Turtle Food should be mixed into your turtle’s salad.

 

Goldfish should be offered sparingly, if at all, as a steady goldfish diet has been linked to kidney and liver disorders in other turtles. Spinach and various cabbages cause nutritional disorders and should be avoided.

 

The calcium requirements of Ornate Wood Turtles, especially growing youngsters and gravid females, are quite high. All food (other than vertebrates and commercial chow) should be powdered with Zoo Med ReptiCalcium with D3 or a similar product (D3 is not necessary for turtles that have access to natural sunlight). A cuttlebone may also be left in the cage, although not all turtles sample one. Vitamin/mineral supplements such as ReptiVite with D3 may be used 2-3 times weekly.

 

Temperament

Ornate Wood Turtles adjust to captivity quickly, and soon learn to anticipate feeding times and to take food from the hand. Many owners compare them to North American Wood Turtles in responsiveness, intelligence and longevity.

 

 

Further Reading

 

Keeping the North American Wood Turtle

 

Keeled Box Turtle Care