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

Click: My Animal Collection: How a Herpetologist Keeps American Toads, Bufo (Anaxyrus) americanus and Related Species, Part I, to read the first part of this article.

Temperature

American toads are, in contrast to many amphibians, quite resilient in terms of temperature tolerance.   However, they do best at moderate temperatures, and in the heat of summer will attempt to burrow below the substrate.  Mine are kept at room temperature, which ranges from 62 F in winter to 78 F in the summer.  During particularly hot spells, I move them to an air conditioned room or the cool basement.

Naturalistic and “Hybrid” Terrariums

Toads also adapt well to planted, naturalistic terrariums.  A substrate of top soil and peat moss will allow them to construct burrows, which will be used repeatedly by the same animals.  Cover the soil with one of the moss-based products listed above and dead leaves in order to retain moisture.

A “hybrid” type set-up combines certain features of both styles described above.  A substrate of smooth aquarium stones (1/2 inch size or larger, to prevent ingestion) allows for live plants but deters burrowing (see photo).

R-Zilla Rock Dens serve well as shelters in such terrariums, or you can create your own using cork bark or rocks.  When designing rock caves, consider that the toads may injure themselves if able to burrow and collapse the structure.  Exo-Terra Terrarium Plants are extremely life-like and can be used to good effect in naturalistic terrariums as well.

A Terrarium for Public Display

I designed the gravel-base terrarium shown in the accompanying photo for a museum in New York City.  Zoo-Med Terrarium Moss is mixed into the gravel, which itself sits on an Under-gravel Filter Plate.  A drain cut into the tank’s glass bottom allows the entire terrarium to be hosed down.  A water reserve is kept below the under-gravel plate, creating a damp but not wet environment for the resident toads and salamanders.

Feeding American Toads and Their Relatives

Wild Caught Invertebrates

From spring through fall, I feed my toads exclusively upon wild-caught invertebrates.  A Zoo Med Bug Napper yields plenty of moths and beetles, and easily meets their needs.  However, I enjoy poking around, and so also collect tree crickets, sow bugs, harvestman (“daddy longlegs”), millipedes, termites, earthworms, field crickets and caterpillars whenever I am able.  I feed the toads just about every day during the summer (2-3 small insects each) and 2-3 times weekly when temperatures drop.

I avoid spiders, fireflies, ladybugs and brightly-colored insects, due to possible toxicity problems, and do not collect for a week or so after the area has been sprayed to control West Nile virus.

Commercially Available Insects

During the winter, I keep breeding colonies of sowbugs, earthworms and mealworms as a food source for my collection (regarding mealworms, feed toads only newly molted, or white grubs, and beetles).  The balance of the diet is made up of crickets, roaches, waxworms and butter worms.

Training your pet to tong-feed will go a long way in helping you to introduce dietary variety.  By doing so, I have been able to add Zoo Med Canned Caterpillars and Grasshoppers to my toads’ diets.

I powder feeder insects with a Tetra Repto Cal Supplement once weekly during the winter.  I’ve found that such is unnecessary in summer, when wild caught invertebrates dominate the diet.

Some Thoughts on Prey Size

I have always believed that American toads are designed, by mouth structure and feeing behavior, to take smaller-sized prey than do similarly-sized frogs (i.e. the green frog, Lithobates clamitans).  Even when feeding adult toads, I rarely use insects larger than a ½ to ¾ grown cricket.  Toads under my care are still thriving in their late 20’s and, while I cannot document such, I believe that prey size may be a contributing factor.

 

I’ve written other articles on toads and on amphibian care in general.  Please check out the following when you have a chance:

Canned Insects and other Invertebrates – An Important New Food for Pet Reptiles and Amphibians

Making the Most of the Mealworm: some tips on enhancing the nutritional value of this pet trade staple

Providing a Balanced Diet to Reptile and Amphibian Pets – approaches to consider

Terrestrial Isopods (Sowbugs, Pillbugs, Potato Bugs) As Food for Captive Reptiles and Amphibians

The Marine Toad, Bufo marinus (recently re-classified as Rhinella marina) in Nature and Captivity – Part I, Natural History

Today’s article is the second in a series concerning animals in my own collection.  For additional information concerning this line of articles, please see My Animal Collection: How a Herpetologist Keeps Barking Treefrogs (Hyla gratiosa) and Gray Treefrogs (Hyla versicolor).

Note: the following information is also largely applicable to other toads that commonly appear in the pet trade, i.e. the Great Plains toad, B. cognatus, the Gulf Coast toad, B. valliceps, the southern toad, B. terrestris, Woodhouse’s toad, B. woodhousei and the Texas toad, B. speciosus.  Fowler’s toads and the various Spadefoot toads prefer arid substrates…I’ll cover the care of both in the future.

Most North American toads in the Genus Bufo have been recently reclassified within the Genus Anaxyrus, but not all herpetologists agree on this point.

An Ideal Terrarium Pet

As with many of the animals I favor, American toads have much to offer the hobbyist but are not as popular as some of their more colorful relatives (actually, they vary greatly in color – I have run across yellow, reddish and nearly black specimens in the field).

Perhaps because they are so well- protected by virulent skin toxins, American toads are calm and confiding in captivity.  They usually take on diurnal habits, and even wild caught adults will feed from the hand in short order.  Pardon the stretch, but their behavior brings to mind that of the striped skunks I have kept.  Skunks seem to know that they are “untouchable”, and hence are very approachable (even in the wild)…toads are much like that, at least in my mind!

They are also quite intelligent and responsive – please see my article entitled “Amphibian Learning Abilities – the Southern Toad, Bufo (Anaxyrus) terrestris and Bumblebee Mimics” for further details.

Designing the Terrarium

I currently keep 2 yearling American toads in a Tom Aquarium Jumbo PLA-House Plastic Terrarium.  This terrarium’s ventilation ports assure adequate air exchange (despite favoring moist habitats, toads and other amphibians fare poorly in stagnant air) yet are small enough to prevent small feeder insects from escaping.  This set-up is dismantled and cleaned weekly – the terrarium’s light weight simplifies this chore.

Substrate

The substrate pictured in the photo is R-Zilla Compressed Frog Moss.  American toads prefer a drier environment than do most frogs, so I use only ½ to ¾ of the amount of water called for in the instructions when preparing the moss (the moss is packaged dry, and must be reconstituted).  Hagen Exo-Terra Plume Moss and Zoo Med Terrarium Moss are also good choices for toads and other amphibians.

In this terrarium, the substrate is rinsed or spot-cleaned once mid-week and replaced weekly.  As with most amphibian terrariums, I use only hot water to clean, with bleach or table salt added when something stronger is called for.

Water

The terrarium is sprayed once daily with de-chlorinated water.The toads also frequently soak in their water bowl…just bear in mind that they are poor swimmers, so provide an easily-exited container for their pool.

Terrarium Decorations

I set up the terrarium in manner that encourages easy visibility and feeding- time interactions.  This is not always possible with amphibian pets, of course, as secretive species will languish and die if unable to hide.  American toads take to it readily however, and so observations, feeding and cleaning are much simplified.  In this terrarium the toads have become quite tame – noticing when I enter the room hopping forward in anticipation of a meal.

I provide a Zoo Med Turtle Hut or a Cork Bark Hollow as a retreat, but the toads are more often to be found on top of it, scanning the moss for insects or, it seems, watching the room in general.

Light

The PLA-House Hood Light fits right onto the terrarium’s lid, and is useful for providing additional illumination without excess heat.

In planted terrariums, a Reptisun 2.0 Florescent Bulb will provide sufficient light for plants without exposing the toads to harmful levels of UVB – most amphibians have UVB “filters” in their skin, and actively avoid the sun.

Click: My Animal Collection: How a Herpetologist Keeps American Toads, Bufo (Anaxyrus) americanus and Related Species, Part II to read the rest of this article.

 

The bizarre Surinam toad needs little introduction to amphibian enthusiasts…their unique strategy of brooding the eggs below the skin of the female’s back has rendered the species quite well-known. Yet, when I received a group of adults in 1986, I found that little had been published on their husbandry, and the last recorded captive breeding seemed to have occurred in the 1950’s.

Courtship and Fertilization of the Eggs
One female was in breeding condition, as evidenced by the circular, swollen ring about her cloaca and the dark brood patch on her back. Several males were giving forth their metallic, clicking breeding calls, so I chose the most robust of the group and placed him with the female.

Surinam toads swim in a series of circular loops, from the bottom to the top of the aquarium, when in amplexus, and will rarely be successful in fertilizing the eggs unless provided with a tank of at least 48 inches in depth. As the pair reaches the top of their loop, the female lays an egg, which is (on the next loop) fertilized and manipulated by the male onto her back’s spongy brood patch.

My Observations of Amplexus and Birth
Amplexus in the frogs I observed lasted for nearly 3 days, which I have subsequently found is the norm. The pair “shivered” in unison on many occasions, but I was not able to see the “bobbing” motions described by others. The photo accompanying this article shows what might be the first captive breeding (this while I was working at the Bronx Zoo) in many years. Within 24 hours of this photo, the skin on the female’s back swelled and completely covered the eggs.

After egg-laying, I removed the male. The female fed as usual. I did not offer blackworms, as these voracious little beasts burrowed into the soft skin of her brood patch at one point…talk about a horrid sight (I was able to wash them away easily)!

The young began to pop their heads out (the sight of 74 pointed little heads protruding from their mother’s back was yet another vision not for the squeamish!) in 100 days, and swam off on their own within a day or so. They averaged ½ to ¾ inches long, and fed readily upon chopped blackworms, brine shrimp and guppy fry. Sexual maturity was reached in 3 years.

Amazing Healing Abilities
The females back appeared “healed” within 24 hours of giving birth, but remained roughened in appearance for several weeks. Amphibians are increasingly being found to produce compounds of great medicinal value…I wouldn’t be surprised if the incredible skin trauma undergone by female Surinam toads is somehow tempered by a chemical that could be of use to people.

A wonderful video of baby Surinam toads emerging from their mother’s back is posted below:

Baby Surinam Toads emerging from their mother’s back

Harvard biologist David Blachurn knew he was onto something unusual when a benign-looking frog he was examining in Cameroon, West Africa kicked out and left him with a bleeding cut.  Unusual indeed – an article  (23 August 2008) in Biology Letters describes the hidden claws of Perret’s night frog as the only vertebrate claws known to break through the skin in order to become functional.  Some, or possibly all, of the other 10 frogs within the genus Astylosternus are also equipped with skin-covered claws on their toes (the fingers are clawless).

The frog’s sharp, curved claw is actually the last bone of the toe, and pierces the toe’s skin when a specific tendon is flexed.  It is assumed that the claw retracts after use and the skin heals, but further study is needed.  Other amphibians that experience “self-inflicted” wounds include the Surinam toads, Pipa spp., whose young push through the skin of the female’s back when ready to swim off on their own and the ribbed newt, Pleurodeles waltl.  The ribs of this newt pierce the skin of the back, carrying toxins with them, when the animal is threatened.

Despite the massive trauma caused by the emergence of 80+ fully formed little frogs, the skin of breeding Surinam toads (P. pipa) under my care appeared well-healed within 24 hours.  I’m sure there are some compounds that may be of medical use to people hidden in the body chemistry of this and other amphibian species.

Of course, people living within the habitat of Perret’s night frog have long known of its odd defense and even utilize specially-constructed spears when hunting it, to avoid being injured.

The only other frogs known to have claws are members of the family Pipidae – the various African clawed and dwarf African clawed frogs.  I have observed both putting their claws, which are always exposed, to interesting uses (more to come in future articles).

You can read more about this frog and related species at:
http://research.amnh.org/herpetology/amphibia/references.php?id=1191

Click: The Marine or Cane Toad, Bufo marinus (Rhinella marina) in Nature and Captivity – Marine Toads as Pets – Part 1 to read the first part of this article.

Many pet keepers feed their toads heavily on pink and even adult mice. This is a bad idea and will eventually lead to eye, kidney and liver problems. While these aggressive predators certainly take the occasional rodent or lizard in the wild, research has shown that insects, spiders and other invertebrates form the vast majority of their natural diet. In captivity, a goldfish, minnow or shiner can be offered every month or so, perhaps a pink mouse every 6-8 weeks, but limit their intake of vertebrates. Do not feed mice other than pinkies – toads swallow their food alive, and sooner or later they will be injured by a mouse’s sharp teeth.

Marine Toads take readily to tong or even hand feeding (use plastic tongs). Canned insects, such as Can O’ Grasshoppers and Can O’ Pillars should be hand-fed to increase dietary variety.

Wild caught insects, collected from pesticide-free areas, should be offered whenever possible. 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. Avoid using spiders, stinging and brightly -colored insects and fireflies, and do not collect during times when your area is being commercially sprayed for mosquito control.

My Marine Toads relish cicadas, katydids, grasshoppers, beetles of all types, moths, tree crickets, caterpillars, sow bugs and most everything else I come up with. Most of my amphibians feed largely upon wild-caught invertebrates throughout the summer, but even a few beetles plucked from a screen door every night or so will go a long way in keeping your pet in the peak of health.

Social Groups
Marine Toads coexist fairly well together, but bear in mind that they need a lot of room and must be kept scrupulously clean. Fighting is rare, but large animals will out-compete smaller ones for food, so hand-feed if in doubt.

Captive Longevity
The published longevity record is 24 years. Two that I acquired as adults are, at last report, still going strong after 16 years.

Handling and Enrichment
Marine Toads learn very quickly where their meals lie, and will soon greet you as you approach their terrarium. They do not enjoy being held, however, and like all amphibians are subject health problems once the skin’s mucus covering is removed. Handle them – carefully and with clean, wet hands – only when necessary.

Toads in general and this species in particular secrete extremely virulent skin toxins and must be treated with care. Always wash thoroughly after handling them, and never touch your mouth or eyes before doing so. Do not handle Marine Toads if you have a cut in your skin, no matter how tiny it may be. Children and pets must be prevented from coming in contact with these animals, to the point of installing a lock on the terrarium if you are at all unsure. Toads that are licked or swallowed can cause life-threatening reactions.

Marine Toads benefit from hunting opportunities, and remain much more active and alert when provided such on a regular basis. Allow non-threatening insects (crickets may chew on cold or debilitated animals) such as caterpillars, katydids and grasshoppers to roam about their tank when possible. Better still, set your toads up in a secure area outdoors near some over-ripe fruit (to draw beetles and butterflies) or a bush crawling with caterpillars, sit back and enjoy!

Breeding
Egg-laying in the wild is generally in response to the onset of rainy periods, and such may occur if the toads are provided with “artificial rain” in captivity (more on this in the future). Captives sometime breed spontaneously as well. The tadpoles are fairly hardy – please write in if you are fortunate enough to have a breeding pair.

Miscellaneous
In some situations, Marine Toads fare well in semi-freedom. They stay quite close to favored territories – the same 5-6 individuals hunted outside my kitchen in Costa Rica every night for several weeks.

While working at the Bronx Zoo, I kept a few at liberty below a row of exhibits, and another small group in a greenhouse. Here they fed upon crickets, roaches, centipedes, spiders and the like, and grew quite fat. They never failed to emerge from their shelters when I arrived each morning, waiting in a semi-circle for the treats (earthworms and crayfish) they had come to expect. They really are among the most responsive of the amphibians – I highly recommend one if you have the space.

A great deal of information about Marine Toads is posted at:
http://www.globalamphibians.org/servlet/GAA?searchName=Bufo+marinus