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

As the summer weather cools and kids return home from camp, questions concerning Red Eft care are among the most frequent I receive. Bold, brightly-colored, and often out by day, Red Efts are more commonly-collected by children than any other amphibian. And, being attractive and seemingly-benign, they are also less likely to be rejected outright by parents. However, efts are temperature sensitive and require a specialized diet. Unfortunately, they are poorly-suited to captivity, especially when inexperienced owners are involved. In the following article I’ll explain why, and will offer some alternative species and care tips to folks intent on trying to keep these beautiful salamanders.

 

Natural History: What is an Eft?

The term “Eft” refers to a temporary land stage in the life cycle of the Eastern Newt (Notophthalmus viridescens). This species’ huge range extends from southern Canada through most of the central and eastern USA to Texas and Florida; in North America, only the Tiger Salamander has a wider distribution. Four subspecies have been described.

 

The olive-green, red-spotted adult newts are aquatic, and at one time were a pet trade mainstay. Many states now prohibit collection, but where ownership is legal they make wonderful introductions to amphibian care (please see the article below).

 

In most populations, Eastern Newt larvae transform into orange to red-colored efts. The efts leave the natal pond and take-up residence in forested areas. The eft stage generally lasts from 2-3 years, but may extend to 7 years in the northern part of the range and in mountainous habitats. The eft stage is skipped in certain populations, with the larvae developing directly into aquatic adults. “Eft-skipping” was first documented on Long Island, NY, but has since been found among all subspecies, and across the range. It most often occurs where the land surrounding breeding ponds is sandy or otherwise inhospitable to moisture-loving amphibians.

 

Skin Toxins

Efts are well-protected by powerful skin toxins. This seems to account for their tendency to wander about on damp days, seemingly oblivious to the attentions of curious children (always wash after handling one, as their skin secretions can irritate mucus membranes, eyes and wounds). Several other species, including the Mud Salamander (Pseudotriton montanus) and the Red Salamander (P. ruber), are believed to mimic the Red Eft in order to discourage predators.

 

Captive Diet

Wild-caught efts are not at all shy, and willingly forge by day. Judging by the questions I receive, however, it seems that many Red Eft owners are first-time salamander keepers, and are not prepared for the work involved in keeping these gaudy little gems. By the time most folks write in, their once-perky little pets are lethargic and emaciated.

 

Red Efts require a highly-varied diet comprised of tiny invertebrates, and will not accept the dry foods and pellets favored by adult newts. Those experienced in keeping Dart Poison Frogs and other small amphibians usually have no trouble with efts, as a number of frog foods suit them well. Flightless fruit flies, 10-day old crickets, springtails, bean beetle larvae and sow bugs can be purchased from online dealers, and are readily accepted. In order to add variety to the diet, termites, millipedes, tiny earthworms, beetles and other small leaf-litter invertebrates should also be collected when possible (please see the article linked below).

 

Heat Sensitivity

While different eft population vary in regard to temperature requirements, most fare poorly when kept at 72 F or warmer for any length of time. A cool basement or similar location is essential to their survival.

 

Look But Don’t Touch

Children are drawn to efts because they accept handling without protest. However, it’s important to realize that handling damages the skin’s protective mucus covering, leaving the animal exposed to attack by bacteria and other pathogens. As mentioned above, skin secretions can also irritate people. Furthermore, all amphibians can be assumed to harbor Salmonella bacteria. While infections are easily preventable if proper hygiene is maintained, children must be supervised carefully.

 

Eft Alternatives

 

Those seeking a land-dweller cannot do better than the Fire Salamander. These gorgeous creatures, captive bred in large numbers, are among the most responsive of all amphibians…and, with proper care, they may live to age 30, 40, or beyond! Please see the article linked below.

 

A wide array of semi-aquatic species, including Fire-Bellied, Paddle-Tailed and Ribbed Newts, are being bred in captivity and make hardy, long-lived pets. As mentioned earlier, the Red Eft’s adult phase is also a good choice, but captive-bred specimens are scarce. Please see the linked articles and post your comments below if you’d like more details on newt and salamander care.

 

 

Further Reading

Eastern Newt Care

 

Collecting Leaf Litter Invertebrates

 

Fire Salamander Care

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)

 

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

 

 

We amphibian enthusiasts are a lucky bunch. The world is populated by 6,389 frog and toad species, and new ones are discovered regularly. Among them we find frogs that have sheathed claws, lack lungs and defend their young from lions, along with toads that breed in salt marshes and bear live young. Some tadpoles feed upon their fathers’ skins, while others munch bark from tree branches…and that’s the mere tip of the iceberg! Frogs may be hardy survivors that can reach age 20, 30 or even 50, or be nearly impossible to keep alive in captivity. The following points, drawn from a lifetime of working with frogs and toads in the Bronx Zoo and at home, are useful to consider before embarking on your amphibian-keeping venture.

 

Note: The terms “frog” and “toad” do not always correspond with taxonomic relationships. All toads may be correctly called “frogs”. I’ll use “frogs” when referring to both.

 

Please post below if you have specific questions, or would like a link to an article on a certain species.

 

Pet Frogs are “Hands-Off”

Cane Toads, White’s Treefrogs and many others are often very responsive to their owners, and will readily feed from the hand (or, for the “tooth” bearing African Bullfrog and Horned Frogs, from tongs!). However, they should be picked-up only when necessary, and then with wet hands. All amphibians have extremely delicate skin, and even microscopic tears will allow harmful bacteria to enter and cause havoc. Also, the skin’s mucus covering, which has anti-microbial properties, is easily removed even during gentle handling.

 

Well-cared-for frogs will reward you by exhibiting fascinating behaviors…but not if you disturb or injure them with unnecessary handling!

 

Frogs Need Clean Terrariums and Excellent Water Quality

An African Bullfrog can eat baby cobras, survive 9 months without food and live for over 50 years. Yet 2-3 days of soaking in a fouled water bowl can end its live.

 

Frogs absorb water through the skin, and along with that water comes any associated pollutants. The most common of these is ammonia, which is excreted with the waste products. Most frogs are as or even more delicate than tropical fishes, since they absorb water over a greater surface area; ammonia test kits, partial water changes and strong filtration are critical to success in keeping them. Substrate needs the same attention as does water, since Horned Frogs and other land-dwellers can be poisoned by ammonia-soaked moss or soil.

 

Frogs Need a Highly-Varied Diet

No frog will thrive long-term on a diet comprised solely of crickets and mealworms, even if these foods are powdered with supplements. I’ve done well by relying heavily upon wild-caught invertebrates during the warmer months.  Moths, beetles, grasshoppers, tree crickets, harvestmen, earwigs, “smooth” caterpillars and a variety of others are accepted – usually far more enthusiastically than are crickets!. Please see these articles for tips on collecting insects.

 

Useful invertebrates that you can buy include earthworms, roaches, butterworms, calciworms, silkworms, hornworms and sow bugs.  Feeders should be provided a healthful diet before use.  Canned grasshoppers, snails, and silkworms may be offered via feeding tongs. Please see the article linked below for further information on dietary variety.

 

Frogs are Easily Stressed…but it’s Hard to Tell

Stress is one of the most important and misunderstood concepts in herp husbandry. While some frogs will leap away when threatened, many instinctively freeze. Inexperienced owners often misinterpret the lack of vigorous protest as an “acceptance” of handling. However, be assured that your pet’s stress hormones are surging, and that this will have a deleterious effect on its immune system.

 

Being relatively inactive, many frogs may seem blissfully unaware of terrarium size, or of what is going on outside their enclosures. However, most are quite alert, and miss nothing. It may be difficult for us to detect a problem merely by observing our pets’ behaviors.

 

Certain species, such as White’s Treefrogs, American or Southern Toads, and African Clawed Frogs, are better-suited to busy households than are most.

 

The “It Doesn’t Do Anything” Factor

Ideally, the new frog owner will be interested in her or his pet for its own sake. But most of us also wish to see how it lives, what it does, and so on. Many frogs are about as active as the infamous “pet rock”…and are nocturnal to boot!

 

If you favor an active pet, consider a small diurnal species that forages for rather than ambushes its food, and keep it in a large, naturalistic terrarium. Five Blue Dart Poison Frogs (active hunters) in a well-planted 30 gallon tank will provide you with infinitely more to observe than will an Argentine Horned Frog (ambush predator) kept in the same-sized enclosure. African Clawed and Dwarf African Clawed Frogs also tend to be quite active, especially if housed in planted aquariums and not over-fed. Allowing sow bugs, springtails and other food species to become established in the terrarium will encourage activity.

 

Some species that tend to be active at night may adjust to daytime schedules once they settle into to their new homes. American Toads and their relatives are especially accommodating in this regards. Others, such as Green and Gold Bell Frogs, American Bullfrogs and Leopard Frogs, are ready and willing to feed round-the-clock. Red night-viewing bulbs will greatly increase your ability to observe Red-Eyed Treefrogs, Spadefoot Toads and other strictly nocturnal species.

 

 

Further Reading

 

Nutritious Diets for Frogs and Toads

Toad Care: Common and Unusual Species

 

 

Frogs that are clad in yellow, orange, and red, such as Fire-Bellied Toads and Red-Eyed Treefrogs, often become somewhat dull in coloration after a time in captivity. I’ve noticed this in a variety of species under my care in zoos and at home, yet the phenomenon is rare in the wild or among animals kept outdoors under semi-natural conditions. Color loss can also indicate a health concern (please see below), but often the affected animals are robust and doing well. A photograph showing an astonishing difference in coloration between Red-Eyed Treefrogs maintained on 2 different diets recently caught my eye, and I thought it might be useful to summarize the related research here.

Acquiring Color: Why are Red Frogs Red?

Pigments known as carotenoids are responsible for most of the orange, red and yellow coloration exhibited by frogs. Color is important not just from an aesthetic point of view (or a monetary one, for those who breed “designer frogs”!) but may also affect breeding success and the ability to hide from or deter predators.

In addition to these roles, carotenoids also act as antioxidants and function in the immune and other systems. Carotenoids are manufactured by plants, bacteria and fungi; frogs and other vertebrates must obtain them from their diet.

Improving the Carotenoid Content of Feeder Insects

Researchers at the University of Manchester and the Chester Zoo investigated carotenoid levels in three species of crickets and three different cricket diets (Zooquaria, No. 5, p.6). One of those studied, the Domestic or House Cricket, Acheta domesticus, is used for pet food in the USA. The others – the Tropical House Cricket, Gryllodes sigillatus, and the Mediterranean Field Cricket, Gryllus bimaculatus – are more commonly seen in European and Asian collections.   A diet comprised of fruits and vegetables provided crickets with the highest carotenoid levels. A tropical fish food (flakes) diet resulted in intermediate carotenoid levels, and the lowest levels were seen in crickets feeding upon wheat germ and other grains.   Mediterranean Field Crickets achieved higher concentrations than did the other species, but none retained carotenoids for very long. Carotenoid levels plummeted within 48 hours, so gut-loaded crickets should be used within a day or so after consuming fruits, vegetables and other carotenoid rich foods; please see the article linked below for further information.

Future Research

Although the study was spurred by an interest in the effect of carotenoids on the immune system, the coloration aspect is starting to attract attention (please see photos of red-eyed treefrogs here). Further study is needed, but it’s clear that adding fruits and vegetables to the diets we provide crickets, roaches and other feeders makes good sense. Bear in mind also that this study looked at one aspect of diet…fresh produce no doubt offers a wide variety of other health benefits.   As a novice bird keeper long ago, I learned that flamingos denied sufficient shrimp and canthaxanthin soon “bleach-out”…today we still know far more about this topic as it relates to birds than to amphibians. But some of that knowledge may have applicability to herps – in any event, I hope that more private keepers and researchers will take an interest. I’ll stay alert for updates; in the meantime, please post any relevant thoughts and links below, thanks.

Further Reading

Nutritious Foods for Frogs and Toads Cricket Nutrient Level Study Cricket Care and Feeding