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Contains articles and advice on a wide variety of frog species. Answers and addresses questions on species husbandry, captive status, breeding, news and conservation issues concerning frogs.

Frog Facts: First Discovery of Egg Care by a Southeast Asian Treefrog

C. vittatus

Uploaded to Wikipedia Commons by Andy king50

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.

 

Midwife Toad with eggs

Uploaded to Wikipedia Commons by Fice

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 ).

 

Chinese Flying Frog

Uploaded to Wikipedia Commons by Dger

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).

 

Hi, my name is Frank Indiviglio. I’m a herpetologist, zoologist, and book author, recently retired from a career spent at several zoos, aquariums, and museums, including over 20 years with the Bronx Zoo.

 

Please check out my posts on Twitter and Facebook.   Each day, I highlight breaking research, conservation news and interesting stories concerning just about every type of animal imaginable. I look forward to hearing about your interests and experiences as well, and will use them in articles when possible.

 

Please also post your questions and comments below…I’ll be sure to respond quickly. Thanks, until next time, Frank.

 

Further Reading

Tree Dwelling, Wood-Eating tadpoles Discovered!

 

The Fang-bearing Tadpoles of the Vampire Frog

 

 

Pet Frogs and Toads: Five Points to Consider Before Buying

Budgett's Frog

Uploaded to Wikipedia Commons by Rosarinagazo

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.

 

Pine Barren's Treefrog

Uploaded to Wikipedia Commons by Lonerockalex

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!

 

Blue Poison Frog

Uploaded to Wikipedia Commons by Wildfeuer,

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.

 

Snowy tree cricket

Uploaded to Wikipedia Commons by PaulT

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.

 

Indian Bullfrog

Uploaded to Wikipedia Commons by Amada44

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.

Hi, my name is Frank Indiviglio. I’m a herpetologist, zoologist, and book author, recently retired from a career spent at several zoos, aquariums, and museums, including over 20 years with the Bronx Zoo.

Please check out my posts on Twitter and Facebook.   Each day, I highlight breaking research, conservation news and interesting stories concerning just about every type of animal imaginable. I look forward to hearing about your interests and experiences as well, and will use them in articles when possible.

 

Please also post your questions and comments below…I’ll be sure to respond quickly. Thanks, until next time, Frank.

 

Further Reading

 

Nutritious Diets for Frogs and Toads

Toad Care: Common and Unusual Species

 

 

My Frog’s Color is Fading! Diet Changes can Brighten Frog Colors

Congo Reed Frog

Uploaded to Wikipedia Commons by Nhobgood

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.

Fire bellied toad

Uploaded to Wikipedia Commons by Pkuczynski

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.

Painted Mantella

Uploaded to Wikipedia Commons by Esculapio

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. Hi, my name is Frank Indiviglio. I’m a herpetologist, zoologist, and book author, recently retired from a career spent at several zoos, aquariums, and museums, including over 20 years with the Bronx Zoo. Please check out my posts on Twitter and Facebook.   Each day, I highlight breaking research, conservation news and interesting stories concerning just about every type of animal imaginable. I look forward to hearing about your interests and experiences as well, and will use them in articles when possible.   Please also post your questions and comments below…I’ll be sure to respond quickly. Thanks, until next time, Frank.  

Further Reading

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

Zoo Med Pacman Frog Food for Horned Frogs and African Bullfrogs

t264488Frog owners have recently been presented with an interesting alternative to live insects and rodents as a pet food source. Continuing its trend of pioneering innovative, well-researched products, Zoo Med has introduced a powdered food that can be molded into various sizes and tong-fed to frogs. Although long-term studies on the value of commercial diets are lacking, experience indicates that some prepared/artificial diets have proven very useful. For example, thousands of generations of Mexican Axolotls have been bred (in research labs) on beef liver alone, African Clawed Frogs and many newts do well on Reptomin-based diets, and trout chow seems useful for American Bullfrogs. In both in zoos and my own collection, I have raised Mexican Axolotls and various newts, salamander larvae, and tadpoles primarily on trout chow and Reptomin. Zoo Med’s Pacman Food is eagerly accepted by African Bull and Horned Frogs (no surprises there -please see video below!) and Marine Toads. It’s likely that other “bold” amphibians, such as White’s Treefrogs, Fire Salamanders, American Toads, would be willing give this untraditional food a try as well.

 

Why Consider a Prepared Diet?

Usually, commercial diets are promoted for convenience-sake and as an option for pet owners who do not wish to handle live insects or rodents. However, I’m mainly interested in Zoo Med’s Pacman Frog Food because it may help to solve 2 recurring problems faced by frog owners. The first is the difficulty in providing adequate dietary variety. Wild amphibians utilize dozens to hundreds of species as food, but most pets must make do with 2-3 food items at best. Owners of African Bullfrogs, Horned Frogs, Cane Toads and other giants face the additional task of “filling-up” their pets and providing enough calcium without over-using rodents (while some success has been had on

Argentine Horned Frog

Uploaded to Wikipedia Commons by avmaier

mouse-based diets, there are also risks…please see this article).

 

Providing enough high-quality food can be a major undertaking – please see the article linked below to read about an African Bullfrog caught in the act of swallowing 17 baby cobras! Zoo Med’s product, which one mixes with a bit of water, can be molded into any size (or shape!), and so might be useful to people keeping dinner-plate sized amphibian behemoths.

 

Some Considerations

We do not have studies illustrating benefits or problems associated with this food; long-term success is claimed by a Japanese company manufacturing a related product. The examples I mentioned earlier (amphibians fed dry foods, liver, etc.) may be somewhat relevant, but we cannot draw any direct conclusions about Horned Frogs or others from these.

 

Surinam Horned Frog

Uploaded to Wikipedia Commons by Maarten Sepp

I would suggest trying Zoo Med Pacman food as a portion of your pets’ diets. Continue to provide as much variety as possible, and choose from nutritious foods such as roaches, earthworms, sowbugs, minnows, crickets and silkworms. Please see the article linked below for other ideas, including the use of wild-caught insects.

 

In posts on other sites, some folks have expressed concern over the plant-based ingredients in this product, or the fact that fish is used as a protein source. While on-point research is lacking, it is well-known that frogs and other carnivorous animals take in a good deal of plant matter in the course of feeding upon herbivorous prey species. Fish, which I and others have long fed to many large frogs, does not seem to present any problems. Zoo Med Pacman Food also contains added vitamins and minerals, including calcium and Vitamin D.

 

Those who have tried will not need this warning (I’m sure!), but I should remind you not to feed Horned or African Bullfrogs with your fingers. The bony, tooth-like spikes that protrude from their jaws can inflict severe injuries. As most frogs seem to lack “self-control” when it comes to lunging at prey, use plastic feeding tongs only…sharp-edged metal models may injure your pets’ mouths.

 

Hi, my name is Frank Indiviglio. I’m a herpetologist, zoologist, and book author, recently retired from a career spent at several zoos, aquariums, and museums, including over 20 years with the Bronx Zoo.

Please check out my posts on Twitter and Facebook.   Each day, I highlight breaking research, conservation news and interesting stories concerning just about every type of animal imaginable. I look forward to hearing about your interests and experiences as well, and will use them in articles when possible.

 

Please also post your questions and comments below…I’ll be sure to respond quickly. Thanks, until next time, Frank.

 

Further Reading

Video: Using Pacman Food

African Bullfrog Consumes 17 Baby Cobras

Nutritious Live Foods for Frogs

 

The Most Astonishing and Bizarre Newly-Discovered Frogs

 

Mimic Poison Frog

Uploaded to Wikipedia Commons by Gabsch

Be it the discovery of a new species in the middle of NYC or the revelation that Mimic Poison Frogs are monogamous, frog enthusiasts are accustomed to surprises.  But those revealed in the last few years have been especially interesting and unexpected…frogs with sheathed claws, tadpoles that feed upon their father’s skin and on tree bark, bird-eating, bird-voiced and lungless frogs, fanged tadpoles and much, much more.  Were I new to this field, I’d consider much of the following article as pure fantasy…but even after a lifetime of working with amphibians, I’m still shaking my head.

 

Note: please see the linked articles for further information on the frogs introduced here.

 

 

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