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

Madagascar’s Mantellas or Golden Frogs (Family Mantellidae) are, in many ways, the ecological equivalents of Latin America’s Poison Frogs (Family Dendrobatidae), and illustrate nicely the concept of convergent evolution – unrelated animals from different parts of the world that have developed similar adaptations.  Although less commonly kept than the poison frogs, these tiny, brilliantly-colored gems are gaining in popularity.  Following is a brief overview of the group.

Range and Diversity

Mantellas are found only on Madagascar, off the southeast coast of Africa, and are unique enough to warrant their own family, Mantellidae.  Sixteen species have been described thus far, but that number will almost certainly increase as the group is studied more closely.  Nearly all are exceptionally colorful – more so than the better known Poison Frogs (Dendrobates spp.) in many cases.

Similarities to Poison Frogs

Both Mantellas and Poison Frogs are small, brightly-colored, diurnal (active by day), and usually make little attempt to conceal themselves.  All forage on land or in trees, are protected by virulent skin toxins, exhibit complex breeding behaviors, and lay eggs in on land.

Mantella reproductive strategies roughly follow those of the Poison Frogs.  Males call during the day from exposed sites on land – light markings on the vocal sacs may serve as a visual stimulus to females.  They wrestle for dominance, with the loser being flipped onto his back but otherwise unharmed. Ten to thirty eggs, which are fertilized externally, are deposited in nests below leaf litter.

Tadpole development has been little studied; those which have been researched hatch in 2-7 days and wriggle or are washed by rain to temporary pools and brooks.  They feed upon algae and decaying plants and animals, and transform into frogs in 6-8 weeks.  Sexual maturity is attained in 12-14 months.

Mantellas in the Terrarium

Mantellas may be kept in much the same manner as most poison frogs but, being even smaller, they are a bit harder to feed.  A source of springtails, fruit flies and pinhead crickets is a must.

Despite their diminutive statures, Mantellas are efficient predators with quite large appetites – a 1.8 inch long Bronze Mantella (Mantella betsilio) was observed to consume 53 ants in just 30 minutes!

 

Further Reading

A review of the status of the various mantellas and the CITES proposal for their protection is posted here.

The pine, bull and gopher snakes are a complex of 15 species that range from southern Canada through the United States and Mexico to Guatemala.  Large (to 8 feet), powerful constrictors, most species are well-studied and long-established in captivity.  The Black Pine Snake (Pituophis melanoleucus lodingi) remains, however, elusive in the wild and less well-represented in captivity.

I first worked with this striking snake at the Staten Island Zoo, home to one of the country’s most impressive snake collections, and have longed to observe it in the wild ever since.

Classification and Description

The Black Pine Snake is a melanistic form of the northern pine snake (P. m. melanoleucus) that has been given subspecies status.  One other subspecies, the Florida Pine Snake (P. m. mugitus), has been described. The Louisiana Pine Snake (pictured here) is now classified as a distinct species, P. ruthveni.

Uniformly black (rarely dark brown) above and below, the Black Pine is stoutly built.  They average 5 feet in length, with a record of 6 ½ feet.

Range and Habitat

This rare snake is limited to a few localized sites in extreme eastern Louisiana, southwestern Alabama and, possibly, Mississippi.

It is found only in association with the sandy soils of Longleaf Pine communities, a threatened habitat.  The Black Pine Snake spends most of its life underground, within pocket gopher burrows or the root systems of rotting pines.

Status

This snake has an extremely limited range and is protected by the states in which it occurs.  In the past, habitat development and collection for the pet trade threatened its survival.  Captive populations are well-established in both zoos and the private sector.

Reproduction

Mating occurs in the spring, and 3-24 eggs are laid in June-August.  The clutch is hidden in a burrow or, less frequently, below a rock or log.  The young hatch in 64-79 days at 12-18 inches in length.

Diet

The natural diet has not been thoroughly documented, but likely includes deer mice, ground squirrels, chipmunks, cotton rats, rabbits, pocket gophers and ground-nesting birds and their eggs.  Prey is killed by constriction.

This and related species usually hunt below ground, within the burrows of gophers and other rodents.  Where space does not permit constriction, these powerful snakes kill rodents by forcibly pressing them against the burrow walls.  Often a number of animals will be killed in this manner before the snake stops to feed.

Pine snakes are much valued for their rodent-catching abilities and are sometimes released around farms and grain storage facilities.

Defense

When threatened, pine snakes put on an impressive display – the body swells with inhaled air that is expelled in a loud hiss, while the tail vibrates rapidly and the head is flattened.  The snake rears up in a series of ‘S” shaped curves and strikes repeatedly.  Most will flee if given the opportunity, but they do not hesitate to bite.

Husbandry

Black Pine Snake care is fairly straightforward, and follows that of rat snakes and other Colubrids.  Please write in for further information, or see Black Rat Snake Care and Natural History for husbandry guidelines.

Captive born specimens are usually calm, although the few I have worked with were a bit high strung.  Being largely fossorial in the wild, they are ill at ease if forced to remain in the open.  Even long term captives spend a good deal of their time within shelters.

Further Reading

You can read about conservation efforts for Black Pine Snakes in Alabama here.

 

The Tropical Girdled Lizard (Cordylus tropidosternum) is the most readily available of the 30+ Cordylus species, and offers an excellent introduction to the group.  It is sometimes sold as the “Armadillo Lizard”, confusing purchasers who had in mind another (and, at $1,200+ each, vastly more expensive!) species with the same common name, C. cataphractus.  It also occasionally appears under the name “East African Spiny-tailed Lizard”.

Tropical Girdled Lizards in Captivity

Don’t let their inexpensive price tag mislead you – Tropical GirdledLlizards are no less interesting in appearance or behavior than their pricey cousins. In fact, the “true” Armadillo Lizard, C. cataphractus, which is no longer exported from South Africa, is one of the shyest reptiles I’ve ever encountered.

When kept properly, these southeast African natives may reward you by reproducing, always a thrill for responsible herp keepers (judging from the size of the young, the event is less thrilling for the moms – please see below!).  While not bold, they are no as retiring as most related species, and are relatively easy to observe.

Girdled Lizards give birth to 1-4 huge live youngsters.  The hatchling pictured here, born at the Maritime Aquarium in Connecticut, is one of a litter of 2 – their total mass seemed to be nearly half that of their mother.

 

Further Reading

Two subspecies of tropical Girdled Lizards appear in the pet trade; to help determine which you have, and for a key to other species in the genus, please see this reference.

Over the last several years I have helped to set up new reptile and amphibian exhibit areas for The Maritime Aquarium in Norwalk, CT (long known for its excellent collection of native marine life).  To learn more, please click here.

 

In 1705, a painting of a Pink-toed Tarantula consuming a hummingbird, published in Maria S. Merian’s book on the insects of Suriname, aroused so much attention (and horror!) that all New World tarantulas are commonly termed “bird-eating spiders” to this day.  It seems now that amphibian fanciers have their own dramatic bird-eater – Limnonectes megastomias, an aquatic frog recently described from 3 locations in Thailand.

An Aquatic Ambush Predator

The newly discovered frog is largely aquatic, and apparently catches birds that come to the water’s edge to drink – quite a unique feeding strategy for a frog (I once saw a surprising film of African Side-necked Turtles catching doves in this manner).

It is assisted in hunting by large (to 2 inch) “fangs” and a head that is disproportionately large for the body.  The fangs are not true teeth but rather extensions of the jawbone, known as odontoid processes.  The African Bullfrog and the South American Horned Frogs, known also for consuming vertebrates (and biting the hand that feeds them!), also sport odontoid processes.  Insects and other frogs have also been recorded as prey.

Same Bodies, Larger Heads – Sexual Dimorphism

Interestingly, the heads and “teeth” of male Bird-eating Frogs grow much larger than those of females, despite similar body sizes.  In certain other creatures (i.e. Barbour’s Map Turtles) this strategy allows the sexes to consume different diets and, it is theorized, avoid competition.  Researchers also believe that the enlarged teeth are used in combat, as many males carry scars.

So Much to Discover

There are over 50 species classified in the genus Limnonectes- the new “bird-eater” appears most closely related to the Kuhl’s or Large-Headed Frog, L. Kuhlii, but little is known of its natural history (the photo attached is of a Kuhl’s frog).

This new species was first observed at the Sakaerat Environmental Research Station, an area that has been extensively studied for 40 years.  The fact that such a large and unique frog was able to remain undiscovered in this area illustrates the untold opportunities open to those who wish to get out and look around in just about any habitat – recently a new centipede was discovered in NYC’s Central Park!

Further Reading

Another toothed amphibian behemoth, the African Bullfrog, also takes quite large prey…to read about a most unusual frog meal, please see my article An Appetite for Cobras.

 

Limnonectes kuhlii image referenced from wikipedia and originally posted by W. Djatmiko

Please see Part I of this article for background information on these snake-keepers’ favorites.  Garter Snakes and the closely related ribbon and water snakes usually make hardy captives, yet there are very few records of individuals surviving over 10 years.  I believe this may have to do with some of their unique environmental and dietary needs (I’ll cover temperature, light and diet in Part III of this article).

Natural vs. Captive Habitats

Nearly all garter and ribbon snakes favor swamps, wet meadows, pond edges and other moist habitats.  Oddly, however, they are very susceptible to skin infections (“blister disease”) when kept on damp substrates – even more so than snakes native to dry environments.  This holds true even for those that spend a great deal of time in the water, such as the Aquatic Garter Snake (Thamnophis couchi), the Ribbon Snake (T. sauritus) and the True Water Snakes (Nerodia sp.).

While all should be given water in which to soak, the substrate must remain dry.  The aforementioned species may be kept in semi-aquatic terrariums that allow for swimming, but they must have access to warm, dry basking sites (branches over water work well).  Shy specimens that will not bask should be moved into terrestrial situations with just a bowl of water available.

Curing Blister Disease

A Northern Water Snake (Nerodia  sipedon) that I kept decades ago developed skin blisters after only 2 weeks of a largely aquatic existence.  I wrote to famed reptile man Wayne King, then curator of reptiles at the Bronx Zoo.  His advice to move the animal to a dry terrarium and provide a warm but sheltered basking site worked like a charm, and the snake’s skin condition cleared within 10 days.

Further Reading

An excellent article on the unique Aquatic Garter Snake, including habitat photos, is posted here.